If you’re choosing between TOTO’s newest WASHLET seats, the S2 vs S5 comparison comes down to one key question.
Do you want a clean, reliable side panel — or a wireless remote with personalized presets for your whole household?
| Feature | TOTO WASHLET S2 | TOTO WASHLET S5 |
|---|---|---|
| Image |  |
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| Model | SW3346#01 | SW3446#01 |
| Water Heating | Instantaneous (tankless) | Instantaneous (tankless) |
| Controls | Side arm panel | Wireless remote |
| User Presets | None | 4 user presets |
| Night Light | Yes | Yes |
| Dimensions (Elongated) | 20.1″ x 14.6″ x 5.5″ | 20.2″ x 14.6″ x 5.5″ |
| EWATER+ / PREMIST | Both included | Both included |
| Buy Now |  |
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1. TOTO WASHLET S2 Electronic Bidet Seat (SW3346)
The TOTO WASHLET S2 is the direct successor to the discontinued C2, and it brings a significant upgrade to the table right away.
Gone is the tank-based water heater — the S2 now uses an instantaneous ceramic heater that delivers unlimited warm water from the very first second you use it.
It’s a cleaner, slimmer seat with a no-fuss side arm panel that puts all the controls right at your fingertips.
Features
- Instantaneous water heating — unlimited warm water, no tank, no cold surprises
- PREMIST sprays the bowl before every use to prevent waste adhesion
- EWATER+ electrolyzed water automatically cleans the wand inside and out after each use
- Adjustable front and rear cleanse with oscillating spray option
- Heated SoftClose seat with three temperature settings
- Warm air dryer with three temperature settings
- Auto air deodorizer with powerful filters
- Built-in night light for easy nighttime navigation
- Side arm control panel with clearly labeled buttons
Pros
- Excellent value — delivers true TOTO quality at the more accessible price point in the S-series
- Tankless design means the seat profile is noticeably slimmer than older C-series models
- EWATER+ and PREMIST keep both the wand and the bowl passively clean with zero effort from you
- Unlimited warm water is a genuine upgrade over the tank system it replaced
- Simple side panel is very intuitive — great for households where fuss-free controls are preferred
Cons
- No wireless remote — all adjustments are made manually each session via the side panel
- No user preset memory — you’ll re-dial your preferred settings each time
- Side arm panel adds a small visual element to the seat that some find less streamlined
The S2 is the right pick if you want everything that makes a TOTO WASHLET great — endless warm water, self-cleaning EWATER+ technology, PREMIST bowl hygiene — without the added cost of remote-based personalization.
If you already know what settings you like and live alone or with one other person, you’ll probably never miss the remote.
It’s also a great first WASHLET for anyone upgrading from a basic bidet for an existing toilet who wants to step up to a full-featured electronic seat.
Check its current price on Amazon
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2. TOTO WASHLET S5 Electronic Bidet Seat (SW3446)
The TOTO WASHLET S5 takes everything the S2 offers and adds the one feature that makes the biggest difference in a shared bathroom: a wireless remote with four programmable user presets.
It’s the direct upgrade to the discontinued C5 — and it’s a meaningful improvement, not just a name change.
The S5 includes an illuminated touchpad remote that can be wall-mounted next to the toilet for true hands-free convenience.
Features
- Wireless remote with illuminated touchpad — can be wall-mounted for easy access
- 4 user preset memory slots — each person in the household saves their own settings
- Instantaneous ceramic water heater — unlimited warm water on demand
- PREMIST bowl preparation before every use
- EWATER+ wand cleaning with electrolyzed water after every use
- Adjustable front and rear cleanse with oscillating and pulsating spray modes
- Heated SoftClose seat with five temperature settings
- Warm air dryer with five temperature settings
- Auto air deodorizer
- Night light that gently illuminates the bowl
- Auto energy-saver mode adjusts seat temperature when inactive
- Seamless, panel-free seat design for easy cleaning
Pros
- Wireless remote is genuinely more comfortable to use — especially helpful for anyone with limited mobility
- Four user presets mean every member of the household has their perfect settings stored and ready
- Panel-free seat design is cleaner, more modern, and easier to wipe down
- Five temperature settings on both the seat and dryer offer more fine-tuned comfort than the S2’s three
- Auto energy saver mode helps reduce electricity usage without any manual effort
Cons
- Higher price than the S2 — the remote and presets do come at a cost
- Remote needs to be placed or mounted somewhere accessible — one more thing to manage in the bathroom
- For a solo user with fixed preferences, the presets may feel like a feature you paid for but don’t need
The S5 is the seat that makes the most sense for families or anyone who shares a bathroom.
Once you’ve used a seat where your perfect settings are one button press away, going back to manually adjusting the panel every time feels like a step backward.
It’s also a strong pick if you care about a minimal, clean aesthetic in your bathroom — without a side arm panel, the S5 simply looks more integrated and modern.
If you’re already familiar with bidets for home use and want to move up to a premium experience, this is the TOTO to get.
Check its current price on Amazon
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Controls: S2 Side Panel vs S5 Remote
This is the defining difference between the two seats — and it’s worth thinking about carefully.
The S2’s side arm panel keeps everything physically attached to the seat.
You can see the buttons, press them directly, and adjust settings by hand while seated.
It’s intuitive, reliable, and removes any question of where the remote is.
The S5’s wireless remote gives you the ability to adjust everything before you even sit down.
The illuminated touchpad is easy to read in the dark, and the wall-mount option means it’s always in the same spot.
For people with mobility limitations or who simply prefer not to reach over to the seat, the remote is a meaningful upgrade in day-to-day comfort.
Winner: S5 — the remote is more convenient for most people, and the wall mount eliminates the “where did I leave it” problem entirely.
