Convert audio
MP3, WAV, OGG, M4A, and FLAC. Powered by FFmpeg running locally in your browser - nothing is uploaded.
About this tool
Convert audio files between MP3, WAV, M4A (AAC), FLAC, OGG, Opus and more - all in your browser via FFmpeg compiled to WebAssembly. Useful for podcasts that arrived in the wrong format, voice memos you want to email, sample libraries that need to play in older software, and re-encoding tracks for cars or stereos that still refuse to read anything beyond MP3.
Each format has a job it's best at. MP3 is the universal default - it plays anywhere, in any decade of hardware. AAC (M4A) is the modern lossy default, smaller than MP3 at the same quality, and what most streaming services and Apple devices use natively. FLAC is the archival pick: lossless, smaller than WAV, and supported by every serious audio player. Opus and OGG Vorbis are excellent for voice and low-bitrate use cases, especially calls and podcasts.
Conversion happens entirely on your device - the file is read into memory, FFmpeg transcodes it, and you get the result back as a download. Nothing is uploaded, nothing is logged, and metadata like title, artist and album is carried across when both source and target formats support it.
Features
- MP3, WAV, OGG, M4A (AAC), FLAC, Opus
- Adjustable bitrate or quality per format
- Preserves ID3 / Vorbis comment metadata when possible
- Batch convert multiple files at once
- Download individually or as a ZIP
- Works offline after the first page load
How to use it
- Drop your audio files onto the page.
- Pick the output format.
- Optionally set a quality or bitrate target.
- Click Convert and wait while FFmpeg processes locally.
- Download the converted files individually or as a ZIP.
Everything happens inside your browser using JavaScript and WebAssembly. Your files are never uploaded to a server, never stored, and never seen by us.
Frequently asked questions
FLAC for archival or original-quality copies (lossless). MP3 320 kbps or AAC 256 kbps for portable listening - both are transparent for most ears at those bitrates and play on essentially everything. Opus at 128 kbps beats both for voice.
Title, artist, album, year and track number are transferred when both source and target support them. Album art is preserved between MP3, M4A and FLAC; some less common combinations drop it.
FLAC is lossless - every audio sample is preserved. MP3 throws away frequencies the ear can't easily hear in order to shrink the file. The conversion is one-way: you can't recover the discarded data by converting MP3 back to FLAC later.
Yes. FFmpeg is the same engine most desktop audio tools use under the hood. The browser version is the exact same code compiled to WebAssembly - bit-for-bit identical results.