Free Online Synthesizer — Play and Keep an Idea

Play and record without an account. Save sound settings in this browser; download recordings before leaving or refreshing the page.

Loading keyboard…Press Z, X, C — or tap a key

Middle range Note names

Press the letters shown on the keys, or click to play.or hold Space

Try it:

Brightness

6800 Hz

Volume

50%

Reverb 40%

maintained by Online Keyboard Synth

What Is Included for Free?

The current tool has no site account, trial screen, or locked presets.

Play: Nine factory presets. Click or tap the piano, or use the displayed computer keys. MIDI input needs a supporting browser and device.
Shape the sound: Oscillators, a resonant filter, an amplitude envelope, reverb, and delay. Open Sound design for the deeper controls.
Save settings: Use My sounds to name and keep a sound in this browser. This saves its settings, not a recording.
Record audio: Record the browser synth, listen to a take, and download it in the browser's format or convert it to WAV.

What Stays When You Leave?

Sound settings and recordings have different lifetimes
Item	Kept where?	After refresh?
Last sound	Auto-saved settings in this browser.	Restored if browser storage is available.
My sounds	Up to 30 named sounds in this browser.	Available here until removed or site data is cleared.
Recorded takes	Audio held in this page's memory.	Lost. Download each take first to keep a file.

Example: 29 saved sounds + 1 new sound fills the 30-sound library. Remove one named sound to make room for another.

Saved settings do not sync to another browser or device. Browser storage can be blocked or cleared; private-browsing data can disappear when that session ends. It is not a backup. See MDN's browser storage explanation.

Keep an Idea in Three Steps

Choose a preset and play a note. If silent, use Enable sound and check Volume and your audio output.
Choose Record, play, then stop. A take appears with a playback control. Use it to review what you played.
Download before leaving. Use the take's Download link for its original format, or Get .wav and then Download .wav.

These files are audio. They are not editable .mid notes or a multitrack project. The recorder captures this synth's output, not your microphone or a hardware keyboard's own audio.

The original extension depends on your browser, such as .webm or .m4a. If WAV conversion fails, download the original take. Recording support and available resources vary; MDN explains the format check.

If Saving or Recording Fails

The sound library is full: At 30 sounds, remove a named sound you no longer need before saving another. Removing it does not remove an already downloaded audio file.
Browser storage is unavailable: The synth can still play. Allow this site's browser storage if you want settings to persist; recording downloads are separate from saved settings.
Record or Get .wav fails: Read the message beside the control. If a take exists, keep its original download. If no take was captured, try again in a browser that supports recording.
I want to remove saved settings: Remove in My sounds deletes one named sound. Clear this site's data in browser settings to remove all named sounds and the restored last sound. This does not delete downloaded files.

Audio is processed locally by the synth. The page still requests fonts and analytics resources. Read the storage and third-party details in Privacy for the wider data flow.

Choose Your Next Step

Download any take you want to keep before following a link to another page.

Learn waveforms, filters, envelopes, and effects with the homepage's guided controls.
Follow the computer-keyboard map and practice examples to explore notes.
Connect a MIDI keyboard and check its status if you want an external input.

Current features and saving rules checked: 2026-10-06.

Frequently asked questions

Is the synthesizer free to use?

Yes. The current tool has no account requirement, trial screen, or locked presets. Playing, sound controls, My sounds, and recording are available without a site payment. This describes the current version, not a promise about future services.

Do I need to install anything?

No installer or plugin is needed for screen keys or computer-keyboard playing. The page needs JavaScript and browser audio support. An external MIDI device may have its own setup requirements.

Can I use it on a phone?

Tap the on-screen keys and use Lower or Higher to change the range. Audio and recording depend on your mobile browser and settings. Computer-keyboard shortcuts need a physical keyboard; MIDI support varies by browser.

Can I download MIDI notes or a project file?

No. The downloads contain audio, not editable MIDI notes or a multitrack project. My sounds keeps sound settings in this browser; it does not export a preset file or sync a library to another device.