At $900, both come with a stand, three pedals, and 88 weighted keys. Both are 88-note consoles from brands you can trust. On paper, the KDP-120 and YDP-S35 look nearly identical — which is exactly why buyers search for comparisons. There must be a real difference, they sense. There is.
You are actually choosing between two different philosophies about what a beginner piano needs to do. One prioritizes how the piano feels three years from now. The other prioritizes how you'll learn with it starting on day one. Neither position is wrong.
The Depth Myth, Corrected First
Almost every comparison article online says the YDP-S35 is the slimmer piano. This is wrong. The Kawai KDP-120 is 260mm deep. The Yamaha YDP-S35 is 309mm deep. Kawai is the slimmer console in this pair by nearly 50mm. If wall space is your primary constraint, the KDP-120 wins without argument — despite its reputation as the "fuller-featured" option.
Both are legitimately slim consoles that hug a wall nicely. But if you've been told the Yamaha is the space-saver here, that information is incorrect.
The Key Action: Where the Long-Term Difference Lives
The KDP-120 uses Kawai's Responsive Hammer Compact action. The YDP-S35 uses Yamaha's Graded Hammer Standard. Both are entry-level weighted actions with realistic graduation from heavier bass keys to lighter treble keys. Neither is dramatically superior. But they feel different, and those differences compound over time.
GHS — Yamaha's action — is typically described as crisp and responsive with a slightly lighter overall weight. Players who come from acoustic piano experience sometimes find it lighter than expected, but it's quick and reliable. Kawai's RHC is generally described as having a slightly heavier, more resistant feel at the bottom of the key travel. Some find it more satisfying as a training tool precisely because it offers more physical feedback.
For a beginner, the action difference matters more than it would for an advanced player — because the action you learn on shapes your muscle memory. If your next piano has a noticeably different resistance profile, that adjustment takes real time. This isn't a reason to avoid either piano, but it's a reason to try them both in a store if you have the chance.
Speakers: 30W vs 16W in a Living Room
The KDP-120 has 30W of amplification. The YDP-S35 has 16W. That's nearly double the power in the Kawai.
In a small, quiet room, both will serve you adequately for personal practice. But in a moderate-sized living room with ambient noise — a family home, a flat with street sound coming through the windows — the difference is audible. The KDP-120 fills the room more convincingly. The YDP-S35's 16W is adequate for personal practice but can feel thin if you want the piano to sound like a piano rather than a practice tool. This is one of the more concrete real-world differences between these two instruments.
App Connectivity: A Meaningful Edge for Young Learners
The Yamaha YDP-S35 supports Yamaha's Smart Pianist app via USB cable. This is a real and practical feature for families with children using structured learning apps. Smart Pianist integrates with the piano's built-in lesson library (303 preset songs) and provides interactive features that make practice sessions easier for kids to follow independently.
The KDP-120 has no official app ecosystem at this price tier. It has USB MIDI, which means you can technically connect it to apps like Simply Piano or Flowkey via cable — but there's no dedicated app, no official integration, and no built-in guidance. For a self-teaching adult who already uses a tablet-based app with their own subscription, either piano works through a cable. For a parent setting up structured lessons for a child, the YDP-S35's Smart Pianist support is a practical convenience the Kawai genuinely lacks.
The YDP-S35 also has 303 built-in preset songs versus the KDP-120's 182. If your child's teacher assigns pieces from the built-in library as homework, more songs available means fewer gaps.
Silent Practice: A Quick Note
Both pianos have dual headphone jacks — a 6.3mm and a 3.5mm — so a parent can monitor while a child practices. Neither has Bluetooth; a USB cable is required for any app connectivity. These are ties.
The Honest Recommendation
If the room is tight on space, buy the KDP-120 — it is actually the slimmer console, contrary to popular belief.
If you have children starting structured lessons and want seamless integration with learning apps, the YDP-S35's Smart Pianist connectivity is a genuine advantage. The larger preset song library supports that same use case.
If the primary driver is the feel of the piano and the quality of sound in a living room, the KDP-120 delivers better speakers and a key action that experienced players generally prefer as a training foundation. These are not minor differences at this price point — they represent genuinely different product philosophies at identical prices.
For a first-time adult buyer who wants a complete, reliable piano and doesn't have children doing app-based lessons, the KDP-120 is the stronger all-around pick. For a family with a young child and a specific learning app ecosystem in mind, the Yamaha earns its consideration.