The TOTO Washlet S5 is the brand’s newest mid-range flagship — and it replaces the beloved C5 with unlimited warm water, a slimmer profile, and TOTO’s signature hygiene technology that no other seat quite matches.
If you’ve been on the fence about upgrading your bathroom, this review will tell you everything you need to know before you decide.
| Specification | Detail |
|---|---|
| Image |  |
| Model Number | SW3446#01 (Elongated) / SW3445#01 (Round) |
| Dimensions (L x W x H) | ~20.5″ x 15″ x 5.5″ |
| Water Heating | Instantaneous tankless (unlimited warm water) |
| Wash Modes | Rear cleanse, rear soft, front cleanse, oscillating, pulsating |
| Hygiene Tech | EWATER+, PREMIST, CLEAN RESIN |
| User Presets | 4 memory settings |
| Heated Seat | Yes — 5 temperature levels |
| Warm Air Dryer | Yes — 5 temperature levels |
| Night Light | Yes |
| Remote Control | Wireless with wall-mount docking station |
| Colors Available | Cotton White, Sedona Beige |
| Toilet Compatibility | Elongated and Round |
| Warranty | 1-year limited |
| Buy Now |  |
| ✅ Pros | ❌ Cons |
|---|---|
| Unlimited warm water — never runs cold mid-wash | Only a 1-year warranty (short for the price) |
| PREMIST keeps the bowl cleaner with zero extra effort | No auto open/close lid |
| EWATER+ sterilizes the wand with electrolyzed water | Elongated-only for the standard model (round sold separately) |
| 4 user memory presets — ideal for households with multiple users | Spray pressure is gentler than some competitors |
| 19% slimmer than the old C5 — sleek modern look | Remote cradle requires wall mounting for best experience |
| Named Wirecutter’s Best Bidet Seat of 2025 | No UV sterilization (unlike some rival seats) |
| Energy-saving auto mode reduces power consumption by up to 38% | Power cord only 3.93 ft — outlet must be nearby |
Check its current price on Amazon.
Is the TOTO Washlet S5 Worth It?
Yes — without question, and especially at its current price point.
The S5 is TOTO’s sweet spot: it sits above the entry-level S2 in features and below the flagship S7 in price, making it the most well-rounded WASHLET you can buy for everyday home use.
It earned Wirecutter’s Best Bidet Seat of 2025 title, and after looking at what it brings to the table, that’s not hard to understand.
The combination of PREMIST, EWATER+, and instantaneous water heating is something no bidet seat at this level from any other brand can replicate — and those three technologies alone make the S5 one of the best bidets for existing toilets available today.
Design and Build Quality
The first thing you’ll notice about the S5 is how clean it looks on the toilet.
At 19% slimmer than its predecessor the C5, it sits lower and feels more integrated — less like an add-on, more like it belongs there.
The seamless seat design is a particular standout: there’s no gap between the seat and the lid where grime can collect, which makes cleaning genuinely easier than older bidet seat designs.
TOTO’s CLEAN RESIN technology on the wand and seat surface adds another layer of protection, repelling dirt and waste at a molecular level so the seat stays hygienic with minimal upkeep.
It’s available in Cotton White and Sedona Beige — if you’re unsure which shade matches your toilet, our guide on TOTO Colonial White vs Cotton White covers exactly how to tell them apart.
Cleaning Performance
This is where the S5 truly separates itself from the competition.
PREMIST automatically mists the inside of the toilet bowl with water before you sit down, which prevents waste from sticking to the porcelain.
The result: a cleaner bowl between scrubs, and noticeably less time spent with a toilet brush.
Once you sit, the instantaneous tankless water heater kicks in and delivers warm water from the very first second — no waiting, no warm-up period, and no cold shock mid-wash like you might experience with a tank-heated seat.
The wand itself cleans inside and out using EWATER+ — electrolyzed water that transforms regular tap water into a mild sterilizing agent — before and after every single use.
This is TOTO’s signature hygiene system, and it puts the S5 in a completely different league from seats that rely only on a water rinse for nozzle cleaning.
Wash options include rear cleanse, rear soft cleanse, front cleanse, plus oscillating and pulsating modes — five spray configurations in total, all adjustable in position, pressure, and temperature.
The spray is gentle and precise, which longtime TOTO fans will recognize as the brand’s philosophy: thorough and comfortable rather than forceful.
If you’ve been comparing this to other options in the bidet seat comparison chart, the hygiene story here is genuinely hard to beat.
Comfort Features
The heated SoftClose seat has five temperature settings ranging from 82°F to 97°F, so you can dial in exactly the right level of warmth for any season.
The warm air dryer also has five temperature levels going all the way up to 140°F — enough airflow to actually finish the job without reaching for toilet paper, which is the whole point.
