Mono to Stereo Converter
Turn mono recordings into stereo files — as a plain two-channel copy for platforms and editors that require stereo, or with a wide pseudo-stereo, Haas or panning effect for a fuller sound. Fast, free and private.
- No upload
- 4 stereo methods
- Mono-compatible
- Free
Drop audio files here
or
You can also paste with Ctrl+V (⌘+V on Mac) or drop a whole folder.
MP3 · WAV · M4A · AAC · FLAC · OGG · OPUS · MP4 / MOV video
Your files are processed on your device and are never uploaded.
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Done — your files are ready
You changed the settings — click the button again to update the result.
How to convert mono to stereo
Three quick steps.
- 1
Add mono files
Drop your mono recordings onto the page.
- 2
Choose a method
Dual mono for compatibility, pseudo stereo or Haas for width, or pan the sound.
- 3
Convert & download
Listen with headphones, compare with the original and download.
Stereo from mono — your way
Four methods, all adjustable.
Dual mono
An exact copy on both channels — required by many video editors, DAWs and upload forms.
Pseudo stereo
A wider sound that still collapses cleanly back to mono — safe for radio and phone speakers.
Haas effect
A short delay on one side creates a spacious, wide image.
Panning
Place a voice or instrument anywhere in the stereo field.
A/B compare
Switch between original and result while listening.
Batch
Convert many files at once and download a ZIP.
Private
Your audio stays on your device.
Free
No sign-up, no watermark.
Can you really make mono audio stereo?
A mono recording has only one channel, so there is no real left/right information to recover. What you can do is create a two-channel file — either with identical channels (dual mono, which sounds exactly like the original) or with an effect that creates a sense of width.
Pseudo stereo uses two complementary comb filters: some frequencies lean left, others right. Summed back to mono they cancel out perfectly, so it is safe for any playback system. The Haas effect delays one channel by 5–30 ms, which the ear perceives as width rather than echo — very effective on headphones, but it can sound slightly hollow on mono speakers.
Use Pan to place a mono source, for example a guest’s voice slightly to one side in an interview.
Which method?
| Goal | Method |
|---|---|
| Platform or editor requires stereo | Dual mono |
| Fuller sound, still mono-safe | Pseudo stereo |
| Very wide sound on headphones | Haas effect (10–20 ms) |
| Position a voice or instrument | Pan |
Tips
- Going the other way? Use Stereo to Mono.
- Check whether a file is mono or stereo with the Audio Metadata Viewer.
- Balance the volume afterwards with the Volume Normalizer.
- Convert to another format at the same time — just pick it under Output format.
Frequently asked questions
Can’t find your answer? Contact us — we reply quickly.
How do I convert mono to stereo?
Drop the mono file onto this page, choose “Dual mono” (or an effect) and click “Convert to stereo”.
Will dual mono sound different?
No. Both channels contain the same signal, so it sounds exactly like the original — it is simply stored as stereo.
What is the best fake stereo effect?
Pseudo stereo is the safest because it stays mono-compatible. The Haas effect sounds wider on headphones but can colour the sound on mono speakers.
What happens with stereo input files?
They are mixed to mono first, then converted with the chosen method.
Are my files uploaded?
No. Everything runs in your browser.
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