Free - Browser-based or server-side encoding - LAME and FFmpeg

X Audio Converter

Convert WAV, MP3, FLAC, OGG, M4A, Opus and more audio formats - free. Choose browser-based encoding with LAME or FFmpeg WASM, or use our server-side FFmpeg 7 encoder for faster conversion and more output formats including Opus, WavPack, TTA and WAV. Also available as a free Windows desktop app.

LAME + FFmpeg Browser or server CBR & VBR ID3 tags MP3, OGG, Opus, FLAC, M4A, WAV Up to 320 kbps Windows app available
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LAME encoder

Click to select an audio file or drag it here

WAV, MP3, FLAC, OGG, M4A, AAC, WMA, AIFF, Opus - all sample rates

lame command lame -b 128 -m j input.wav output.mp3

Audio is processed locally in your browser - nothing is uploaded to any server.

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Windows desktop app

X Audio Converter for Windows

The same converter as a native Windows application. Uses lame.exe and ffmpeg.exe directly for maximum speed, full format support, and no browser memory limits.

Native lame.exe + ffmpeg.exe - 10-20x faster than browser encoding
WAV, MP3, FLAC, OGG, M4A, Opus, WavPack, TTA and more
CBR and VBR encoding, full ID3v2 tag support
No file size limits, works fully offline
100% free - no ads, no registration, no install wizard
Download X Audio Converter Free - Windows 7/8/10/11 - v1.0 - .exe

Also required

lame.exe
LAME MP3 encoder - static build required (no Visual C++ DLL).
Download from free-codecs.com
ffmpeg.exe optional
Enables non-WAV input and FFmpeg encoder mode for OGG, Opus, FLAC, M4A, WavPack and TTA output.
Download from free-codecs.com

Place both .exe files in the same folder as X-Audio-Converter.exe

X Audio Converter in action

Free browser-based and server-side audio conversion

X Audio Converter - free online audio converter with LAME and FFmpeg support, showing encoder selection, output format buttons and bitrate options
How it works

Convert audio to MP3, OGG, Opus, FLAC and more in three steps

01

Select your audio file

Click the upload area or drag and drop any supported audio file. WAV, MP3, FLAC, OGG, M4A, AAC, WMA, AIFF and Opus are all accepted. Browser modes never upload your file. Server modes send it encrypted over HTTPS for processing.

02

Choose encoder and output format

Pick browser LAME for instant MP3 without any upload, browser FFmpeg for MP3/OGG/FLAC/M4A without upload, or server FFmpeg for the full format range including Opus, WavPack and TTA at native FFmpeg 7 speed. Then set bitrate, CBR or VBR, and channel mode.

03

Download your converted file

Click Convert. Browser modes encode locally and show a download link instantly. Server mode uploads, converts with native FFmpeg 7, streams the result back, and deletes your file immediately. For batch encoding or very large files, use the free Windows app.

Encoder modes compared

Browser vs server vs Windows app

Browser (LAME / FFmpeg WASM)

Online - browser-based

  • No installation, no upload
  • Works on Windows, Mac and Linux
  • Files never leave your device
  • MP3, OGG, FLAC, M4A output
  • Slower than native encoding
  • FFmpeg WASM requires ~22 MB download
  • Single file at a time
Server (FFmpeg 7.0 native)

Online - server-side

  • Native FFmpeg 7 speed
  • Opus, WavPack, TTA, WAV output
  • No WASM download needed
  • Works on any device including mobile
  • File is uploaded to our server
  • 50 MB file size limit
Windows app

X Audio Converter for Windows

  • Fastest - native lame.exe + ffmpeg.exe
  • Full format support, no file size limit
  • Works fully offline
  • Full ID3v2 tag support
  • Windows only
  • Requires lame.exe download
Download free
FAQ

Frequently asked questions

What is the difference between browser and server encoding?
Browser-based encoding runs entirely in your browser - your audio file is never uploaded. Server-based encoding uploads your file to our server, runs native FFmpeg 7.0, and streams the converted result back. Server mode is faster, supports more output formats (Opus, WavPack, TTA, WAV), has no WASM download, and works on any device including mobile. Files uploaded for server encoding are deleted immediately after download.
What is the difference between LAME and FFmpeg encoder?
LAME is a lightweight MP3-only encoder - the best choice for quick WAV or FLAC to MP3 conversions. FFmpeg is a full-featured multimedia framework supporting MP3, OGG Vorbis, Opus, M4A, FLAC, WAV, WavPack and TTA. Use LAME for MP3 only; use FFmpeg for any other output format. Both are available as browser-based (no upload) and server-side (faster, native speed) options.
What audio formats can X Audio Converter handle?
Input: WAV, MP3, FLAC, OGG, M4A, AAC, WMA, AIFF and Opus. Output depends on encoder: MP3 only with LAME; MP3, OGG, FLAC and M4A with browser FFmpeg; MP3, OGG, Opus, M4A, FLAC, WAV, WavPack and TTA with server FFmpeg. The Windows desktop app supports all formats FFmpeg can handle.
Are uploaded files kept on your server?
No. For browser encoder modes nothing is ever uploaded. For server encoder modes, your file is uploaded over HTTPS, converted, streamed back, and deleted immediately. Any orphaned temp files from dropped connections are automatically removed after 4 hours by our cleanup system.
Which bitrate should I choose?
For MP3 music, 192 kbps CBR or VBR quality 2 is the standard recommendation. 128 kbps is fine for casual listening; 320 kbps is maximum quality. For Opus, 96-128 kbps sounds transparent - Opus is significantly more efficient than MP3 at the same bitrate. For voice and podcasts, 64-96 kbps mono is sufficient. FLAC, WAV and TTA are lossless so bitrate does not apply.
Does the Windows app require installation?
No. X Audio Converter for Windows is a single portable .exe file. Download it, place lame.exe in the same folder (and optionally ffmpeg.exe for additional formats), and run it. No installer, no admin rights, no registry entries.
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