Choosing between the TOTO C5 and S7 washlets is one of the most common upgrade decisions bidet fans face — and the answer could transform your bathroom routine.
In this breakdown, you’ll get a clear, no-nonsense look at how these two seats compare so you can make the right call for your toilet and lifestyle.
| Feature | TOTO Washlet S5 (C5 Successor) | TOTO Washlet S7 |
|---|---|---|
| Image |  |
 |
| Dimensions (L × W × H) | 21″ × 15-1/16″ × 5.5″ | 20-7/8″ × 15-1/16″ × 4-1/16″ |
| Water Heating | Instantaneous (unlimited) | Instantaneous (unlimited) |
| EWATER+ Coverage | Wand only | Wand + Bowl |
| PREMIST | Yes | Yes |
| User Memory Settings | 4 presets | 4 presets |
| Night Light | Yes | Yes (brighter) |
| Auto Flush Compatible | No | Yes (with kit, select toilets) |
| Buy Now |  |
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1. TOTO Washlet S5 Electronic Bidet Seat (SW3446#01)
The TOTO Washlet S5 is the direct, current-generation replacement for the beloved C5 — and it’s a significant step forward.
Where the C5 relied on a tank heater that could run cold after 30–60 seconds, the S5 delivers unlimited warm water through an instantaneous heating system that never runs out.
Features
- Instantaneous water heater — unlimited warm water from the first second to the last
- PREMIST wets the bowl before use to prevent waste from sticking
- EWATER+ self-cleans the wand inside and out before and after every use
- Wireless remote with 4 user memory presets
- Five spray settings including oscillating and pulsating modes
- Heated SoftClose seat with five temperature settings
- Warm air dryer and automatic air deodorizer
- Built-in night light for easy nighttime navigation
- Seamless seat design — no gap where dirt can collect
- Fits most standard elongated toilets; easy DIY installation
Pros
- Unlimited warm water is a game-changer over the old C5 tank heater
- Slimmer profile than the C5 at 5.5″ rear height
- Four user presets make it ideal for multi-person households
- More affordable entry point into TOTO’s premium S-series lineup
- Night light and seamless seat are notable upgrades from its predecessor
Cons
- EWATER+ only covers the wand, not the bowl (that’s the S7’s territory)
- No auto-flush compatibility
- Slightly taller rear profile than the S7 (5.5″ vs 4.1″)
If you loved the C5 but wanted unlimited hot water and a more modern look, the S5 delivers everything you were waiting for — and then some.
If you’re also weighing it against other top-rated options, check out our bidet toilet seat comparison chart for a broader side-by-side look at the market.
Check its current price on Amazon
2. TOTO Washlet S7 Electronic Bidet Seat (SW4726AT40#01)
The TOTO Washlet S7 is TOTO’s current flagship bidet seat — the most refined, most feature-complete model in the lineup short of the auto-open S7A.
It replaces the S500e with a sleeker silhouette, a redesigned contemporary lid that sits flush with the bowl, and critical hygiene upgrades including EWATER+ coverage for both the wand and the toilet bowl.
Features
- Instantaneous water heater — continuous, unlimited warm water
- EWATER+ cleans both the wand and the bowl before and after every use
- PREMIST bowls the bowl before each use
- Wide-front cleaning option for more comprehensive feminine wash
- Wireless remote with 4 user memory presets
- Five spray settings with oscillating and pulsating modes
- Heated SoftClose seat and warm air dryer
- Upgraded, brighter night light
- Ultra-slim rear profile at just 4.1″ — one of the slimmest seats available
- Contemporary lid design sits flush with the bowl for an integrated look
- Auto-flush compatible with separately sold kit on select TOTO T40 toilets
Pros
- Bowl EWATER+ misting adds a whole layer of hands-free hygiene the S5 skips
- Slimmest profile in the lineup at 4.1″ — noticeably sleeker than the S5
- Contemporary lid design gives a near-integrated look even on non-TOTO toilets
- Wide-front cleaning is a genuine comfort upgrade
- Auto-flush kit compatibility is a major convenience for the right setup
Cons
- Significantly higher price point than the S5
- WASHLET+ cord-concealment feature only works with compatible TOTO toilets
- Auto-flush kit sold separately and limited to T40 WASHLET+ ready toilets
The S7 is the seat for buyers who want total bathroom hygiene automation and a look that rivals an integrated unit — without having to buy a whole new toilet.
For even more options at the premium end, our guide to the highest-rated bidet toilets covers integrated smart toilet alternatives worth considering.
Check its current price on Amazon
Head-to-Head: Water Heating
Both seats use an instantaneous water heater, which is one of the biggest upgrades from the old C5.
The C5 used a tank heater, meaning warm water would run out after roughly 30 to 60 seconds — a frustrating limitation for thorough cleansing.
The S5 and S7 both solve this completely.
You get continuous warm water from start to finish, no matter how long your wash takes.
This single upgrade alone is a major reason anyone still using a C5 should consider transitioning to the S5 or S7.
If you’re comparing the hot water experience of different bidet types, our article on the best bidets with dryers also covers how warm air drying stacks up across brands.
Head-to-Head: Hygiene and EWATER+ Coverage
This is where the S7 pulls meaningfully ahead of the S5.
Both seats use PREMIST to wet the bowl before each use, helping prevent waste from sticking to the ceramic.
Both also use EWATER+ to clean the wand after every use.
But the S7 goes a step further — it also mists the inside of the bowl with EWATER+ electrolyzed water after you leave, providing a level of passive, chemical-free bowl cleaning that the S5 simply doesn’t offer.
