If you’re deciding between the TOTO WASHLET KS6 and KS5, you’re comparing two of TOTO’s newest online-exclusive bidet seats — and the difference is bigger than you might expect.
This breakdown gives you everything you need so you can pick the right one for your bathroom.
| Feature | TOTO WASHLET KS6 (SW3946) | TOTO WASHLET KS5 (SW3216) |
|---|---|---|
| Image |  |
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| Dimensions (L x W x H) | 25-5/16″ x 15-1/4″ x 11-13/16″ | ~24.6″ x 15.3″ x similar profile |
| Water Heating | Instantaneous (tankless) | Instantaneous (tankless) |
| EWATER+ Wand Cleaning | ✅ Yes | ❌ No (standard auto-rinse) |
| PREMIST Bowl Misting | ✅ Yes | ❌ No |
| Auto Deodorizer | ✅ Yes | ❌ No |
| User Presets | 4 users | 4 users |
| Heated Seat / Warm Air Dryer | ✅ 5 levels each | ✅ 5 levels each |
| Buy Now |  |
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1. TOTO WASHLET KS6 (SW3946#01)
The TOTO WASHLET KS6 is TOTO’s most feature-complete online-exclusive bidet seat, packing the brand’s full hygiene suite into a sleek, sculpted silhouette.
It replaces the popular K300 and brings EWATER+, PREMIST, and an automatic deodorizer — features you’d normally expect at a higher price point — into a slim, modern package.
Features
- Instantaneous tankless water heating — unlimited warm water from the first second
- EWATER+ electrolyzed water wand cleaning before and after every use
- PREMIST automatically mists the bowl before each use to reduce waste adhesion
- Automatic air deodorizer neutralizes odors in real time
- 5 spray settings: rear, soft rear, front, oscillating, and pulsating
- Heated seat with 5 temperature levels and auto-sensing activation
- Warm air dryer with 5 adjustable heat levels
- Auto-sensing LED night light
- Illuminated wireless remote with 4 user memory presets (wall-mountable)
- SoftClose lid, CLEAN RESIN seamless seat design
- WASHLET+ compatible for concealed connections
Pros
- Full TOTO hygiene suite: EWATER+, PREMIST, and deodorizer all included
- Slim, sculpted profile gives a modern, integrated look
- 4 user presets make it ideal for households with multiple users
- Illuminated remote is easy to use day or night
- Replaces K300 with meaningfully better hygiene tech
Cons
- Available in elongated size and Cotton White only — no color or shape flexibility
- Online exclusive: no showroom option for hands-on preview
- Requires at least 2″ of flat space behind the seat mounting holes
If you want TOTO’s full hygiene arsenal — EWATER+, PREMIST, and auto deodorizer — in a refined, low-profile package, the KS6 is the definitive choice in this lineup.
It’s the seat you buy when you want the bowl and the wand handled automatically, every single time, without lifting a finger.
Check its current price on Amazon
2. TOTO WASHLET KS5 (SW3216#01)
The TOTO WASHLET KS5 is the more budget-accessible entry in TOTO’s new online-exclusive KS lineup, delivering the core WASHLET experience — tankless warm water, a heated seat, and a remote with user presets — at a lower price.
It skips EWATER+, PREMIST, and the automatic deodorizer compared to the KS6, but it still delivers all the comfort features most daily users care about most.
