Free Online Autopanner
Rhythmic left-right stereo motion.
Drag & drop your audio file here
or
Max file size: 100 MB · MP3, WAV, FLAC, OGG
Original
beats per minute
musical key
How many left-right cycles per second. Slow rates feel dreamy; fast rates feel like tremolo.
How far the sound swings. 100% sweeps fully left to fully right.
Processing…
Result
How it works
An autopanner is one of the oldest modulation effects in music: a low-frequency oscillator continuously sweeps the stereo position of the sound from left to right. Set a slow rate for gentle, floating movement, or push toward 10 Hz for the rapid chop of classic tremolo-pan.
Depth controls how far the image swings - at 100% the sound travels fully from one speaker to the other; at lower values it wobbles subtly around the center. The effect is built from a StereoPannerNode driven by an OscillatorNode, the same architecture as hardware panning pedals.
It runs as a real-time Web Audio effect, so you hear changes instantly. All processing is client-side in your browser: your files never leave your device and nothing is uploaded.
Frequently asked questions
What is auto-panning used for?
Auto-panning moves sound rhythmically between the left and right speakers. Slow rates create dreamy, floating movement on pads and vocals; fast rates create the choppy tremolo-pan heard in psychedelic rock and electronic music.
How is this different from 8D audio?
Both use an LFO on a stereo panner, but the autopanner supports much faster rates (up to 10 Hz) and adjustable depth, making it a precision creative tool rather than just the slow 8D orbit effect.
Will it work on mono files?
Yes - a mono source pans cleanly across the stereo field. Stereo files keep their internal stereo image while the whole image swings left and right.
Is there a file size limit? Is it private?
Files up to 100MB are supported. The LFO panning runs in real time in your browser - your audio never leaves your device.