The catch
Kawai ES120
Its internal three-song recorder holds performance data. Since USB carries MIDI, getting the piano’s own sound onto a computer takes an audio path, for example the line outputs plus an interface.
Side by side
Kawai ES120 vs Casio PX-S3100 for Practice, Recording and Space: Neither supplies a computer USB audio interface, and Casio records standalone WAVs
Quick verdict
ES120 is the choice for a home piano with built-in Bluetooth and a focused 25-sound selection, particularly if you already have a way to capture its analog line output. PX-S3100 is the choice for stand-alone WAV recording, a shallower body and optional battery operation. Neither piano’s USB-B connection is a built-in USB audio interface. If the flash drive replaces the supplied Bluetooth adapter on the Casio, plan a wired backing source.
Before you buy
Why, and what it costs you
Recording for a teacher and replaying a practice take are not the same
Either piano lets a child replay a take, but getting the piano’s own sound to a teacher is another matter. Kawai’s internal recorder stores performance data, and its computer port carries MIDI, so you’d need an audio capture route, for example its line outputs into a compatible interface. Casio can write a WAV recording to a supported USB flash drive with no computer. For this handoff Casio is the more direct choice, and Kawai is a simple option if the household already owns the recording equipment.
Where this comes from
This sets the documented recording formats against a need for audio that can be passed along. MIDI is not assumed to contain the internal piano sound.
The catch
Casio PX-S3100
One USB-A port serves both the WU-BT10 Bluetooth adapter and a USB flash drive, and it can’t hold both accessories at the same time.
Kawai ES120
- Why pick it
- Built-in Bluetooth audio, with no plug-in adapter to keep track of, is what you want, and 25 sounds cover your practice.
- A compatible audio interface or recorder handles your sound capture, and you value dedicated line outputs along with headphone sockets in mixed sizes.
- The catch
- Its internal three-song recorder holds performance data. Since USB carries MIDI, getting the piano’s own sound onto a computer takes an audio path, for example the line outputs plus an interface.
Casio PX-S3100
- Why pick it
- You want a WAV recording with no computer connected. The USB flash drive takes the place of the WU-BT10 adapter, so plan how backing tracks will connect.
- Your room cannot be given over to music, and a 232 mm bare-body depth or six-AA battery option suits it. Leave clearance for support and cables.
- The catch
- One USB-A port serves both the WU-BT10 Bluetooth adapter and a USB flash drive, and it can’t hold both accessories at the same time.
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What this page compares
Kawai ES120 or Casio PX-S3100 for shared practice, phone backing tracks and sending off a recording? See which connections and power limits count at home.
Both are portable 88-key hammer-action pianos with speakers and two headphone outputs. For a home learner, the realistic choice is Kawai’s focused piano setup or Casio’s broader options for arranging and stand-alone recording.
Which one fits
Pick the situations that sound like you
I want to make a WAV file with no computer or audio interface
Casio saves audio to a supported flash drive, whereas Kawai calls for a separate audio-capture route.
- Kawai ES120
- Caution
- Casio PX-S3100
- Better fit
I want Bluetooth built in rather than a removable dongle
Bluetooth is built into Kawai. Casio relies on the supplied WU-BT10 adapter.
- Kawai ES120
- Better fit
- Casio PX-S3100
- Good
No convenient outlet is near the practice spot
Casio can run on batteries, within limits. Kawai requires AC power.
- Kawai ES120
- Caution
- Casio PX-S3100
- Better fit
Two people have to use headphones together
Each has two sockets. Make sure the plugs match, and don’t count on independent volume.
- Kawai ES120
- Similar
- Casio PX-S3100
- Similar
I want the piano sound recorded over a single USB cable
Over their USB connections to a computer, both send MIDI. Neither sends the signal of an integrated audio interface.
- Kawai ES120
- Not suitable
- Casio PX-S3100
- Not suitable
Mostly I want a focused piano, with fewer sounds to page through
Kawai has 25 sounds. Casio brings a far broader arranging set, which helps if arranging is what you’re after.
- Kawai ES120
- Better fit
- Casio PX-S3100
- Good
In practice
Differences you will notice
Recording for a teacher and replaying a practice take are not the same
Either piano lets a child replay a take, but getting the piano’s own sound to a teacher is another matter. Kawai’s internal recorder stores performance data, and its computer port carries MIDI, so you’d need an audio capture route, for example its line outputs into a compatible interface. Casio can write a WAV recording to a supported USB flash drive with no computer. For this handoff Casio is the more direct choice, and Kawai is a simple option if the household already owns the recording equipment.
How we worked this out
This sets the documented recording formats against a need for audio that can be passed along. MIDI is not assumed to contain the internal piano sound.
Casio’s wireless backing track and flash recorder call for planning the connections
Playing along with a phone while recording could be exactly what you want. The WU-BT10 supplied with the Casio takes the USB-A port that a recording flash drive needs, so pulling the adapter for the drive also ends the Bluetooth route. The wired Audio In, with the right cable, gives you a different way to bring in the backing source. Kawai’s Bluetooth is internal, so no dongle ties up a port, but recording its sound still requires an external audio-capture setup. Before you promise anyone a combined piano-and-backing file, confirm what your chosen recorder captures.
How we worked this out
Here a single physical USB-A port and accessories that exclude each other meet playback and recording happening together. What an external recording mix contains is not assumed.