Features
- Instantaneous tankless water heating — no waiting, no running cold
- Front and rear wash with oscillating and pulsating spray options
- Heated seat with 5 temperature levels and auto-sensing activation
- Warm air dryer with 5 adjustable heat levels
- Auto-sensing LED night light
- Illuminated wireless remote with 4 user memory presets (wall-mountable)
- Standard auto-rinse wand self-cleaning
- SoftClose lid, CLEAN RESIN seamless seat design
- WASHLET+ compatible for concealed connections
Pros
- Meaningfully lower price than the KS6 while keeping the core comfort experience
- Tankless water heating gives you endless warm water — same as the KS6
- 4 user presets — same family-friendly capacity as the premium model
- WASHLET+ compatible, great for pairing with a TOTO toilet later
- Reliable entry point into TOTO’s new KS lineup
Cons
- No EWATER+ — wand cleaning relies on standard auto-rinse only
- No PREMIST — your bowl doesn’t get pre-misted before use
- No automatic deodorizer — odor control isn’t built in
- More traditional, slightly taller profile compared to the KS6’s slimmer look
- Elongated, Cotton White only — same limited availability as the KS6
The KS5 makes the most sense if you want TOTO’s reliability and tankless warm water comfort, but you’re willing to manage your bowl hygiene manually and don’t need automatic odor control.
For households where budget matters more than hygiene automation, this is a genuinely smart pick.
Check its current price on Amazon
Hygiene Technology: EWATER+ and PREMIST
This is the single most important difference between the two seats, and it’s bigger than it looks on paper.
The KS6 comes with EWATER+, which transforms ordinary water into a sanitizing electrolyzed compound that automatically cleans the wand inside and out before and after every single use.
It also uses PREMIST to spray the toilet bowl with water before you sit down, creating a slick surface that dramatically reduces how much waste sticks to the ceramic.
The KS5 has neither.
It uses a standard auto-rinse for the wand, which rinses but doesn’t sanitize the way EWATER+ does.
If you want a bowl and wand that clean themselves automatically — the kind of passive, chemical-free hygiene you’d expect from a premium bidet — only the KS6 delivers it.
You can read more about how TOTO’s hygiene technology stacks up across the full lineup in our bidet toilet seat comparison chart.
Winner: TOTO WASHLET KS6
Comfort Features: Warm Water, Heated Seat, and Dryer
Here’s where the two seats are essentially identical — and that’s a meaningful point in the KS5’s favor.
Both models use instantaneous tankless water heating, which means you get warm water from the very first second of every wash cycle, for as long as you need it.
That’s the same system found on higher-end models like the TOTO Washlet S5, and it completely eliminates the “cold blast” issue that plagued older tank-style seats.
Both seats have a 5-level heated seat with auto-sensing activation — the seat begins warming as you approach, not after you sit down.
Both offer a warm air dryer with 5 heat levels, which lets you reduce or eliminate toilet paper entirely.
If your main concerns are warm water comfort and a cozy seat in winter, the KS5 gives you everything the KS6 has in this category.
For more on the warm water experience across different bidet types, check out our guide to the best bidets for existing toilets.
Winner: Tie — both deliver the same comfort experience
Design and Profile
The KS6 has a noticeably slimmer, more sculpted modern silhouette compared to the KS5’s slightly taller, more traditional shape.
In practice, both will fit most standard elongated toilets — but the KS6’s lower profile gives it a more integrated, built-in look that pairs especially well with contemporary bathroom designs.
The KS5’s more traditional rear profile is perfectly functional and won’t look out of place, but it does sit a bit higher at the back than the KS6.
Both require at least 2″ of flat space between the toilet tank and the seat mounting holes, and both are WASHLET+ compatible for a concealed-connection install.
Neither model offers auto-open or auto-close lid functionality — for that, you’d need to step up to the TOTO Washlet S7 or S7A.
If your bathroom leans modern and appearance matters to you, the KS6’s slimmer aesthetic edges ahead.
Winner: TOTO WASHLET KS6 — slimmer and more modern-looking
Controls and User Presets
Both the KS5 and KS6 come with an illuminated wireless remote that can be held in hand or mounted to the wall.
Both store 4 user memory presets, which is one of the key improvements over the older K300 and makes these seats genuinely practical for multi-person households.
For families where everyone wants their own saved settings for water temperature, pressure, nozzle position, and seat warmth, four presets gives you meaningful flexibility.
The controls are virtually identical across both models, so this category is a genuine tie.
