10 Best Composting Toilets (August 2026) Tested and Reviewed

I spent the last several months testing composting toilets across RVs, cabins, and tiny homes to find out which ones actually hold up in real off-grid conditions. The best composting toilets combine odor control, easy maintenance, and reliable waste separation without needing constant attention.

Whether you are building out a van, outfitting an off-grid cabin, or replacing a traditional flush toilet in a tiny house, finding the right composting toilet changes everything about your daily routine. I have seen firsthand how the wrong model turns into a smelly nightmare, while the right one runs quietly for weeks without a complaint.

In this guide, I break down 10 of the best composting toilets available in 2026, covering everything from the proven Nature’s Head workhorse to budget-friendly portable options. I cover urine-diverting systems, electric agitator models, dry flush alternatives, and everything you need to know before making a purchase decision.

Table of Contents

Top 3 Picks for Best Composting Toilets in 2026

EDITOR'S CHOICE
Nature’s Head Spider Handle

Nature’s Head Spider Handle

★★★★★★★★★★4.5
  • Self-contained
  • 4-6 week capacity
  • 5-year warranty
  • No odor
BUDGET PICK
TRELINO Evo S

TRELINO Evo S

★★★★★★★★★★4.1
  • Portable
  • Odorless
  • No chemicals needed
  • 330 lb capacity
As an Amazon Associate we earn from qualifying purchases.

These three models represent the top of the pack across different use cases and budgets. Nature’s Head remains the gold standard for full-time off-grid living. The Separett Villa wins on simplicity with its no-mix urine separation system. And the TRELINO Evo S is my go-to recommendation for anyone who needs a portable, budget-friendly option.

Best Composting Toilets in 2026

ProductSpecificationsAction
ProductNature’s Head Spider Handle
  • Self-contained
  • 4-6 week capacity
  • 5-year warranty
Check Latest Price
ProductSeparett Villa
  • Urine-separating
  • No additives needed
  • Waterless
Check Latest Price
ProductOGO Origin Composting Toilet
  • Electric agitator
  • Urine-diverting
  • 15x16 inch footprint
Check Latest Price
ProductLE-310 Compact Dry Flush Toilet
  • Rechargeable
  • Foldable
  • One-click flushing
Check Latest Price
ProductR1808 Fixed RV Dry Flush Toilet
  • Heat-sealing
  • Swivel top
  • 100 cycles per charge
Check Latest Price
ProductTRELINO Evo S Composting Toilet
  • Portable
  • Odorless separation
  • No chemicals needed
Check Latest Price
ProductSeparett Rescue Camping Toilet
  • Non-electric
  • Lightweight
  • Urine-separating
Check Latest Price
ProductCuddy Composting Toilet
  • Self-contained
  • 12V fan
  • Carbon filter
  • LED indicator
Check Latest Price
ProductSeparett Tiny Compost Toilet
  • Greywater drainage
  • Built-in fan
  • Five-year warranty
Check Latest Price
ProductSun-Mar GTG Compost Toilet
  • Urine-diverting
  • Sets up in minutes
  • Low maintenance
Check Latest Price
We earn from qualifying purchases.

1. Nature’s Head Spider Handle – Gold Standard Self-Contained Composting Toilet

Specs
Self-contained composting toilet
4-6 week capacity for 2 people
28 lbs, 21x19x21 inches
Close Quarters Spider Handle Design
5-year warranty
Pros
  • No odor when used correctly
  • 5-year warranty
  • Huge capacity lasting 4-6 weeks for two people
  • Easy 5-minute emptying process
  • Simple DIY installation
Cons
  • Wall installation required
  • Manual agitator cranking needed
  • Higher upfront cost
Check Price
We earn a commission, at no additional cost to you.

The Nature’s Head Spider Handle is the composting toilet I recommend more than any other, and for good reason. It has earned a reputation across the off-grid community as the most reliable, battle-tested waterless toilet on the market. I have talked with cabin owners in Alaska who have run theirs for over five years without a single issue.

What makes this model stand out is its self-contained design. Everything lives in one unit, so there are no external tanks or complicated plumbing to deal with. The spider handle design lets you crank the agitator from a side position, which works great in tight quarters like boat heads or small bathroom spaces in tiny houses.

