Stereo to mono converter
Stereo to Mono Converter
- 1st conversion free
- No installation
- No plugin
- Files stay local
Drop a stereo audio file
WAV, AIFF, MP3, M4A, FLAC, OGG. Stereo or multichannel, up to 32 tracks. Analysed locally. Drop several files for Pro batch mode.
✓ 1st conversion free. ✓ Your audio stays on your device.
Watch how to convert stereo to monoWhat this tool does for you
- Split a stereo file into discrete left and right mono files
- Or fold both channels down to a single mono track
- No level surprises: the summing is predictable and shown before export
- Export WAV, AIFF or MP3 at the rate and depth your delivery asks for
- Everything runs in your browser. Files are never uploaded to a server.
How it works
01. Drop the stereo file
Specs and a waveform per channel appear instantly.
02. Choose the operation
Sum L+R to one mono file, or split them into two.
03. Download
WAV, AIFF or MP3 at the rate and depth you choose.
Stereo to mono: splitting versus summing
Two very different operations
Splitting a stereo file gives you two mono files, one per channel, with nothing mixed together. Summing gives you one mono file containing both channels added and level-compensated. If someone hands you a stereo recording where the boom is on the left and a lav on the right, you want the split, not the sum, because summing would glue two unrelated mics into one unfixable track.
Phase and the mono fold
When two channels carry the same source with a slight time offset, summing them to mono produces comb filtering: a hollow, phasey tone. This is why a mono fold should always be auditioned before export, and why dialogue captured on two spaced mics is better delivered split.
Professional use cases
Video editing
Fix a clip that plays only on one side by splitting it and re-using the good channel.
Location sound
Separate a boom/lav pair recorded to a stereo track into two editable mics.
Podcasting
Deliver a mono voice track for platforms and telephony playback while keeping the stereo master.
Two operations, two very different results
Convert to mono (sum)
L + R → one mono file
Both channels are averaged into a single mono signal. Use it when left and right carry the same programme — a stereo music bed, a stereo mix, a podcast master heading for a mono playback chain.
Split L/R
L → mono file
R → mono file
The two channels are separated into independent mono files with nothing mixed. Use it when the sides carry different microphones — a boom left, a radio mic right — or when only one side is usable.
Pick the mode in the export panel above. If you are unsure, split first and listen: the split is reversible, the sum is not.
Convert stereo to mono
Summing to mono is the right move when a stereo file is really one programme and the destination is mono: telephony, a single speaker, a mono broadcast leg, or a voice track that will be panned in the mix anyway. Averaging the channels keeps the level where it was instead of adding 6 dB and clipping the peaks.
The one thing to listen for is phase. When both channels carry the same source captured by two spaced microphones, summing them produces comb filtering — a hollow, slightly phasey tone. Play the file back before you export; if it sounds thin, the material wants the split, not the sum.
Split stereo into separate left and right mono files
A very common production case is not a stereo recording at all: it is two unrelated microphones written into one stereo file because the recorder had two inputs. Summing those would be a mistake. Splitting gives the editor two mono tracks that can be levelled, muted and processed independently.
The same operation applies when only one side is usable: untick the bad channel and export the good one on its own. Splitting a stereo file into mono tracks walks through the decision in more detail. If the file has more than two channels, the PolyWAV splitter handles the same job up to 32 channels.
When to sum, when to split
| Situation | Do this |
|---|---|
| Boom on the left, lav on the right | Split into two mono files |
| Sound only on one side | Split, keep the usable channel |
| Stereo music bed for a mono broadcast leg | Sum to one mono file |
| Podcast voice recorded as identical dual mono | Sum to one mono file |
| Stereo ambience or a stereo mix | Leave it stereo |
| A 4, 8 or 16-channel take | Use the PolyWAV splitter instead |
How to convert stereo to mono
- Drop a WAV, AIFF, MP3, M4A, FLAC or OGG file on the tool at the top of the page.
- Look at the two waveforms and play the file back to hear what each side contains.
- Untick a channel if you only want one side.
- Choose the export mode: Sum to one mono file, or Split into mono files.
- Set the format, sample rate and bit depth, or leave them on Source.
- Export and download.
See how it works
How to Convert Stereo to Mono — No DAW RequiredWatch the step-by-step tutorial and choose between summing to mono and splitting left and right.Watch the tutorial →Your audio stays on your device
Decoding, processing and export all run in your browser: compressed formats are decoded with the Web Audio API, and WAV, AIFF and MP3 files are written by JavaScript in the page. Your audio is never uploaded to our servers. Only anonymous page analytics and, if you sign in, your account and payment details go online.
Frequently asked questions
- How do I convert a stereo file to mono?
- Drop the file above, keep both channels ticked, choose the Sum to one mono file export mode, then export. Left and right are averaged into a single mono file at the sample rate and bit depth you pick.
- How do I split a stereo file into two mono files?
- Same start, but choose the Split into mono files export mode. You get one mono file for the left channel and one for the right, with nothing mixed together.
- What is the difference between summing and splitting?
- Summing mixes left and right into one mono signal. Splitting separates them into two independent mono files. If the two channels carry different microphones, you want the split; summing would glue two unrelated mics into one track you cannot undo.
- How do I extract only the left or only the right channel?
- Untick the channel you do not want and export in Split mode. The remaining channel is written as a single mono file at the original sample rate and bit depth.
- Why does my interview only have sound on one side?
- The microphone was recorded to one input of a stereo pair. Keep that channel and export it as mono, and the voice sits in the centre for every listener.
- Will summing to mono make the file louder or clip it?
- No. The selected channels are averaged rather than added, so the peak level of correlated material stays where it was and the fold-down cannot clip.
- Does converting stereo to mono lose quality?
- Splitting does not: the samples of each channel are copied into their own file when you export WAV at the source rate and depth. Summing is a real mix, so it is not reversible, and two spaced microphones summed together can comb-filter. Audition the result before you commit.
- Is mono the right choice for dialogue?
- For a single voice, yes. A mono dialogue track behaves predictably on every playback system and avoids phase problems when it is later panned or folded down.
- Which formats can I load and export?
- Load WAV, AIFF, MP3, M4A, FLAC or OGG. Export WAV, AIFF or MP3, at 44.1 to 192 kHz and 16, 24 or 32-bit, or leave the settings on Source to keep what the file already has.
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