If keeping your toilet bowl cleaner between scrubs matters to you — and it should — the S7 delivers it automatically.
For more detail on how self-cleaning bidet technology works, our guide to the best self-cleaning bidets is a great companion read.
Head-to-Head: Design and Profile
The S7 is noticeably slimmer.
At 4.1 inches in rear height versus the S5’s 5.5 inches, the S7 sits lower on the bowl, creating a more integrated, modern look — especially when paired with a TOTO WASHLET+ compatible toilet that conceals the power cord and water line.
The S7’s contemporary lid is designed to sit flush with the toilet bowl, giving the impression of a fully integrated bidet toilet even when it’s just a seat.
The S5 looks great too — much slimmer than the old C5 — but the S7 has a clear aesthetic edge in bathrooms where appearance matters.
If you’re designing a full bathroom upgrade, also take a look at our best toilets with bidet roundup for integrated combo options.
Head-to-Head: User Convenience
Both seats offer a wireless remote with four user memory presets, five spray settings, oscillating and pulsating modes, a heated seat, warm air dryer, air deodorizer, and a night light.
The S7 edges ahead with a brighter night light, a wide-front cleaning setting for enhanced feminine wash, and auto-flush compatibility via a separately sold kit on select TOTO toilets.
The S5 has no auto-flush support, and while its night light is functional, the S7’s is notably brighter.
For multi-user households where everyone wants their settings saved and ready, both seats are equally equipped with four memory presets — check out our best heated bidet toilet seats guide if seat warmth is your top priority in a shared bathroom.
Head-to-Head: Installation and Compatibility
Both seats are designed for DIY installation on most standard elongated toilets.
You attach the seat to the bowl, connect a T-connector to your toilet’s water supply line, and plug the unit into a nearby GFCI outlet.
Both are also WASHLET+ compatible, meaning you can use them with TOTO WASHLET+ ready toilets to conceal the power cord and water supply hose for a clean, cable-free look.
The S7 adds the option of auto-flush integration when used with a separately sold kit and a compatible TOTO T40 WASHLET+ ready toilet — the S5 has no equivalent option.
If you’re buying your first bidet seat, our guide to the best bidets for existing toilets walks through what to check before you buy.
Verdict — Which One Should You Buy?
Buy the TOTO Washlet S5 if… you’re upgrading from the C5 (or a similar tank-heater seat) and you want the best balance of features, value, and TOTO reliability without paying the premium for bowl EWATER+ and auto-flush compatibility.
The S5 gives you everything the C5 lacked — unlimited warm water, a night light, a seamless seat, and four user presets — at a more accessible price point.
It’s the smart upgrade for most households, and it earns the Wirecutter’s endorsement as the best bidet seat on the market.
Buy the TOTO Washlet S7 if… you want TOTO’s best non-auto-open seat, with EWATER+ bowl cleaning, a strikingly slim 4.1″ profile, wide-front wash, and auto-flush capability on compatible TOTO setups.
If your bathroom’s appearance matters and you want passive bowl hygiene without scrubbing, the S7 justifies its premium.
It’s the right pick for design-forward buyers and hygiene-obsessed households who won’t settle for second-best.
For a broader look at where these seats sit in the overall market, see our best bidets for home use roundup.
FAQ
Is the TOTO C5 still available?
The TOTO C5 has been discontinued as of 2025.
TOTO is actively transitioning dealers from the C-series to the newer S-series.
The direct replacement for the C5 is the TOTO Washlet S5, which shares the same core functionality but upgrades to an instantaneous water heater, adds a night light, four user presets, and a seamless seat design.
If you were comparing the original C5 and S7, comparing the current S5 vs S7 is the most accurate and relevant frame for making a purchase decision today.
What is the main difference between the S5 and S7?
The two biggest differences are EWATER+ bowl coverage and overall profile height.
The S7 adds automatic EWATER+ misting inside the toilet bowl after every use — the S5 only cleans the wand.
The S7 is also significantly slimmer at 4.1″ versus the S5’s 5.5″ rear height, and includes a wide-front cleaning option and auto-flush compatibility.
Do both the S5 and S7 work on non-TOTO toilets?
Yes — both seats are compatible with most standard elongated toilet bowls from any manufacturer.
The WASHLET+ cord-concealment feature only activates on TOTO WASHLET+ ready toilets, but the core bidet functions work on virtually any elongated bowl.
Always confirm your toilet has at least 2 inches of flat clearance behind the mounting holes before purchasing.
Can I install either seat myself?
Both seats are designed for straightforward DIY installation — no plumber required.
You’ll need a nearby GFCI outlet, as both seats require a 120V connection.
The process involves attaching the base plate, connecting a T-connector to your water supply line, and plugging the unit in.
Most installations take under an hour.
For tips on installation and choosing the right bidet for your setup, our guide to bidets for existing toilets is a helpful starting point.
Conclusion
When you stack the TOTO C5 vs S7 — or more accurately, the current S5 against the S7 — the right choice comes down to what you value most.
The TOTO Washlet S5 is the smarter value pick: unlimited hot water, four user presets, a night light, and a seamless seat for less money.
The TOTO Washlet S7 is the premium pick: slimmer profile, bowl EWATER+, wide-front wash, and auto-flush compatibility for buyers who want the best without going fully integrated.
Either way, you’re getting TOTO’s world-class washlet engineering — a genuine upgrade from any tank-heater seat.
If you want to keep exploring your options, check out our full bidet toilet seat comparison chart or browse the best bidets for home use to find the perfect fit for your bathroom.