The night light illuminates the inside of the bowl in a soft glow that makes late-night trips to the bathroom much easier to navigate without turning on the lights and waking yourself up fully.
The auto energy-saver mode is a thoughtful addition too: it monitors usage patterns and adjusts the seat temperature automatically during low-use periods, cutting energy consumption by up to 38% compared to the C5.
For households with multiple users, the four memory presets on the wireless remote let every person in the family save their preferred settings and recall them instantly — a feature that makes a real practical difference if you’ve ever shared a bidet and had to reset it every time.
This makes it a particularly excellent option for seniors and anyone who benefits from a consistent, personalized setup every time they use the bathroom.
Remote Control and Installation
The S5 comes with a slim wireless remote that sits in a wall-mount docking cradle — a significant upgrade from having it just sit loose on the toilet tank.
The remote is well-organized with clearly labeled buttons on both sides: basic functions on the front, fine-tuning controls on the back.
Installation is fully DIY-friendly and should take most people under 30 minutes.
You attach the mounting plate to the toilet’s existing bolt holes, connect the water T-valve to the supply line, and plug the seat into a standard GFCI outlet.
The power cord is 3.93 feet long, so make sure your outlet is close — if it isn’t, that’s the one potential snag worth planning for before you buy.
The S5 is also WASHLET+ compatible, meaning it can be paired with compatible TOTO toilets to conceal the power cord and water supply line behind the toilet for a completely clean, cable-free look.
Who Is the TOTO Washlet S5 Best For?
The S5 is the right seat for you if you want TOTO’s best-in-class hygiene technology — specifically PREMIST and EWATER+ — without stepping all the way up to the premium S7.
It’s ideal for multi-person households thanks to four user presets, and it’s a standout choice for anyone upgrading from the old C5 who wants unlimited warm water and a more modern design.
It’s also worth considering if you care about energy efficiency, since the S5 uses meaningfully less power than its predecessor while delivering a better experience.
If you’re deciding between this and the step-up model, our detailed TOTO C5 vs S7 comparison covers exactly when paying more is worth it — and when it isn’t.
For a head-to-head against the top competitor at this level, our Brondell Swash 1400 vs TOTO Washlet S5 breakdown is also worth a read before you decide.
FAQ
Is the TOTO Washlet S5 the replacement for the C5?
Yes.
The S5 is TOTO’s official successor to the C5, which has been discontinued.
The S5 is an upgrade in nearly every meaningful way: instantaneous water heating instead of a tank, a slimmer profile, four user presets instead of two, an updated remote with wall dock, and up to 38% better energy efficiency.
If you were considering a C5, the S5 is the current version to buy.
Does the TOTO Washlet S5 fit round toilets?
Yes — but you need a different model number.
The SW3446#01 reviewed here is elongated only.
For round toilets, look for the SW3445#01, which has the same features in a round-fit configuration.
Always measure your toilet bowl before purchasing any bidet for home use to confirm the shape.
What is PREMIST and does it actually make a difference?
PREMIST is a TOTO technology that automatically sprays a fine mist of water on the inside of the toilet bowl before each use.
This coating of water prevents waste from adhering to the porcelain, which results in a cleaner bowl and less frequent scrubbing.
In everyday use, the difference is very noticeable — the bowl simply stays cleaner between cleans than it does with a regular toilet or a standard bidet seat that lacks this feature.
How does the TOTO S5 compare to the S7?
The S7 is TOTO’s flagship seat and steps up the S5 with EWATER+ bowl cleaning (not just wand cleaning), a lower 4.1″ rear profile, auto-flush compatibility, and a contemporary lid design that sits flush with the bowl.
The S5 handles wand cleaning with EWATER+ but does not clean the bowl with it — PREMIST handles bowl hygiene instead.
For most buyers, the S5 hits the sweet spot of features and value.
For a full breakdown of what justifies the premium, see our TOTO C5 vs S7 comparison.
Conclusion
The TOTO Washlet S5 is one of the most thoughtfully engineered bidet seats on the market, and Wirecutter’s Best Bidet Seat of 2025 designation is thoroughly deserved.
PREMIST, EWATER+, unlimited warm water, four user presets, and a genuine focus on long-term hygiene set it apart from almost everything else at its price point.
The 1-year warranty is the one area where TOTO leaves room for improvement — brands like Brondell and Bio Bidet offer longer coverage — but the build quality and reputation for reliability go a long way toward offsetting that concern.
If you’ve been comparing the pros and cons of switching to a bidet and the S5 fits your toilet and budget, it’s one of the safest and most satisfying purchases you can make for your bathroom.
For anyone who wants to see how it stacks up against the full field before deciding, our bidet seat comparison chart and best bidets for existing toilets guide are the best next stops.