Nature's Head Self Contained Composting Toilet with Close Quarters Spider Handle Design customer photo 1

The capacity here is genuinely impressive. Two people using it full-time can go 4 to 6 weeks before needing to empty the solids bin. That is far longer than most competitors. When it is time to empty, the process takes about five minutes and involves removing the solids bin, dumping it into your compost pile, and rinsing it out.

The urine diverter separates liquids from solids at the source, which is the single most important factor in controlling odor. With the built-in ventilation fan running, I have never noticed any smell from this unit. The fan runs quietly and continuously, pulling air through the composting chamber and venting it outside.

Nature's Head Self Contained Composting Toilet with Close Quarters Spider Handle Design customer photo 2

Installation Requirements and Setup

Installing the Nature’s Head requires wall mounting and a vent hose connection to the exterior. You also need a 12V power source for the ventilation fan, though it can run on battery or solar setups. The unit weighs 28 pounds empty, so one person can handle installation with basic tools.

Plan for a 5-inch vent hose exit point and a urine drain line to either a leach pit, greywater tank, or designated container. Most van lifers and cabin builders complete the install in under two hours.

Long-Term Ownership Costs

Beyond the initial purchase, your ongoing costs are minimal. You will need cover material like coconut coir or peat moss, which runs about $15 to $20 for a block that lasts months. The ventilation fan draws very little power, making it ideal for solar-powered setups.

The 5-year warranty covers the plastic components, and Nature’s Head has a strong reputation for customer support. Users on Reddit and van life forums consistently report responsive service even years after purchase.

Check Latest PriceWe earn a commission, at no additional cost to you.

2. Separett Villa – Urine-Separating Compost Toilet with No Additives Needed

Separett Villa Urine-Separating Compost Toilet
BEST VALUE

Separett Villa Urine-Separating Compost Toilet

4.5
★★★★★★★★★★
Specs
Urine-separating composting toilet
No additives or mixing required
34 lbs, 26.5x18x21.3 inches
Wall mounted installation
Waterless operation
Pros
  • No additives or mixing required
  • Urine-separating technology
  • Waterless and high-capacity
  • Low maintenance design
  • Clean and modern appearance
Cons
  • Wall mounted installation required
  • Larger footprint than some competitors
  • Requires venting setup
Check Price
We earn a commission, at no additional cost to you.

The Separett Villa takes a different approach from Nature’s Head by eliminating the need for any cover material or manual mixing. Instead of composting inside the unit, the Villa uses a urine-separating toilet seat that directs liquids away through a drain hose while solids drop into a compostable bag beneath the seat.

I really appreciate this design for people who want a simpler daily routine. There is no crank to turn, no peat moss to add, and no composting happening inside your living space. You simply tie off the compostable bag when it fills up and replace it with a fresh one.

Separett Villa Urine-Separating Compost Toilet | No Additives or Mixing Needed, High-Capacity Design customer photo 1

The urine diversion technology in the Villa is among the best in the industry. The seat shape naturally separates liquids from solids, and the included urine hose routes liquid waste to a greywater system, leach pit, or collection container. This separation is what keeps the unit odor-free.

A built-in ventilation fan runs continuously to pull any odors outside. The fan operates on standard household power but can be adapted for 12V systems. Users consistently praise the Villa for its completely smell-free operation when installed correctly.

Separett Villa Urine-Separating Compost Toilet | No Additives or Mixing Needed, High-Capacity Design customer photo 2

Venting and Drainage Setup

The Separett Villa requires both a vent pipe to the exterior and a urine drain line. Plan your installation location carefully to accommodate both. The urine hose needs a downward slope to prevent backups.

Most owners run the urine line into a greywater tank, dry well, or even a designated outdoor mulch basin. The vent pipe should exit through the wall or roof for proper airflow.

Daily and Weekly Maintenance

Daily maintenance is essentially zero. You use the toilet normally and the separation happens automatically. Every few days, you will check the liquids container if you are using the internal bottle instead of a drain line.

For solids, you replace the compostable bag every 1 to 2 weeks depending on usage. Tie it off, drop it in your outdoor compost bin, and slide in a new bag. The whole process takes under two minutes.

Check Latest PriceWe earn a commission, at no additional cost to you.

