In this TOTO G400 vs G500 comparison, we’ll look at their flushing systems, comfort, cleaning features, water efficiency, pros, cons, and the differences that matter when choosing one for your home.
We’ll also explain whether either model is still worth buying and which newer alternatives deserve your attention.
TOTO G400 vs G500: Features Comparison Chart
Both toilets belong to TOTO’s integrated WASHLET lineup. They combine an elongated toilet bowl with an electronic bidet system instead of requiring homeowners to buy a separate toilet and bidet seat.
Here’s how their main features compare.
| Feature | TOTO G400 | TOTO G500 |
|---|---|---|
| Model Number | MS920CEMFG#01 | MS970CEMFG#01 |
| Approximate Introduction | 2016 | 2012 |
| Toilet Type | Integrated WASHLET toilet | Integrated WASHLET toilet |
| Bowl Shape | Elongated | Elongated |
| Flushing System | 3D Tornado Flush | 3D Tornado Flush |
| Flushing Options | Dual flush | Dual flush |
| Full Flush | 1.28 GPF | 1.28 GPF |
| Reduced Flush | 0.9 GPF | 0.9 GPF |
| PREMIST | Yes | Not included in original G500 specification |
| CEFIONTECT Glaze | Yes | Yes |
| Automatic Flushing | Yes | Yes |
| Auto-Open/Close Lid | Yes | Yes |
| Heated Seat | Yes | Yes |
| Front and Rear Wash | Yes | Yes |
| Warm Air Dryer | Yes | Yes |
| Automatic Deodorizer | Yes | Yes |
| Wireless Remote | Yes | Yes |
| Rough-In | 12 inches | 12 inches |
| Bowl Height | Universal Height | Universal Height |
| WaterSense | Meets WaterSense requirements | Meets WaterSense requirements |
| Availability | Legacy model; verify remaining inventory | Older legacy model; verify remaining inventory |
| Best Advantage | PREMIST and later-generation design | Similar luxury features when available at a suitable price |
| Price |  View Related TOTO WASHLET Listing |
 View Related TOTO Product on Amazon |
As you can see, these toilets have far more similarities than differences. The G400’s PREMIST function is one of its clearest advantages over the original G500.
It’s also important to avoid confusing these models with the later TOTO G450, which uses a different flush-volume configuration.
TOTO G400 WASHLET With Integrated Toilet
The TOTO G400 is a sleek and luxurious toilet that combines modern styling with features usually associated with premium bidet seats.
It was introduced as a later-generation option following the G500, with the addition of PREMIST and other refinements.
Its integrated design is particularly attractive in a modern bathroom. Instead of having a conventional toilet tank with a separate electronic bidet seat, the G400 brings the components together in a compact-looking fixture.
The toilet features an elongated bowl and Universal Height seating, giving users a comfortable position.
The skirted exterior is also easier to wipe clean than a toilet with an exposed trapway.
However, this is still a fairly complex toilet. It requires both plumbing and electrical connections, and installation should follow TOTO’s model-specific instructions.
3D Tornado Flushing System
The G400 uses TOTO’s 3D Tornado Flush system, which directs water around the bowl to help clear waste and rinse the surface.
The dual-flush system provides two options: a reduced 0.9-gallon flush and a full 1.28-gallon flush.
This allows you to choose the appropriate volume for different types of waste.
The G400 also features CEFIONTECT ceramic glaze, which helps reduce the attachment of waste and other debris to the bowl surface.
Combined with PREMIST, the glaze makes routine bowl cleaning more manageable.
However, neither technology makes the toilet completely maintenance-free. Regular cleaning is still necessary.
PREMIST for Easier Bowl Cleaning
PREMIST is one of the biggest reasons to choose the G400 instead of the older G500.
Before use, the system applies a light mist of water to the ceramic bowl.
This helps reduce the chances of waste sticking to the surface.
It’s a useful addition because residue that doesn’t adhere strongly to the bowl is generally easier to rinse away.
Combined with CEFIONTECT, PREMIST can help keep the bowl cleaner between regular cleaning sessions.
Comfort and Convenience
The G400 includes a heated seat with adjustable temperature, making bathroom visits more comfortable in cold weather.
Its warm water cleansing function provides front and rear washing, while the wireless remote lets you adjust water pressure and other settings.
There is also a warm air dryer to reduce the amount of toilet paper needed after washing.
The automatic deodorizer helps control bathroom odors, and the auto-opening lid reduces the need to touch the seat cover.
These features make the G400 attractive to anyone looking for a more hands-free bathroom experience.
For a more detailed breakdown of its features, see our TOTO G400 WASHLET review.
Note: The original Amazon link is retained, but the exact product displayed by the current listing must be checked before it is used as a purchase link for the G400.
TOTO G400 Pros
- PREMIST helps reduce waste sticking to the bowl.
- 3D Tornado Flush provides an efficient dual-flush system.
- CEFIONTECT glaze helps keep the ceramic cleaner.
- Elongated bowl and Universal Height offer comfortable seating.
- Heated seat improves comfort during colder months.
- Automatic opening and closing lid provides convenient operation.