If you want to explore how user preset systems compare across bidet brands, our guide to the best heated bidet toilet seats covers this in detail.
Winner: Tie — both have 4-user illuminated remotes
Verdict — Which One Should You Buy?
Both seats are excellent TOTO products, and both deliver the tankless warm water experience that makes these new KS-series seats worth considering.
But the right pick depends on what you’re willing to trade.
Buy the TOTO WASHLET KS6 if…
- You want EWATER+, PREMIST, and automatic deodorizer — TOTO’s full hygiene suite
- You want the slimmer, more modern-looking profile in your bathroom
- You want the bowl and wand to clean themselves with zero effort from you
- You’re replacing a K300 and want a clear, meaningful upgrade
- You’re buying a premium bidet and want to future-proof the purchase
Buy the TOTO WASHLET KS5 if…
- Budget is your primary constraint and you want to save meaningfully on the purchase
- You’re fine cleaning the bowl manually and don’t need wand sanitization via EWATER+
- You want tankless warm water and all comfort features without paying for the hygiene extras
- You’re a first-time TOTO buyer who wants to experience the brand at a lower entry point
- You don’t need an automatic deodorizer in your bathroom setup
If hygiene automation matters to you — and for most households, it should — the KS6 is worth the extra cost.
The KS5 is a solid seat, but it’s really the choice you make when the price difference is a deciding factor, not the feature list.
FAQ
Is the TOTO KS5 the same as the K300?
No — the KS5 is a newer model that replaces the K300 alongside the KS6.
The KS5 shares the K300’s core comfort features (tankless heating, remote, heated seat) but improves on fit and design.
Unlike the K300, the KS5 does not include EWATER+ or PREMIST — those are reserved for the KS6 in this lineup.
If you want the hygiene features the K300 offered, the KS6 is the more accurate successor.
What’s the main difference between the KS6 and KS5?
The three biggest differences are EWATER+ wand sanitization, PREMIST bowl misting, and the automatic deodorizer — all present on the KS6 and absent on the KS5.
The KS6 also has a slimmer, more modern profile.
All comfort features — tankless water heating, heated seat, warm air dryer, night light, and 4-user remote — are identical across both models.
You can see how these compare against the broader TOTO lineup in our bidet toilet seat comparison chart.
Are the KS5 and KS6 compatible with round toilets?
No — both the KS5 and KS6 are designed for elongated toilet bowls only and are available in Cotton White only.
If you have a round toilet or need a different color finish, you’ll want to look at other models in the TOTO lineup such as the TOTO S2, which offers both round and elongated versions.
Always measure your toilet bowl before purchasing to confirm the seat will fit correctly — our guide to the best bidets for existing toilets covers how to do this.
Can I install the KS5 or KS6 myself?
Yes — both seats are designed for DIY installation and come with all necessary hardware.
You’ll need a standard elongated toilet, a GFCI-protected outlet within reach (the power cord is approximately 3.9 ft long), and at least 2″ of flat space between the toilet tank and the seat mounting holes.
TOTO also supports the BILT Intelligent Instructions app for interactive 3D installation guidance.
Most users complete the install in under an hour without a plumber.
Conclusion
The TOTO KS6 and KS5 sit closer together than almost any other comparison in the bidet market — same heating system, same remote, same presets, same dryer.
But the KS6’s EWATER+, PREMIST, and auto deodorizer create a meaningful gap in passive hygiene that’s hard to ignore once you understand what those features actually do day-to-day.
If budget is tight, the KS5 is a legitimate TOTO product that delivers excellent warm water comfort — and it’s a genuinely better seat than most of what’s available at its price point.
But if you’re buying a premium bidet seat and want it to handle bowl and wand hygiene automatically for years to come, spend the extra on the KS6.
Still comparing your options?
Our bidet seat comparison chart covers the full market side by side, and our guide to the best bidets for home use can help you decide whether a TOTO seat is the right direction for your bathroom at all.