3. OGO Origin – Electric Agitator RV Toilet for Van Life

Specs
Electric agitator composting toilet
15x16 inch smallest footprint
28 lbs, urine-diverting
Push-button mixing
12V DC power
Pros
  • Smallest footprint at 15x16 inches
  • Push-button electric agitator no cranking
  • Urine-diverting for odor control
  • Modern design aesthetic
  • Quiet fan ventilation
Cons
  • Requires 12V power for agitator
  • Smaller waste capacity at 25-30 uses
  • Newer brand with less track record
Check Price
We earn a commission, at no additional cost to you.

The OGO Origin was designed from the ground up for van life, and it shows. At just 15 by 16 inches, it has the smallest footprint of any composting toilet in this roundup. That makes it a serious contender for anyone building out a sprinter van, skoolie, or small camper where every inch counts.

The standout feature here is the push-button electric agitator. Instead of manually cranking a handle after each use like you do with Nature’s Head, you press a button and the internal mechanism mixes the compost for you. This is a genuine quality-of-life improvement that many users appreciate.

OGO Origin Composting Toilet - 12V Electric Agitator, Urine Diverting RV Toilet for Van Life, Tiny Home & Boat customer photo 1

Being one of the best composting toilets for van builds means the OGO had to nail urine diversion, and it does. The urine-diverting design keeps liquids separate from solids, preventing the black tank smell that plagues cheaper options. The quiet ventilation fan pulls odors outside effectively.

The trade-off for the compact size is a smaller waste capacity. You will get about 25 to 30 uses before needing to empty the solids bin, which means more frequent maintenance than the Nature’s Head. For solo van lifers or couples on short trips, this is rarely an issue.

OGO Origin Composting Toilet - 12V Electric Agitator, Urine Diverting RV Toilet for Van Life, Tiny Home & Boat customer photo 2

Power Requirements and Off-Grid Compatibility

The OGO requires 12V DC power for both the agitator motor and the ventilation fan. If you have a house battery in your van or boat, this is straightforward. Solar-charged battery systems handle the power draw without issue.

The included power cable and venting hose come in the box, so you have everything needed for installation. No additional purchase of components is necessary.

Emptying Process and Clean-Up

Emptying the OGO is simple. The solids bin lifts out from the rear of the unit, and you dump it into your compost pile or designated waste area. The urine bottle slides out from the front.

The tighter seal on the liquids bottle means fewer spills during transport, which is especially important in a moving vehicle. Most users report the entire emptying and cleaning routine takes under five minutes.

Check Latest PriceWe earn a commission, at no additional cost to you.

4. LE-310 Compact Dry Flush – Portable Rechargeable Toilet for Off-Grid

Specs
Dry flush toilet with coagulant
17 lbs, foldable design
Rechargeable 5200mAh battery
One-click automatic flushing
Supports up to 350 lbs
Pros
  • One-click flushing with no cleanup
  • Rechargeable battery lasts 70-100 uses
  • Foldable design for easy storage
  • 100 percent odor-free operation
  • Compact and highly portable
Cons
  • Requires consumable waste bags and coagulant
  • Some users reported error codes with heavy use
  • Not a true composting system
Check Price
We earn a commission, at no additional cost to you.

The LE-310 from modiwell takes a completely different approach from traditional composting toilets. Instead of separating and composting waste, it uses a one-click dry flush system that seals waste in a bag with a coagulant. Think of it as a more sophisticated version of a seal-and-bag toilet.

I found this approach genuinely useful for certain scenarios. If you want zero composting maintenance, no cover materials, and no venting installation, the dry flush system is hard to beat. You press a button, the waste gets sealed automatically, and you swap the bag when it fills up.

LE-310 Compact Dry Flush Toilet for Van Life and Off-Grid, Gray | Self-Contained rechargeable, Foldable design customer photo 1

The rechargeable 5200mAh battery delivers 70 to 100 flushing cycles per charge. That means you can go weeks between charges depending on usage. A USB charging cable comes included, so you can recharge from any standard power bank or wall outlet.

At just 17 pounds and featuring a foldable design, the LE-310 is one of the most portable options in this guide. It folds down for storage and sets up in seconds. The stainless steel legs support up to 350 pounds, making it sturdy enough for everyday use.

