Audio Tools
Audio Converter
Convert audio between MP3, WAV, OGG, FLAC, AAC, and OPUS formats with bitrate and sample rate control.
Your files stay on your device - processed locally via WebAssembly, never uploaded
Drop audio file or click to upload
MP3, WAV, OGG, FLAC, AAC, M4A, WebM, OPUS, WMA
Your audio files are processed in your browser. Nothing is uploaded to any server.
What is the best free audio converter online?
OptiPix Audio Converter converts MP3, WAV, OGG, FLAC, AAC, and OPUS in your browser using FFmpeg WebAssembly, with no upload and no file-size limit. Unlike CloudConvert or Online-Audio-Converter.com, there are no daily conversion limits and audio files never reach a server.
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Copy this code to add the Audio Converter to your site for free. It runs entirely in your visitors' browsers - no API key, no usage limits.
<iframe src="https://optipix.art/embed/audio-converter" width="100%" height="600" style="border:1px solid #e4e4e7;border-radius:8px;" title="Audio Converter by OptiPix" loading="lazy"></iframe> <p style="font-size:12px">Free tool by <a href="https://optipix.art/audio-converter">OptiPix Audio Converter</a></p>
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About Audio Converter
Last updated: May 2026
OptiPix Audio Converter transforms audio files between all major formats directly in your browser. Convert MP3, WAV, OGG, FLAC, AAC/M4A, WMA, AIFF, WebM, OPUS, and AMR files to your desired output format. Control bitrate (64-320 kbps), sample rate (22050-48000 Hz), and channels (mono/stereo). Batch convert multiple files at once. Uses FFmpeg.wasm for professional-grade encoding with no quality loss beyond the target format's characteristics. Estimated output file size shown before conversion. All processing happens locally - your audio files never leave your device.
How It Works
The converter uses FFmpeg.wasm to decode your input audio and re-encode it in the target format with your specified bitrate, sample rate, and channel settings. All processing runs locally in your browser.
Use Cases
- •Convert FLAC to MP3 for portable devices
- •Convert WAV to OGG for web embedding
- •Reduce file size by converting to a lossy format
- •Convert podcast audio to different distribution formats
- •Extract compatible audio for video editing software
You Might Also Like
If you find Audio Converter useful, check out these related tools: Audio Trimmer, Video to Audio Extractor, and Audio Volume Booster. All tools run entirely in your browser with no uploads or signups required.
Explore more: Browse all tools · Step-by-step guides · Tips & tutorials · Compare tools
OptiPix Audio Converter vs CloudConvert vs Online-Audio-Converter.com vs Zamzar
| Feature | OptiPix | CloudConvert | Online-Audio-Converter.com | Zamzar |
|---|---|---|---|---|
| Audio uploaded to a server | Never | Yes | Yes | Yes |
| Free conversion limit | Unlimited | 25/day free | Unlimited with ads | 2 files/day free |
| Formats | MP3, WAV, OGG, AAC, FLAC, M4A | 200+ formats | MP3, WAV, M4A, FLAC, OGG, AMR | 1200+ formats |
| Bitrate control | Yes | Yes | Yes | Limited |
| Wait time | None - converts instantly | Upload + queue | Upload + queue | Email delivery on free |
Competitor details reflect publicly listed free-tier features and may change.
Conversion pipeline details
Conversions run through FFmpeg compiled to WebAssembly, using the reference encoders for each format: LAME for MP3, the native AAC encoder for M4A/AAC, libvorbis for OGG, and FLAC's own lossless encoder. The output is identical to what a desktop FFmpeg install produces with the same settings.
Lossless-to-lossy conversion (FLAC or WAV to MP3/AAC) lets you pick the bitrate: 320kbps is transparent for almost all listeners, 192kbps is the streaming sweet spot, and 128kbps halves size again for voice content. Converting between two lossy formats (MP3 to AAC) always re-encodes and stacks generation loss, so start from the original whenever possible.
Because decoding and encoding happen in-tab, a typical 50MB WAV converts to MP3 in a few seconds with no upload. Interviews, demo recordings, and unreleased tracks never touch a third-party server - a hard requirement for journalists and musicians under embargo.
Frequently Asked Questions
What audio formats are supported?
Can I control the bitrate?
Can I convert to mono?
Is my audio uploaded?
Can I batch convert?
Which audio format has the best quality?
Does converting MP3 to WAV improve quality?
What bitrate should I use for MP3?
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