- Warm water cleansing and air drying help reduce toilet paper use.
- Skirted exterior makes routine cleaning easier.
- Built-in deodorizer helps control unwanted odors.
- Automatic flush and wireless remote provide additional convenience.
TOTO G400 Cons
- Costs more than a conventional toilet.
- Requires a compatible electrical outlet.
- Installation is more involved than installing a basic gravity-flush toilet.
- Its complex components may be costly to repair.
- Older-model availability and service support should be checked.
- The warm air dryer may take longer than some users expect.
TOTO G500 WASHLET Integrated Toilet Review
The TOTO G500 helped establish the brand’s integrated WASHLET design as a luxury bathroom option.
It combines a sleek, low-profile appearance with automatic operation and features that make everyday toilet use more comfortable.
Like the G400, the G500 has an elongated bowl, Universal Height, and skirted construction.
It also uses the 3D Tornado Flush system, with full and reduced flush volumes of 1.28 GPF and 0.9 GPF.
This is an important detail because some comparisons incorrectly describe the G500 as having a completely different flushing system.
TOTO’s original G500 specifications identify its flushing technology as 3D Tornado Flush.
Automatic Lid and Hands-Free Flushing
One of the best features of the G500 is its automatic operation.
The lid can open and close automatically, so you don’t have to touch the cover every time you use the toilet.
The G500 also includes automatic flushing. Once the system detects the appropriate user activity, it can flush without the user operating a conventional handle.
These functions improve convenience, although they rely on sensors and electronic components working correctly.
If you’re buying a used G500, be sure to test both the lid mechanism and auto-flush function.
Heated Seat and Bidet Washing
The G500 also provides a heated seat with adjustable temperature.
Its integrated WASHLET includes front and rear warm water cleansing, adjustable water pressure, and spray functions.
A warm air dryer helps with drying after washing, while the deodorizer controls unwanted odors.
These are still appealing features for a luxury toilet, particularly if you’re replacing an older fixture without any bidet functions.
Water Efficiency
The G500’s dual-flush system uses 1.28 gallons for a full flush and 0.9 gallons for a reduced flush.
That means its rated water consumption is the same as the G400 in this comparison.
You shouldn’t choose one over the other expecting a significant difference in their specified flush volumes.
Both were also designed to meet EPA WaterSense efficiency and performance requirements.
The real distinction is in the additional conveniences and the condition of the individual toilet you can purchase.
For a closer look at the original model, visit our TOTO G500 toilet review.
Note: The original G500 affiliate URL is preserved, but the model identity and current availability of the linked product have not been independently confirmed.
TOTO G500 Pros
- Sleek and low-profile design looks attractive in modern bathrooms.
- 3D Tornado Flush with efficient dual-flush volumes.
- Automatic lid opening and closing.
- Hands-free automatic flushing.
- Heated seat with adjustable temperature.
- Warm water front and rear cleansing.
- Wireless remote control.
- Warm air dryer and built-in deodorizer.
- CEFIONTECT ceramic glaze helps reduce buildup.
- Skirted design makes exterior cleaning easier.
TOTO G500 Cons
- Doesn’t include the G400’s PREMIST feature.
- Older model, so availability can be limited.
- Complex electronic components can increase repair costs.
- Requires electricity for electronic WASHLET functions.
- Used units may need replacement seals, filters, or electronic parts.
- Installation can be challenging without professional experience.
Key Differences Between the TOTO G400 and G500
1. PREMIST Function
The biggest practical difference in this comparison is PREMIST.
The G400 includes a function that lightly wets the bowl before use to help keep waste from adhering to the ceramic surface.
The original G500 does not list this function in its specification sheet.
For people who want to minimize stains and make bowl cleaning easier, this gives the G400 a useful advantage.
2. Flushing Performance
Both models use 3D Tornado Flush and have the same 1.28/0.9 GPF flush volumes.
This means there is no reason to claim that one automatically uses less water than the other.
The G400’s PREMIST may improve bowl cleanliness before and during use, but that is different from claiming it has a more powerful flushing system.
Properly maintained versions of either model should be evaluated according to their original performance specifications.
3. Design and Cleaning
Both toilets feature a low-profile integrated design and concealed trapway.
This makes them easier to wipe down than many traditional toilets with exposed curves around the base.
The G400’s PREMIST adds another bowl-maintenance benefit, but both still require routine cleaning.
4. Price and Availability
It would be misleading to say that the G400 is always cheaper or that the G500 always costs more.
Since these are older models, remaining stock and secondhand prices can vary widely.
A well-maintained G500 at a sensible price may offer better value than an expensive G400 with missing accessories or limited support.
On the other hand, if both are available in similar condition and at a similar price, the G400’s additional PREMIST feature makes it the more appealing choice.
5. Installation and Maintenance
Both toilets require careful plumbing and electrical installation.
You’ll need to verify rough-in distance, water supply conditions, electrical access, and sufficient bathroom clearance.
Because these are integrated electronic toilets, repairs can be more complicated than replacing the flapper or fill valve on a conventional toilet.
Before purchasing, confirm that the manufacturer or an authorized service provider can supply the required parts.