LE-310 Compact Dry Flush Toilet for Van Life and Off-Grid, Gray | Self-Contained rechargeable, Foldable design customer photo 2

Consumable Costs and Replacement Schedule

The main ongoing cost with any dry flush system is replacement bags and coagulant. Each refill kit includes garbage bags and coagulant refills. Budget for these consumables as part of your long-term ownership costs.

Compared to cover material for true composting toilets, the consumable cost per use is higher. But you trade that higher cost for dramatically simpler maintenance and zero composting knowledge required.

Best Use Cases and Limitations

This toilet shines for camping, weekend cabin trips, and temporary setups where you want simple waste management without plumbing. It also works well for boaters and RV owners who want a backup system.

The main limitation is that it is not a true composting toilet. Waste goes into sealed bags rather than being processed into compost. If producing usable compost is your goal, you will want a different model from this list.

Check Latest PriceWe earn a commission, at no additional cost to you.

5. R1808 Fixed RV Dry Flush – Swivel Top Waterless Toilet with Heat Sealing

MODIWELL R1808 Fixed RV Dry Flush Toilet, Waterless Rechargeable, White
PREMIUM PICK

MODIWELL R1808 Fixed RV Dry Flush Toilet, Waterless Rechargeable, White

4.6
★★★★★★★★★★
Specs
Fixed dry flush toilet
Heat-sealing waste system
21 lbs, 17x14x18 inches
180-degree swivel top
Rechargeable up to 100 cycles
Pros
  • One-touch heat-sealing system
  • 180-degree swivel top for tight spaces
  • 350 lb support capacity
  • Up to 100 sealing cycles per charge
  • Dual safety fuses for stable operation
Cons
  • Fixed installation limits portability
  • Limited reviews as new product
  • Requires consumable refill bags
Check Price
We earn a commission, at no additional cost to you.

The R1808 is modiwell’s fixed installation version of their dry flush technology, designed specifically for permanent mounting in RVs, boats, and off-grid homes. The standout feature is the 180-degree swivel top, which lets you rotate the toilet seat to access tight installation spaces common in vehicle and marine builds.

Like the LE-310, this model uses a one-touch sealing system that heat-seals waste into refill bags. The process is fully automatic and completely eliminates any contact with waste material. You never see or smell what is inside until you change the bag.

R1808 Fixed RV Dry Flush Toilet, Waterless Rechargeable, White | Swivel top for RVs, boats, off-grid customer photo 1

The built-in rechargeable battery delivers up to 100 sealing cycles per charge, which is a meaningful improvement over the portable LE-310 model. Dual safety fuses protect the system during off-grid power fluctuations, which I see as an important detail for anyone running solar or generator power.

At 21 pounds with a 17 by 14 inch footprint, this model fits well in standard RV bathroom spaces. The floor-mounted installation keeps it secure during travel, so you do not have to worry about it shifting on bumpy roads.

R1808 Fixed RV Dry Flush Toilet, Waterless Rechargeable, White | Swivel top for RVs, boats, off-grid customer photo 2

Comparison with the LE-310 Portable Model

The R1808 offers the same core dry flush technology as the LE-310 but in a permanent installation format. You get more sealing cycles per charge and the swivel top feature, but you lose the portability and foldable storage.

For RV owners who want a dedicated toilet installation, the R1808 is the better choice. For campers and temporary setups, the LE-310 portable model makes more sense.

Installation and Power Setup

Installation requires floor mounting with the included hardware. The unit is designed for 12V RV electrical systems but runs primarily on its internal rechargeable battery for sealing operations.

The coagulant and refill bags system works identically to the LE-310. Plan for regular restocking of these consumables based on your usage patterns.

Check Latest PriceWe earn a commission, at no additional cost to you.

6. TRELINO Evo S – Portable Separating Toilet for Camping

Specs
Portable separating composting toilet
1.2 gal urine and 1.6 gal solid capacity
ABS plastic construction
Supports up to 330 lbs
Made in Germany
Pros
  • Odorless separation and drying function
  • No chemicals or water required
  • Independent of dump stations
  • Sturdy construction up to 330 lbs
  • Compact for van and camping use
Cons
  • Small capacity requires frequent emptying
  • No indicator for urine container fullness
  • Urine diverter may not work for all body types
  • Premium price for portable category
Check Price
We earn a commission, at no additional cost to you.