A piano that changes rooms needs more going for it than a slim body
The Casio is 48 mm shallower and can run on six AA alkaline batteries, which is useful when practice leaves the dining table for a room with fewer outlets. Its quoted figure of roughly two hours comes from a continuous-demo test, so it shouldn’t be read as a promised lesson schedule. The Kawai requires its AC adapter, though its Bluetooth is inside the instrument and not in a small removable dongle. Either one still needs a stable support of the right size, with room for plugs and the music rest. Neither bare depth proves that the whole setup fits.
How we worked this out
280 minus 232 equals 48 mm, about 1.9 inches. The factors are power and accessory handling in a shared-room setup. Battery duration and support load are not guaranteed.
Option A
Kawai, ES120
ES120
Built-in Bluetooth audio, with no plug-in adapter to keep track of, is what you want, and 25 sounds cover your practice.
- Best for
- Built-in Bluetooth audio, with no plug-in adapter to keep track of, is what you want, and 25 sounds cover your practice.
Facts we checked
- Phone backing audio: Bluetooth audio built into the piano
- Stand-alone performance capture: Three-song internal recorder stores performance data
- Computer USB connection: USB MIDI
- Bare depth: 280 mm
Option B
Casio, PX-S3100
PX-S3100
You want a WAV recording with no computer connected. The USB flash drive takes the place of the WU-BT10 adapter, so plan how backing tracks will connect.
- Best for
- You want a WAV recording with no computer connected. The USB flash drive takes the place of the WU-BT10 adapter, so plan how backing tracks will connect.
Facts we checked
- Phone backing audio: Bluetooth through supplied WU-BT10 USB-A adapter, or wired Audio In
- Stand-alone performance capture: MIDI recorder plus WAV audio recording to USB flash
- Computer USB connection: USB MIDI
- Bare depth: 232 mm
Spec by spec
Where they really differ
| Spec | Kawai ES120 | Casio PX-S3100 | In practice |
|---|---|---|---|
| Phone backing audio | Bluetooth audio built into the piano | Bluetooth through supplied WU-BT10 USB-A adapter, or wired Audio In | The port a flash recording drive needs is taken up by Casio’s wireless accessory. |
| Stand-alone performance capture | Three-song internal recorder stores performance data | MIDI recorder plus WAV audio recording to USB flash | A performance you can replay inside the piano is not an audio file you can send. |
| Computer USB connection | USB MIDI | USB MIDI | MIDI carries musical instructions. It does not carry the internal piano sound. Neither works as a USB audio interface here. |
| Bare depth | 280 mm | 232 mm | Without the music rest and working clearance, Casio is 48 mm shallower. That alone doesn’t confirm it will fit a desk or stand. |
| Power | AC adapter | AC adapter or six AA alkaline batteries | Casio can be used away from an outlet, but the stated runtime condition still matters. |
| Headphone sockets | One 6.3 mm and one 3.5 mm | Two 3.5 mm | With the right plugs, two people can connect directly to either piano. Independent volume doesn’t come with that. |
| Sound selection | 25 sounds and 100 drum rhythms | 700 tones and 200 rhythms with accompaniment functions | Kawai sticks to a focused set of sounds. Casio has more arranging options to explore beyond piano practice. |
Trade-offs
What each pick costs you
With Kawai ES120
- The pedal that comes with it, the F-1SP, is a switch pedal. If the learner’s lessons call for it, budget for a documented compatible half-damper option.
With Casio PX-S3100
- Roughly two hours of battery life is the figure for continuous demo playback on alkaline cells. It doesn’t promise a full afternoon of lessons or use with external equipment.
Change of plan
When the answer changes
Sending stand-alone audio files, or moving between rooms on battery power, matters to you
Go with Casio PX-S3100. Both routes are documented for Casio, and you plan around the shared USB port and the conditional runtime.
A focused home piano with built-in Bluetooth will do, and you already have audio capture handled
Go with Kawai ES120. Kawai has no removable wireless adapter and comes with dedicated analog outputs.
You require a built-in USB audio interface
Neither model fits. In the documented configurations, MIDI is what both computer ports carry.
Decision guide
Before you buy
Easy phone-backed practice and a recording you can send to family are the goals. Bluetooth is built into the ES120, though its internal recorder stores performance data. Casio records WAV files, but its Bluetooth adapter and flash drive compete for one USB-A port.
What this page can’t tell you
- Manufacturer specifications do not let us name a winner for key action, mechanical noise, latency or touch quality.
- Battery figures and physical dimensions apply only to the configurations stated.
By the numbers
What the data shows
What we found across the digital pianos we compare, plus the checked facts behind each finding.
Show the facts and the math
| Product | Needs it meets | Facts we checked | Sources |
|---|---|---|---|
| Kawai ES120 |
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| |
| Casio PX-S3100 |
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Ready to buy
See today’s price and what owners say
Open either model on Amazon for the current price, customer reviews and delivery options.
Kawai ES120
Built-in Bluetooth audio, with no plug-in adapter to keep track of, is what you want, and 25 sounds cover your practice.
A compatible audio interface or recorder handles your sound capture, and you value dedicated line outputs along with headphone sockets in mixed sizes.
See price & reviews on AmazonCasio PX-S3100
You want a WAV recording with no computer connected. The USB flash drive takes the place of the WU-BT10 adapter, so plan how backing tracks will connect.
Your room cannot be given over to music, and a 232 mm bare-body depth or six-AA battery option suits it. Leave clearance for support and cables.
See price & reviews on AmazonEach link opens in a new tab.
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