Audio Format Converter — MP3, WAV, OGG, FLAC, M4A
Convert audio to MP3, M4A, AAC, OGG, Opus, FLAC or WAV with a chosen bitrate on our server (free Google sign-in), or to WAV and WebM in your browser with no upload.
About Audio Format Converter
An audio format converter transcodes a file from one audio format to another — MP3 ↔ WAV ↔ OGG ↔ FLAC ↔ M4A / AAC — so it matches what a destination accepts (a podcast platform, an audio editor, a lossless archive). The ZTools Audio Format Converter has two modes. On this device, it decodes the file with the Web Audio API and saves it as WAV (16- or 24-bit) or as the compressed format your browser can record (usually WebM, sometimes Ogg or M4A); nothing is uploaded. On our server, ffmpeg converts it to MP3, M4A, AAC, OGG, Opus, FLAC or WAV at 96 to 320 kbps, in mono or stereo, with an optional trim, and can take the sound out of a video. The server mode needs a free Google sign-in and deletes your file right after processing.
Use cases
- Podcast platform requirements. Some platforms accept only MP3 at specific bitrates. Recorded in WAV; convert to MP3 at 128 kbps stereo before upload.
- Phone ringtone format. iOS expects M4R / M4A; Android accepts MP3 / OGG. Convert your trimmed clip to the target format.
- Lossless archive. Originally lossless WAV → FLAC shrinks the file without losing any quality, which suits an archive.
- Compatibility with old devices. Older car stereos may reject newer formats (Opus, AAC). Convert to MP3 for universal playback.
How it works
- Add an audio file. MP3, WAV, OGG, Opus, FLAC, AAC or M4A. The server mode also takes a video and keeps its sound; files up to 100 MB and 30 minutes.
- Choose where to convert. "On this device" converts in your browser with no upload. "On our server" offers every format below and needs a free Google sign-in.
- Pick the target format. MP3 (universal lossy), WAV (universal lossless, large), OGG and Opus (open lossy), FLAC (open lossless), M4A / AAC (Apple-friendly lossy).
- Pick bitrate and channels. Voice: 96-128 kbps. Music: 192-256 kbps. Lossless formats have no bitrate setting. Choose mono for voice-only recordings.
- Download. The converted file downloads with the new extension.
Examples
Input: 50 MB WAV (CD-quality, 5 min) → MP3 192 kbps
Output: ~7 MB MP3. Transparent for music; 7x size reduction.
Input: MP3 at 128 kbps → WAV
Output: WAV is larger (~10x) but does not regain lost quality. Lossy → lossless does not undo prior compression.
Input: WAV → FLAC
Output: Same audio quality in a noticeably smaller file. Useful for archives.
Frequently asked questions
What is the difference between lossy and lossless?
Lossless (WAV, FLAC, ALAC): bit-perfect reconstruction; large files. Lossy (MP3, AAC, OGG, OPUS): smaller files via psychoacoustic discarding; quality grades by bitrate.
Why does MP3 → MP3 lose quality?
Decoding to PCM and re-encoding goes through the lossy codec twice. Generation loss compounds. Avoid re-encoding lossy → same lossy when possible.
What bitrate is "transparent"?
For voice: 96 kbps MP3 / 64 kbps OPUS is transparent. For music: 192-256 kbps MP3 / 128-192 kbps AAC is transparent for most listeners. Above that = diminishing returns.
Should I use MP3 or AAC?
AAC at the same bitrate sounds noticeably better than MP3 (especially below 192 kbps). MP3 is more universally supported. iTunes / Apple ecosystem prefers AAC; legacy devices prefer MP3.
Why can the on-device mode not make MP3?
Browsers cannot encode MP3 by themselves. The on-device mode saves WAV or the compressed format your browser supports; use the server mode for MP3, FLAC, AAC and the rest.
Is the audio uploaded?
Only in the "On our server" mode, which sends it over HTTPS to our own processing server; the server deletes the file and the result right after processing. The "On this device" mode never uploads anything.
Pro tips
- Always work from the highest-quality source. WAV / FLAC source → MP3 export beats MP3 source → MP3 re-export.
- Match bitrate to content: 128 kbps suffices for podcasts; 192-256 kbps for music; 320 kbps only for high-fidelity needs.
- Use FLAC for personal archive, MP3 / AAC for sharing.
- Verify the output plays correctly — bitrate / sample-rate mismatches sometimes break older players.
- For voice content, Opus at 64 kbps is dramatically smaller than MP3 with no audible difference.
Reviewed by Ahsan Mahmood · Last updated 2026-09-11 · Part of ZTools.
For the full,
formatted version of this page, please enable JavaScript and reload
https://ztools.zaions.com/audio-format-converter.