Stereo to Mono Converter Online
Audio to Mono is a free browser tool and stereo to mono converter online — drop a stereo WAV, MP3, FLAC, AAC, or OGG file and get back a true mono WAV. Nothing is uploaded. Decoding and encoding both happen inside your browser tab using the Web Audio API, so the file never leaves your device. No account, no install, no DAW required.
Drop a stereo audio file above and get a mono WAV back instantly. Everything runs in your browser — no upload, no size limit beyond the 100 MB cap.
Ready to convert? It takes one tap.
Use the free Audio to Mono →How to convert stereo to mono online
Audio to Mono decodes your file with the browser's native audio engine, mixes the channels down, and writes a standard 16-bit PCM WAV — all without a server in between.
- Open capsuletools.app/audio-to-mono/
- Drop your stereo file onto the zone, or tap to browse
- The browser decodes it, mixes it to mono, and offers
[filename]-mono.wavfor download
Conversion is nearly instant for typical file sizes — there's no "Loading decoder…" wait, since the Web Audio API is built into every modern browser.
Choosing a summing method — Average, Left channel, or Right channel
Tap Conversion settings below the drop zone to choose how the two channels combine:
- Average (L+R) — the default. Adds the left and right samples and halves the result, the standard way to downmix stereo to mono without favoring either side.
- Left channel only — keeps just the left channel, discarding the right.
- Right channel only — keeps just the right channel, discarding the left.
Left/Right-only is useful when a stereo file actually holds two different mono sources on each side (a common trick in DI recordings), and Average is correct for everything else — kick drums, basslines, full mixes, and vocal takes.
Supported formats: WAV, MP3, FLAC, AAC & OGG to mono WAV
Audio to Mono accepts any format your browser can decode natively:
- WAV
- MP3
- FLAC
- AAC
- M4A
- OGG
- OPUS
- WebM
The output is always a standard 16-bit mono WAV, regardless of the source format or bit depth — so converting WAV to mono 16-bit or MP3 to mono online both land on the same clean, DAW-ready file.
Why convert stereo to mono?
Mono guarantees identical sound on every speaker — important for kick drums and basslines that need to hit the same way every time, for podcast or voice tracks played back on a single phone speaker, and for samples loaded into a sampler or drum machine that expects one channel. A mono file is also half the size of the equivalent stereo file.
Runs entirely in your browser — nothing uploaded
There's no server component to Audio to Mono. The file is read locally, decoded locally, mixed down locally, and written back out as a Blob you download directly — the same privacy guarantee as every Capsule Tools app.
Frequently asked questions
How do I convert stereo to mono online for free?
Open Audio to Mono, drop or choose your stereo file, and the browser mixes it down to a mono WAV instantly — no upload, no account. The decode and encode both run inside your browser tab, so the file never leaves your device.
How do I convert WAV to mono 16-bit?
Drop your WAV file onto Audio to Mono. The tool always outputs a standard 16-bit PCM mono WAV, regardless of the source file's bit depth or channel count, so converting WAV to mono 16-bit is the default behavior — no settings to configure.
Can I convert MP3 to mono online?
Yes. Audio to Mono accepts MP3 directly — the browser's built-in audio decoder handles it, then the tool mixes the decoded audio down to a single mono channel and hands back a mono WAV file, ready to download.
What does downmixing stereo to mono mean?
Downmixing stereo to mono means combining a file's separate left and right channels into a single channel. Audio to Mono's default Average method adds the left and right samples together and halves the result, which is the standard way to downmix stereo to mono without favoring either side.
What are the benefits of mono audio?
Mono audio guarantees the same sound on every speaker, which matters for kick drums and basslines that need to hit consistently, for voice and podcast tracks played on a single phone speaker, and for samples loaded into a sampler that expects one channel. It also halves the file size versus stereo.
Do I need Audacity or another DAW to convert stereo to mono?
No. Converting stereo to mono in Audacity, Logic, Premiere Pro, Audition, Ableton, or Pro Tools means opening the app, importing the file, and finding the right menu command. Audio to Mono does the same conversion in one browser tab, with no software to install.
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