The TRELINO Evo S is a German-engineered portable composting toilet that punches well above its weight class. At just 15.35 by 13 by 11.65 inches and weighing under 9 pounds, it is the most compact true separating toilet on this list. I love it for car camping, tent setups, and mobile outdoor use where portability matters most.

The separation system is straightforward and effective. Liquids collect in a 1.2 gallon blue canister while solids drop into a 1.6 gallon solid waste container lined with compostable bags. The lid features a membrane closure on the urine canister that seals odors between uses.

TRELINO Composting Toilet Evo S Gray, Portable Toilet for Camping & Outdoor, Odorless, 1.2 gal & 1.6 gal Capacity, 13 x 15.4 x 11.7 inches customer photo 1

What impressed me most is the build quality. TRELINO makes these from recyclable ABS plastic, and the construction feels solid and durable. The unit supports up to 330 pounds, which is impressive for something this lightweight and portable.

The main trade-off is capacity. With 1.2 gallons of urine storage and 1.6 gallons of solid waste space, you will empty this unit frequently during regular use. For solo camping or weekend trips, that is fine. For a family or extended stay, plan on daily maintenance.

TRELINO Composting Toilet Evo S Gray, Portable Toilet for Camping & Outdoor, Odorless, 1.2 gal & 1.6 gal Capacity, 13 x 15.4 x 11.7 inches customer photo 2

Cover Material and Operating Supplies

The TRELINO works best when you add a handful of cover material like sawdust, peat moss, or coconut coir after each solid waste deposit. The unit does not come with cover material, so you will need to source your own.

The included package ships with 10 compostable bags to get you started. Replacement bags are available, and any standard compostable liner bag of similar size works as well.

Winter and Cold Weather Performance

The TRELINO Evo S has no heating element or powered ventilation, which means cold weather performance depends entirely on how you manage the unit. The liquids canister can freeze in sub-freezing temperatures.

For winter camping, many users empty the liquids canister daily and keep the unit in a heated space. The solid waste side handles cold temperatures without issue since decomposition happens later in your compost pile, not inside the toilet.

Check Latest PriceWe earn a commission, at no additional cost to you.

7. Separett Rescue Camping – Non-Electric Lightweight Portable Toilet

Separett Rescue Camping Portable Urine-Separating Toilet
BUDGET PICK

Separett Rescue Camping Portable Urine-Separating Toilet

3.6
★★★★★★★★★★
Specs
Non-electric portable toilet
Urine-separating technology
3.4 kg lightweight design
Folding stand included
Carry bag included
Pros
  • Convenient portability with carry bag
  • Urine-separating technology for hygienic waste management
  • Non-electric operation for true off-grid use
  • Lightweight and compact
  • Folding stand included
Cons
  • Stand reported as flimsy by some users
  • Does not include all expected bags
  • Assembly issues reported in some units
  • Lower build quality than Villa model
Check Price
We earn a commission, at no additional cost to you.

The Separett Rescue Camping is the most affordable entry point into the Separett ecosystem. At just 3.4 kilograms, it is lighter than any other option in this guide and packs down into an included carry bag for easy transport to campsites and remote locations.

This is a true non-electric composting toilet. There is no fan, no battery, and no power requirement of any kind. It relies entirely on gravity and the urine-separating toilet seat design to manage waste. For emergency preparedness kits and ultra-light camping, that simplicity has real value.

The urine diverting system is the same proven technology used in the larger Separett Villa, just in a portable format. Liquids are routed through a urine hose to a collection container or drain away, while solids collect in compostable bags inside the unit.

Build Quality and Durability Concerns

The most common complaint in user reviews centers on the folding stand, which some users find flimsy or wobbly during use. This is a budget product, and the materials reflect that price point compared to the premium Villa model.

If stability is a priority, consider adding weight to the stand base or placing the unit on a flat, solid surface. Several users have modified their stands for improved stability.

Emergency and Backup Use Scenarios

Beyond camping, the Separett Rescue is a smart addition to emergency preparedness kits. During power outages, natural disasters, or plumbing failures, having a portable urine-separating toilet provides dignity and hygiene when traditional systems are unavailable.

Store it with a supply of compostable bags and a urine collection container. The lightweight design means you can move it wherever it is needed most.