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Water Performance: Are They Actually Different?
Here’s the honest answer — no, they’re not.
Both the S2 and S5 use the exact same instantaneous ceramic water heater.
Both deliver unlimited warm water at the same temperature range and the same five adjustable pressure settings.
Both use the same EWATER+ wand cleaning system and the same PREMIST bowl preparation technology.
The cleansing experience on either seat is genuinely excellent and identical in performance.
This is important to know because some buyers assume the more expensive S5 sprays better.
It doesn’t — and that’s not a criticism.
It means you get the same class-leading TOTO cleaning on both seats.
If you’ve ever had to deal with getting left wet after a bidet, the warm air dryer on both seats handles that cleanly — though the S5 gives you five dryer temperature levels versus the S2’s three.
Winner: Tie — identical core water performance on both seats.
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Hygiene Technology: EWATER+ and PREMIST
Both seats share TOTO’s best passive hygiene features, and they’re worth understanding.
PREMIST activates automatically before every use, spraying the bowl with water so waste doesn’t stick to the ceramic.
That single feature dramatically reduces how often you need to scrub the bowl.
EWATER+ takes electrolyzed water — regular tap water that’s been transformed into a mild sanitizing compound — and uses it to mist both the inside and outside of the wand before and after every use.
The wand cleans itself.
You don’t have to do it.
This is one of the reasons TOTO WASHLET seats are popular among people learning how bidets work for the first time — the hygiene is genuinely hands-off.
Winner: Tie — both seats are equally equipped with TOTO’s full hygiene suite.
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Design and Bathroom Aesthetics
Both the S2 and S5 are part of TOTO’s new S-series, which is approximately 19% slimmer than the C-series they replaced.
The tank-free instantaneous heater is what makes that slimmer profile possible.
The practical difference in overall size between the two seats is minimal — they share nearly identical dimensions.
Where they diverge is in visual profile.
The S2’s side arm control panel adds a visible element to the right side of the seat.
The S5 has no panel at all — it’s a clean, seamless oval that looks more integrated into the toilet.
If bathroom aesthetics matter to you — or if you’re choosing a highly-rated bidet toilet setup for a newly renovated bathroom — the S5’s cleaner look is a genuine advantage.
Winner: S5 — the panel-free design is more modern and easier to clean around.
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Verdict — Which One Should You Buy?
Buy the TOTO WASHLET S2 if…
You live alone or with one other person who doesn’t mind using the same settings.
You prefer the tactile simplicity of physical buttons directly on the seat.
You want the full TOTO WASHLET experience — unlimited warm water, EWATER+, PREMIST, heated seat — at the lower price point in the S-series.
You’re replacing an older C2 or another entry-level WASHLET and want a direct upgrade without paying for features you won’t use.
Buy the TOTO WASHLET S5 if…
You share the bathroom with family members who each have their own spray and temperature preferences.
You want a wall-mounted remote that keeps controls accessible without reaching over to the seat.
You care about a clean, minimal aesthetic in your bathroom.
You want the most future-proof seat at this price tier — the four user presets, five dryer settings, auto energy saver, and sleek remote give you room to grow into the features.
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FAQ
What happened to the TOTO C2 and C5?
Both the TOTO WASHLET C2 and C5 have been discontinued as of 2025.
TOTO replaced them with the new S-series — the S2 replaces the C2, and the S5 replaces the C5.
Both new models carry forward everything the C-series offered, and add the significant upgrade of instantaneous water heating, which means unlimited warm water instead of the tank-limited supply of the older seats.
Do both seats require a professional for installation?
No — both the S2 and S5 are designed for DIY installation.
The package includes all mounting hardware, a brass T-valve, and connection hardware.
Most people complete the installation in 20 to 40 minutes.
You will need a GFCI electrical outlet within reach of the toilet.
If your bathroom doesn’t have one nearby, that’s the one part that requires a licensed electrician.
For more on fitting a WASHLET to your toilet, check our guide on whether you can install a bidet on any toilet.
Is the S5 worth the extra cost over the S2?
If you live alone and have fixed preferences, probably not.
The core cleaning performance is identical — same heater, same spray technology, same EWATER+ and PREMIST.
You’d be paying more purely for the wireless remote and user presets.
But if you share the bathroom with two or more people, or simply prefer the convenience of a wall-mounted remote, the S5 is absolutely worth it.
The four preset slots alone make it a different product for shared households.
Can I use these seats with a round toilet bowl?
Both the S2 and S5 are available in round versions as well as the elongated models.
The elongated S2 is model SW3346#01 and the elongated S5 is SW3446#01.
Round versions are SW3345#01 and SW3445#01 respectively.
If you’re unsure of your toilet’s shape, measure from the mounting bolt holes to the front rim — elongated bowls measure approximately 18.5 inches.
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Conclusion
Both the TOTO WASHLET S2 and S5 are excellent seats — and either one is a significant upgrade over the discontinued C2 and C5 they replaced.
The instantaneous water heater alone makes both of them better than what came before.
The decision really comes down to how your household uses the bathroom.
If simplicity and value are what matter most, the TOTO WASHLET S2 delivers everything you need.
If you want personalization, a cleaner aesthetic, and a wireless remote that makes the whole experience more convenient, the TOTO WASHLET S5 is the one to get.
Whichever you choose, you’ll be getting one of the best heated bidet toilet seats on the market — and a bathroom upgrade you’ll wonder how you lived without.
Looking to explore more options? Check out our bidet toilet seat comparison chart or browse our picks for the best bidets for home use.
If you’re still weighing your options and want a broader view of the TOTO lineup, our guide on the best bidet brands covers how TOTO stacks up against the competition.