You can use our free toilet fit checker to review rough-in and bathroom clearance measurements before ordering.
Are the TOTO G400 and G500 Still Worth Buying?
The G400 and G500 were both premium toilets when introduced, and many of their original features remain useful.
However, buying an older smart toilet is different from buying a conventional toilet with simple replacement parts.
The heated seat, sensor system, remote control, cleansing wand, dryer, and automatic flushing all depend on electronic and mechanical components.
Before purchasing either model, I would check the following:
- Exact model number: Confirm whether the product is MS920CEMFG or MS970CEMFG.
- Condition: Look for damage, leaks, worn controls, or faulty lid operation.
- Parts availability: Verify that replacement components are still obtainable.
- Warranty: Confirm whether remaining-stock purchases qualify for manufacturer coverage.
- Electrical requirements: Ensure the bathroom has a compatible, properly protected outlet.
- Installation fit: Check rough-in, overall projection, and surrounding clearances.
- Seller reputation: Be cautious with listings that show a different model or use outdated product images.
If you cannot confirm these details, buying a newer supported model is generally a safer long-term choice.
Alternative: TOTO G450 Integrated WASHLET Toilet
If you’re interested in the G400 or G500 but would prefer another integrated WASHLET design, the TOTO G450 is worth comparing.
The G450 uses a 1.0 GPF full flush and a 0.8 GPF reduced flush, making it more water-efficient by rated flush volume than the original G400 and G500.
Its features include:
- 1.0/0.8 GPF dual-flush operation.
- TORNADO FLUSH technology.
- CEFIONTECT ceramic glaze.
- PREMIST function.
- Heated seat and warm water cleansing.
- Warm air dryer.
- Automatic air deodorizer.
- Elongated bowl with Universal Height.
- Skirted exterior.
- Remote-controlled WASHLET functions.
These features make the G450 an attractive alternative for buyers looking for greater water efficiency.
However, the G450 is also an older integrated WASHLET generation. You should confirm its availability and current manufacturer support before ordering.
Original related-product link: Check the related TOTO WASHLET listing on Amazon.
Another option is to explore the TOTO NEOREST toilet collection, which includes more advanced integrated models.
Which Is Better: TOTO G400 or G500?
After comparing their features, I would choose the TOTO G400 over the G500 if both were available at a similar price and in comparable condition.
The reason isn’t that the G500 has a weak flush or lacks automatic features. Both models offer 3D Tornado Flush, automatic flushing, heated seats, wireless remotes, and warm water cleansing.
The G400 earns its advantage mainly from the PREMIST feature and its later-generation design.
However, the G500 can still be a good purchase if you find a well-maintained unit at a significantly better price and can confirm replacement-part availability.
For someone remodeling a bathroom today, I would also compare newer integrated WASHLET toilets before spending a large amount on either older model.
Frequently Asked Questions About TOTO G400 vs G500
1. What is the main difference between TOTO G400 and G500?
The G400 includes PREMIST, which wets the toilet bowl before use to help reduce waste sticking to the ceramic surface. Both models offer many of the same premium functions, including automatic flushing, heated seats, and warm water washing.
2. Do the TOTO G400 and G500 use the same flushing system?
Yes. The original manufacturer documentation identifies both models as using 3D Tornado Flush with 1.28 GPF full-flush and 0.9 GPF reduced-flush options.
3. Does the TOTO G500 have automatic flushing?
Yes. The G500 includes automatic flushing and an auto-opening and closing lid. These are not exclusive to the newer G400.
4. Are TOTO G400 and G500 toilets WaterSense certified?
Both models were described by TOTO as meeting WaterSense efficiency and performance standards. Always verify the exact model and any applicable current certification requirements before purchase.
5. Can I replace a TOTO G500 WASHLET unit with a G400 WASHLET unit?
Do not assume the components are interchangeable simply because the toilets look similar. Confirm the exact bowl and WASHLET part numbers with TOTO before attempting a replacement. Electrical connections, mounting points, and control components may differ.
6. Is the TOTO G400 better than the G500?
The G400 has an advantage because of its PREMIST function, but the G500 still offers many premium features. The better purchase depends on the condition, cost, availability, and service support of the exact toilet.
Conclusion
The TOTO G400 and G500 are both luxury integrated WASHLET toilets that provide comfort, convenience, and water-efficient flushing.
Both have elongated bowls, automatic flushing, heated seats, warm water cleansing, and wireless controls.
What sets the G400 apart is its PREMIST feature, which provides an additional way to reduce bowl residue.
So, in this TOTO G400 vs G500 comparison, the G400 is my preferred model when the price and condition are similar.
However, because both are older products, don’t overlook parts availability, warranty support, and current alternatives before making a decision.
A good smart toilet should not only feel luxurious when new but also remain practical to maintain for years to come.
Hi, this is Robert Crossan, the owner of this website, has 17 years of experience in the installation, maintenance, and repair of toilets and plumbing systems. After completing the Level 2 Basic Plumbing course in 2005, I started working in both domestic and commercial buildings as a professional plumber. So I can figure out the core difference between different toilet models and brands. It also helped me monitor their work performance and setbacks.