Online Synthesizer

How the Online Synth Bass Works

This free online synth bass gives you a deep, punchy synth bass sound in your browser, with no download, install or sign-up. It plays across 37 keys, so you can write bass lines, test grooves or practice low end parts for electronic music. A progress circle shows while the sounds load, and playing starts once every note is ready.

Play with Keyboard, Mouse or Touch

You can play the synth bass by clicking the keys, tapping them on a touch screen or typing on your computer keyboard. The bottom letter row plays the white keys and the row above plays the black keys, with the top letter row and number row covering the higher notes. The Keys and Notes buttons show or hide the labels, and the Play guide shows the layout.

Low End Control

This is a deep synth bass, and the low notes on the left are the heaviest. Combine it with the Bass and Warmth knobs for extra weight, use the Transpose buttons to find the right key for your track, and add a little compression from the Master knobs to keep the low end tight. The Sustain Pedal is on by default, and holding the space bar acts as a pedal.

Transpose, Volume and Sound Settings

The Sound panel groups its round knobs into Notes, Space, Tone and Master. Notes controls playback speed, transpose, sustain length and touch dynamics, Space adds reverb, room size and echo, Tone shapes bass, mid, treble and warmth, and Master sets stereo width, compression and overall volume. Drag a knob up or down to change it, double-click to reset it, or pick a ready preset such as Concert hall, Warm vintage or Cathedral. The Transpose buttons move the synth bass up or down by semitones to match a singer or another instrument, the volume slider goes up to 200 percent, and your settings are remembered for your next visit.

Record, Play Back and Download

Use the Record button to capture whatever you play on the synth bass. Your take shows on a timeline, so you can listen back, select a part by dragging and clear it when you want a fresh start. The Demo button plays a short tune you can record as well. In the Download panel you can export your recording as MP3 or WAV with your choice of bitrate, sample rate and mono or stereo, save the whole take or just the selected part, normalize the level, let the last notes ring out, trim silence at the start and add fades. Everything is created locally in your browser, with no upload and no sign-up.

Works on Every Screen

This online synth bass works on desktop, tablet and mobile. The top right buttons switch the light or dark theme and full screen mode, and the layout resizes so it stays comfortable on any screen size.