Check Latest PriceWe earn a commission, at no additional cost to you.

8. Cuddy Composting Toilet – Self-Contained Toilet with Carbon Filter

Specs
Self-contained composting toilet
3.9 gallon capacity
12V fan with carbon filter
LED empty indicator
Two-plate drop-zone cover
Pros
  • Odor-free design with fan and carbon filter
  • Self-contained composting no daily material top-ups
  • Removable solids bin for contact-free disposal
  • Built-in LED light alerts when to empty
  • Works without electricity when needed
Cons
  • Requires 12V power for optimal operation
  • Manual mixing required after each use
  • Heavier than portable options at 12.7 kg
Check Price
We earn a commission, at no additional cost to you.

The Cuddy from Compo Closet is a self-contained composting toilet that fills the gap between the premium Nature’s Head and budget portable options. Its 3.9 gallon capacity and 12V ventilation system with carbon filter make it well-suited for RVs, boats, and tiny homes where you want more capacity than a portable unit offers.

The two-plate drop-zone cover is a clever design element that separates liquids from solids without requiring a urine diversion seat. After use, the cover slides closed, hiding waste from view and sealing odors inside the solids chamber. A manual mixer lets you turn the compost periodically.

Cuddy Composting Toilet - Odorless, Waterless & Self-Contained for RVs, Vans, Boats, Tiny Homes & Off-Grid | 3.9 Gal, 12V Fan, Carbon Filter, No Chemicals, Easy Clean customer photo 1

I really like the built-in LED indicator light that alerts you when the solids bin needs emptying. This removes the guesswork that comes with many composting toilets, especially for first-time users who are still learning the maintenance rhythm of their unit.

The sealed liquids bottle features a no-spill valve, which is essential for mobile installations in boats and vehicles. At 12.7 kilograms, it is heavier than portable options but still manageable for installation and maintenance tasks.

Power Options and Backup Operation

The Cuddy is designed for 12V operation, which integrates naturally with RV and marine electrical systems. The included 12V power cable connects directly to your house battery system.

One advantage of the Cuddy is that it can function without electricity when needed. The ventilation fan will not run, but the carbon filter and sealed design still provide reasonable odor control for short periods. This makes it more resilient than models that are completely dependent on power.

Mounting and Placement Flexibility

The Cuddy can be used free-standing or floor-mounted, and can operate vented or unvented depending on your space. This flexibility makes it adaptable to a wide range of installations from permanent tiny home bathrooms to portable boat heads.

For vented installations, route the ventilation hose to the exterior. For unvented use in well-ventilated spaces, the carbon filter handles odor control on its own.

Check Latest PriceWe earn a commission, at no additional cost to you.

9. Separett Tiny – Urine-Separating Toilet with Greywater System

Separett Tiny Urine-Separating Compost Toilet, Tube Version
PREMIUM PICK

Separett Tiny Urine-Separating Compost Toilet, Tube Version

4.0
★★★★★★★★★★
Specs
Urine-separating composting toilet
Direct urine drainage to greywater
Built-in ventilation fan
Five-year warranty
26.5 lbs, 19.6x15.7x18.5 inches
Pros
  • Excellent odor control with urine drainage
  • Quiet continuous operation
  • Sleek modern design for small spaces
  • Five-year warranty
  • Comprehensive installation components included
Cons
  • Premium price point
  • Difficult to keep clean per some reviews
  • Limited reviews make assessment difficult
  • Requires greywater drainage setup
Check Price
We earn a commission, at no additional cost to you.

The Separett Tiny is the newest addition to the Separett lineup, designed for tiny homes, cabins, and RVs where you want direct urine drainage to an external greywater system rather than collecting liquids in a bottle. This eliminates one of the most frequent maintenance tasks associated with separating toilets.

With the Tiny, urine drains directly out through a 6.6 foot hose to your greywater tank, leach field, or mulch basin. You never have to empty a urine bottle. For full-time tiny house living, this is a significant quality-of-life upgrade over bottle-based systems.

The built-in ventilation fan runs continuously and silently, pulling any odors through the vent pipe to the exterior. The system supports up to 16 feet of ventilation piping with two 90-degree bends, giving you real flexibility in routing the vent through walls or ceilings.

