100% local and secure
Your data stays on your device and is never sent to our servers.
Audio converter
Convert MP3, WAV, OGG, Opus, WebM, M4A, AAC or FLAC files to MP3, WAV, FLAC, OGG, M4A or Opus without uploading the audio content to a server.
- 100% local
- Free
- No account
- Batch processing
- Workspace compatible
MP3, FLAC, OGG, M4A and Opus load FFmpeg/WASM on demand. The audio file remains processed locally in your browser.
Why use this tool?
Convert audio files locally to MP3, WAV, FLAC, OGG, M4A or Opus. The engine uses Web Audio for WAV when possible and loads FFmpeg/WASM only when the requested format or decoding requires it.
Smart processing
Generate, convert, or validate technical data with purpose-built controls.
Supported formats
Technical formats and syntaxes suited to each generator, converter, or validator.
Save time
Get a clean, ready-to-use result in seconds without installing software or configuring a complex workflow.
Fonctionnement
How does this tool work?
The file remains in your browser. For WAV, Bethemesh prefers Web Audio decoding followed by local PCM encoding. For MP3, FLAC, OGG, M4A and Opus, FFmpeg/WASM is loaded on demand in a Worker and performs the conversion without uploading media to a server. The first FFmpeg-powered conversion can therefore take a little longer to start.
Use cases
MP3 for sharing
Convert audio to MP3 for a widely compatible format with a practical file size.
Lossless FLAC
Create a FLAC file when you want to preserve audio quality without destructive compression.
Batch processing
Reuse the same conversion in Workspace across multiple audio files with one common output format.
Guide
How to use this tool
- 1
Choose a file
Import an audio file supported by the browser or FFmpeg/WASM.
- 2
Choose the format
Select MP3, WAV, FLAC, OGG, M4A or Opus for your target use.
- 3
Convert and download
The file is converted locally and then downloaded to your device.
Tips and best practices
- MP3 is a useful compromise between size, quality and compatibility.
- FLAC preserves audio data losslessly but usually creates larger files.
- The first MP3, FLAC or OGG operation must load the FFmpeg/WASM core before conversion.
Frequently asked questions
Is the audio file uploaded to a server?
No. Audio content remains processed locally in your browser.
Why can the first MP3 or FLAC conversion take longer?
FFmpeg/WASM is deliberately loaded on demand so the rest of the site stays lightweight.
Which output formats are available?
This POC converter offers MP3, WAV PCM, FLAC and OGG Vorbis.
Was this tool useful?
Read next
GuideFormatsIntermediate
Audio compression: bitrate, format and quality
Learn how bitrate, lossy and lossless compression affect audio quality and file size, and choose sensible settings for distribution.
30 August 20262 minRead
TutorialBest practicesIntermediate
Create an audio workflow with Workspace and pipelines
Combine trimming, channels, sample rate, normalization, compression and export into a clear, reusable audio processing pipeline.
30 August 20262 minRead
GuideFormatsBeginner
MP3, WAV, FLAC, OGG, Opus and M4A: which audio format should you choose?
Compare common audio formats, compatibility, compression and typical uses to choose the right working, archive or distribution format.
30 August 20262 minRead
GuideBest practicesBeginner
Convert and edit audio files directly in your browser
Convert, trim, adjust volume and merge MP3, WAV, FLAC, OGG, M4A or Opus files, then combine these operations in a pipeline.
29 August 20262 minRead
Recommended workflow
Continue your processing
Discover tools that naturally fit before, after, or alongside this one.
Complementary tools
Audio
Convert WAV to MP3
Convert a WAV file to MP3 locally in your browser.
100% localNew
Use this toolAudio
Convert M4A to MP3
Convert an M4A file to MP3 locally in your browser.
100% localNew
Use this toolAudio
Convert MP3 to WAV
Convert an MP3 file to WAV PCM locally in your browser.
100% localNew
Use this tool