Main trade-off
Kawai ES120
The internal three-song recorder stores performance data. USB carries MIDI, so capturing its own piano sound on a computer needs an audio path such as the line outputs and an interface.
Head-to-head
Kawai ES120 vs Casio PX-S3100: Casio records standalone WAVs, neither supplies a computer USB audio interface
The short answer
Choose ES120 for a home piano with built-in Bluetooth and a focused 25-sound selection, especially if you already have a way to capture its analog line output. Choose PX-S3100 for stand-alone WAV recording, a shallower body and optional battery operation. Neither USB-B connection is a built-in USB audio interface. On Casio, plan a wired backing source if the flash drive replaces the supplied Bluetooth adapter.
Before you choose
The reasoning and the trade-offs
Recording for a teacher is different from replaying a practice take
A child can replay a take from either piano, but sending the piano’s own sound to a teacher is a different task. Kawai’s internal recorder stores performance data and its computer port carries MIDI. You need an audio capture route, such as its line outputs into a compatible interface. Casio can write a WAV recording to a supported USB flash drive without a computer. That makes Casio the more direct choice for this handoff, while Kawai is straightforward if the household already owns the recording equipment.
What this is based on
Documented recording formats crossed with a transferable-audio requirement. No assumption that MIDI contains the internal piano sound.
Main trade-off
Casio PX-S3100
The WU-BT10 Bluetooth adapter and a USB flash drive use the same USB-A port. You cannot occupy it with both accessories at once.
Kawai ES120
- Choose it for
- You want Bluetooth audio built in, with no plug-in adapter to keep track of, and 25 sounds cover your practice.
- You use a compatible audio interface or recorder for sound capture, and value dedicated line outputs plus mixed-size headphone sockets.
- Main trade-off
- The internal three-song recorder stores performance data. USB carries MIDI, so capturing its own piano sound on a computer needs an audio path such as the line outputs and an interface.
Casio PX-S3100
- Choose it for
- You want a WAV recording without connecting a computer. Its USB flash drive replaces the WU-BT10 adapter, so plan backing-track connections.
- A 232 mm bare-body depth or six-AA battery option fits a room you cannot dedicate to music. Allow support and cable clearance.
- Main trade-off
- The WU-BT10 Bluetooth adapter and a USB flash drive use the same USB-A port. You cannot occupy it with both accessories at once.
About this comparison
Compare Kawai ES120 and Casio PX-S3100 for shared practice, phone backing tracks and sending a recording. See which connections and power limits matter at home.
These are portable 88-key hammer-action pianos with speakers and two headphone outputs. A home learner can realistically choose between Kawai’s focused piano setup and Casio’s wider arranging and stand-alone recording options.
Winner by situation
Start with what you need it to do
I want a WAV file without a computer or audio interface
Casio records audio to a supported flash drive. Kawai needs a separate audio-capture route.
- Kawai ES120
- Caution
- Casio PX-S3100
- Better fit
I want built-in Bluetooth without a removable dongle
Kawai integrates Bluetooth. Casio uses the supplied WU-BT10 adapter.
- Kawai ES120
- Better fit
- Casio PX-S3100
- Good
The practice spot has no convenient outlet
Casio has a qualified battery option. Kawai needs AC power.
- Kawai ES120
- Caution
- Casio PX-S3100
- Better fit
Two people need headphones together
Both have two sockets. Match the plugs and do not assume independent volume.
- Kawai ES120
- Similar
- Casio PX-S3100
- Similar
I want piano sound recorded through one USB cable
Their computer USB connections carry MIDI rather than an integrated audio-interface signal.
- Kawai ES120
- Not suitable
- Casio PX-S3100
- Not suitable
I mainly want a focused piano with fewer sounds to browse
Kawai offers 25 sounds. Casio adds a much broader arranging set, useful when that is the goal.
- Kawai ES120
- Better fit
- Casio PX-S3100
- Good
What matters in practice
The differences that matter
Recording for a teacher is different from replaying a practice take
A child can replay a take from either piano, but sending the piano’s own sound to a teacher is a different task. Kawai’s internal recorder stores performance data and its computer port carries MIDI. You need an audio capture route, such as its line outputs into a compatible interface. Casio can write a WAV recording to a supported USB flash drive without a computer. That makes Casio the more direct choice for this handoff, while Kawai is straightforward if the household already owns the recording equipment.
How we reached this conclusion
Documented recording formats crossed with a transferable-audio requirement. No assumption that MIDI contains the internal piano sound.
Casio’s wireless backing track and flash recorder need a connection plan
You may want to play along with a phone and record at the same time. Casio’s supplied WU-BT10 occupies the USB-A port that a recording flash drive needs. Remove the adapter for the drive and that Bluetooth route is gone. Its wired Audio In provides another backing-source route with the correct cable. Kawai’s Bluetooth is internal, so no dongle occupies a port, but it still needs an external audio-capture setup to record its sound. Confirm what your chosen recorder captures before promising a combined piano-and-backing file.