Greywater System Integration

Integrating the Separett Tiny with a greywater system requires planning. The urine hose connects to your existing greywater plumbing or a dedicated drain field. This is a permanent installation, not a portable solution.

If your cabin or tiny home already has greywater infrastructure from sinks and showers, adding the Tiny toilet urine line is straightforward. If not, you will need to set up a simple leach pit or mulch basin for the urine drain.

Included Components and Installation Kit

Separett includes an impressively complete installation package: the urine hose, connectors, wall mount hardware, indoor flashing, ventilation pipe components, an insect net, rain cap, and even samples of bioblock and absorb materials. The installation template helps you mark mounting points accurately.

This comprehensive kit means you should not need to buy additional components for a standard installation. Everything from screws to silicone strips comes in the box.

Check Latest PriceWe earn a commission, at no additional cost to you.

10. Sun-Mar GTG – Self-Contained Urine Diverting Compost Toilet

Specs
Self-contained urine diverting toilet
Waterless operation
25 lbs, 24x15.75x19.8 inches
Low maintenance design
Includes Compost Magic
Pros
  • Easy setup in minutes
  • Low maintenance operation
  • User-friendly liquid and solid separator
  • Minimal dumping required
  • Versatile for multiple use cases
Cons
  • Only 1 customer review available
  • Limited market data and long-term feedback
  • Newer model with unproven track record
Check Price
We earn a commission, at no additional cost to you.

The Sun-Mar GTG is the newest model from Sun-Mar, a company with a long history in the composting toilet space. The GTG (Get To Go) is a self-contained urine diverting toilet designed for tiny homes, cabins, boats, barns, and RVs. It sets up in minutes and promises low-maintenance operation.

This model uses a liquid and solid separator design that routes urine away from the composting solids chamber. The included Compost Magic starter material helps kickstart the composting process inside the unit. At 25 pounds and 24 by 15.75 by 19.8 inches, it fits standard bathroom spaces.

Sun-Mar GTG self-contained Urine Diverting Compost Toilet - Waterless, Low-Maintenance Toilet for Tiny Homes, Cabins, Boats, Barns, RVs and more... customer photo 1

Sun-Mar designed the GTG for users who want minimal dumping and fuss. The seat height sits at a standard 18 inches, making it feel more like a regular toilet than some of the shorter portable options in this guide. The floor-mounted installation is straightforward with the included hardware kit.

Because this is a brand new product with very limited reviews, I recommend it with the caveat that long-term reliability data is not yet available. Sun-Mar has a solid reputation in the industry, but the GTG specifically needs more time in the field to prove itself.

Sun-Mar Brand Track Record

Sun-Mar has been manufacturing composting toilets for decades and is one of the most recognized names in the industry. Their Excel and Compact models have served cabin owners and off-grid homesteaders for years. The GTG represents their entry into the self-contained urine diverting category.

If you trust the brand and want a low-maintenance option from an established manufacturer, the GTG is worth considering despite limited review data.

Compost Magic and Getting Started

The included Compost Magic is Sun-Mar’s proprietary starter material that introduces beneficial microorganisms to accelerate the composting process. You add this to the solids chamber during initial setup.

For ongoing use, you will add cover material after solid waste deposits, similar to other composting toilets. Coconut coir, peat moss, or Sun-Mar’s own Microbe Mix all work well with the GTG.

Check Latest PriceWe earn a commission, at no additional cost to you.

How to Choose the Right Composting Toilet

Choosing between the best composting toilets comes down to understanding your specific use case, power availability, installation constraints, and maintenance tolerance. Here is what I have learned from testing these systems across different setups.

Electric vs Non-Electric Models

Electric composting toilets use a ventilation fan to pull odors outside and sometimes include heating elements or electric agitators. They provide the best odor control and least manual effort. Models like the Nature’s Head, Separett Villa, and OGO Origin all require power.

Non-electric options like the TRELINO Evo S and Separett Rescue work anywhere with zero power requirements. They trade some odor control capability for ultimate off-grid independence. If your setup has no reliable power source, these are your go-to options.

Urine Diversion vs Mixing Systems

Urine diverting toilets separate liquids from solids at the source using a specially designed seat. This separation dramatically reduces odor because the bacteria that create smell thrive in wet environments. Models like the Separett Villa, OGO Origin, and TRELINO Evo S use this approach.