How we reached this conclusion
One physical USB-A port and mutually exclusive accessories, crossed with simultaneous playback and recording. The content of an external recording mix is not assumed.
A piano that moves between rooms needs more than a slim body
Casio’s body is 48 mm shallower and can run on six AA alkaline batteries. That can help when practice moves off the dining table into another room with fewer outlets. The quoted roughly two hours is a continuous-demo test, so do not treat it as a promised lesson schedule. Kawai needs its AC adapter, but keeps Bluetooth inside the instrument instead of in a small removable dongle. Both still need a stable, correctly sized support and space for plugs and the music rest. Neither bare depth proves the whole setup fits.
How we reached this conclusion
280 minus 232 equals 48 mm, about 1.9 inches. Power and accessory handling crossed with a shared-room setup. No battery duration or support-load guarantee.
Choice A
Kawai, ES120
ES120
You want Bluetooth audio built in, with no plug-in adapter to keep track of, and 25 sounds cover your practice.
- Best matched use
- You want Bluetooth audio built in, with no plug-in adapter to keep track of, and 25 sounds cover your practice.
Checked facts
- 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
Choice B
Casio, PX-S3100
PX-S3100
You want a WAV recording without connecting a computer. Its USB flash drive replaces the WU-BT10 adapter, so plan backing-track connections.
- Best matched use
- You want a WAV recording without connecting a computer. Its USB flash drive replaces the WU-BT10 adapter, so plan backing-track connections.
Checked facts
- 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
Meaningful differences
What changes the fit
| What changes | Kawai ES120 | Casio PX-S3100 | Why it matters |
|---|---|---|---|
| Phone backing audio | Bluetooth audio built into the piano | Bluetooth through supplied WU-BT10 USB-A adapter, or wired Audio In | Casio’s wireless accessory occupies the port used for a flash recording drive. |
| Stand-alone performance capture | Three-song internal recorder stores performance data | MIDI recorder plus WAV audio recording to USB flash | A replayable performance inside a piano is different from an audio file you can send. |
| Computer USB connection | USB MIDI | USB MIDI | MIDI sends musical instructions, not the internal piano sound. Neither is a USB audio interface here. |
| Bare depth | 280 mm | 232 mm | Casio is 48 mm shallower before the music rest and working clearance. This does not certify a desk or stand fit. |
| Power | AC adapter | AC adapter or six AA alkaline batteries | Casio can move away from an outlet, but the supported runtime condition remains important. |
| Headphone sockets | One 6.3 mm and one 3.5 mm | Two 3.5 mm | Two people can connect directly to either with appropriate plugs. This does not provide independent volume. |
| Sound selection | 25 sounds and 100 drum rhythms | 700 tones and 200 rhythms with accompaniment functions | Kawai keeps a focused sound set. Casio offers more arranging options to explore beyond piano practice. |
What you give up
Every choice has a cost
If you choose Kawai ES120
- The supplied F-1SP is a switch pedal. Budget for a documented compatible half-damper option if the learner’s lessons require it.
If you choose Casio PX-S3100
- The roughly two-hour battery figure uses continuous demo playback with alkaline cells. It is not a guarantee for a full afternoon of lessons or external equipment.
Recommendation switch
The decision flips if...
Sending stand-alone audio files or battery-powered room changes is important
Choose Casio PX-S3100. Casio documents both routes, with a shared USB port and conditional runtime to plan around.
A focused home piano with built-in Bluetooth is enough and audio capture is already covered
Choose Kawai ES120. Kawai avoids the removable wireless adapter and provides dedicated analog outputs.
The requirement is an integrated USB audio interface
Choose neither. Both computer ports carry MIDI in the documented configurations.
What matters in practice
Before you choose
You want easy phone-backed practice and a recording you can send to family. ES120 keeps Bluetooth built in, but its internal recorder stores performance data. Casio records WAV files, while its Bluetooth adapter and flash drive compete for one USB-A port.
What this comparison cannot tell you
- No key-action, mechanical-noise, latency or touch-quality winner is inferred from manufacturer specifications.
- Battery and physical dimensions are used only in their stated configurations.
What the facts say
What the comparison shows
Useful conclusions from the current digital pianos comparison, followed by the checked facts used to reach them.
See the checked facts and calculation notes
| Product | Needs matched | Checked facts | Source records |
|---|---|---|---|
| Kawai ES120 |
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| Casio PX-S3100 |
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Ready to choose?
Check the price. Read the owner reviews.
Open either model on Amazon to check the current price, customer reviews and delivery options.
Kawai ES120
You want Bluetooth audio built in, with no plug-in adapter to keep track of, and 25 sounds cover your practice.
You use a compatible audio interface or recorder for sound capture, and value dedicated line outputs plus mixed-size headphone sockets.
See price & reviews on AmazonCasio PX-S3100
You want a WAV recording without connecting a computer. Its USB flash drive replaces the WU-BT10 adapter, so plan backing-track connections.
A 232 mm bare-body depth or six-AA battery option fits a room you cannot dedicate to music. Allow support and cable clearance.
See price & reviews on AmazonLinks open in a new tab.