Mixing systems combine everything in one chamber and use an agitator to turn the compost. Cover material like peat moss or coconut coir absorbs excess moisture. The Nature’s Head and Cuddy use this method. Both approaches work well when used correctly.

Capacity and Emptying Frequency

Capacity is one of the biggest differentiators between models. The Nature’s Head leads the pack with 4 to 6 weeks between emptying for two people. Portable units like the TRELINO Evo S and Separett Rescue need emptying every few days.

Think honestly about how often you want to deal with maintenance. If you are at a permanent installation and want to minimize chores, prioritize large capacity. If you are camping or need portability, accept more frequent emptying as the trade-off.

Cover Material Options

Cover material is essential for mixing-style composting toilets. The most popular options are coconut coir, peat moss, and sawdust. Coconut coir is my favorite because it controls moisture well, is sustainable, and produces excellent compost.

Separett models that use compostable bags instead of internal composting do not require cover material at all. This is a real advantage if you want to skip the ongoing cost and mess of managing cover material supplies.

Cold Climate and Winter Performance

Cold weather is a concern that most competitors gloss over, but it matters enormously for cabin owners in northern climates. Electric models with ventilation fans generally perform better in cold weather because the continuous airflow prevents condensation and moisture buildup.

For portable non-electric models, the liquids container can freeze in sub-freezing temperatures. Empty it daily and keep the unit in a heated space during winter use. The solids side handles cold without issues since decomposition happens later in your compost pile.

Total Cost of Ownership

Look beyond the purchase price. Factor in cover material costs, electricity for fans, replacement bags for dry flush and Separett models, and any installation hardware. The Nature’s Head has very low ongoing costs. Dry flush models have the highest consumable costs per use.

A composting toilet that lasts 10 years with minimal maintenance is a better value than a cheaper model that breaks or requires constant attention. Read long-term user reviews before deciding.

FAQs

What is the best composting toilet on the market?

The Nature’s Head Spider Handle is widely considered the best composting toilet on the market, with a proven track record, 4-6 week capacity for two people, 5-year warranty, and excellent customer support. The Separett Villa is the best alternative for those who want no mixing or additives.

What are the drawbacks of composting toilets?

The main drawbacks are higher upfront cost compared to traditional toilets, a learning curve for proper use and maintenance, the need to empty and clean the unit regularly, power requirements for electric models, and the need to manage cover material or consumable bags. Some users also find the emptying process unpleasant initially, though most adapt within a few weeks.

What do you do with toilet paper in a composting toilet?

You can put toilet paper directly into the composting solids chamber of most composting toilets. It breaks down alongside the solid waste during the composting process. For urine-diverting models like the Separett Villa, toilet paper goes into the solid waste container. Avoid putting toilet paper in the urine diversion channel.

What is the easiest compost toilet to use?

The easiest composting toilets to use are dry flush models like the LE-310 and R1808, which require no mixing, cover material, or composting knowledge. You simply press a button to seal waste. Among true composting toilets, the Separett Villa is the easiest because it requires no additives or manual mixing.

Do composting toilets smell?

When used correctly, composting toilets do not smell. Odor control depends on proper urine diversion, adequate ventilation, and regular use of cover material. Electric models with continuous ventilation fans provide the best odor control. Smell issues almost always come from user error, such as failing to separate liquids properly or not emptying the unit on schedule.

Final Thoughts on the Best Composting Toilets

After testing and researching these 10 models, my top recommendation for most people remains the Nature’s Head Spider Handle. Its proven reliability, massive capacity, and five-year warranty make it the safest investment for full-time off-grid living. For van life specifically, the OGO Origin wins with its electric agitator and tiny footprint.

If you want zero-maintenance simplicity, the Separett Villa eliminates the need for cover material and manual mixing entirely. And for budget-conscious campers, the TRELINO Evo S delivers German engineering at a fraction of the cost of premium models. Finding the best composting toilets for your situation comes down to matching the model to your specific use case, power availability, and maintenance preferences.

Take time to evaluate your installation space, power situation, and how often you are willing to perform maintenance. Any of the 10 models on this list will serve you well when matched to the right application. Here is to going waterless and staying odor-free in 2026.

Leave a Comment