How to convert mp3 to a different bitrate — browser tool
- Step 1Open the converter — Open the bitrate-changer in any modern browser. FFmpeg 8.1 loads into the page automatically on first use.
- Step 2Drop your MP3 — Drag the MP3 onto the dropzone. (WAV, FLAC, M4A, OGG, Opus, and video are accepted too, but the output is always MP3.) Free tier: 50 MB / 30 min.
- Step 3Choose the new bitrate — Pick from 320, 256, 192 (default), 128, or 64 kbps. Lower for smaller files; match the source for a clean re-tag without size change.
- Step 4Convert in-page — Click to process. FFmpeg re-encodes the MP3 locally at the new CBR — no upload, so short files finish quickly.
- Step 5Check tags carried over — The new MP3 keeps title, artist, album, and cover art. Confirm they display correctly in your player.
- Step 6Download the result — Save the re-encoded MP3. It is a standard CBR file that plays in any player and on any device.
Browser converter vs. desktop software
Why an in-browser FFmpeg WASM converter is convenient for one-off MP3 bitrate jobs.
| Aspect | This browser tool | Desktop app (Audacity / CLI FFmpeg) |
|---|---|---|
| Install required | None | Yes — download and install |
| Engine | FFmpeg 8.1 (libmp3lame) WASM | FFmpeg / LAME locally |
| Upload | None — runs in-tab | N/A (local) but needs the app |
| Bitrate options | 320 / 256 / 192 / 128 / 64 kbps | Any value you configure |
| Output format | MP3 only | Configurable |
| VBR support | No (CBR only) | Yes, if configured |
MP3 bitrate reference
The five available targets with their dropdown labels and typical roles. Per-minute sizes are approximate CBR.
| Dropdown label | Bitrate | Per minute | Typical role |
|---|---|---|---|
| 320 kbps · best | 320 kbps | ~2.4 MB | Highest MP3 quality |
| 256 kbps | 256 kbps | ~1.9 MB | High-quality music |
| 192 kbps · default | 192 kbps | ~1.4 MB | Balanced default |
| 128 kbps · podcast | 128 kbps | ~0.96 MB | Streaming / podcast |
| 64 kbps · voice | 64 kbps | ~0.48 MB | Spoken word |
Cookbook
Quick, no-install MP3 bitrate conversions done entirely in the browser. Each shows the dropdown choice and the resulting file.
320 kbps to 192 kbps in one click
A common request: shave a 320 kbps file to 192 kbps for a smaller library without a desktop app.
Input: song.mp3 320 kbps 3:30 ~8.4 MB Dropdown: '192 kbps · default' Output: song.mp3 192 kbps 3:30 ~5.0 MB
Re-tag without changing quality (same bitrate)
If you only need a fresh ID3v2.3 header on a 192 kbps file, re-encode at 192 kbps — tags are rewritten and the file stays similar in size.
Input: old.mp3 192 kbps [legacy tags] Dropdown: '192 kbps · default' Output: old.mp3 192 kbps [ID3v2.3 tags + cover preserved]
Convert a downloaded M4A to a 128 kbps MP3
Some players prefer MP3. Drop the M4A and the converter outputs an MP3 at your chosen bitrate.
Input: podcast.m4a ~128 kbps AAC 40:00 Dropdown: '128 kbps · podcast' Output: podcast.mp3 128 kbps 40:00 ~37 MB
Quick voice conversion to 64 kbps
A short voice clip dropped to 64 kbps for a tiny, shareable MP3 — done in seconds because nothing uploads.
Input: note.mp3 192 kbps 1:30 Dropdown: '64 kbps · voice' Output: note.mp3 64 kbps 1:30 ~0.72 MB
What this converter will not do
It cannot output VBR or a non-MP3 format, and it cannot upscale quality. Use the right sibling tool when you need those.
Want VBR? -> not supported (CBR only) Want WAV out? -> use a WAV converter, not this tool Want exact MB? -> use [audio-compressor](/audio-tools/audio-compressor) Want higher quality than source? -> impossible (lossy)
Edge cases and what actually happens
Expecting a desktop-style 'custom bitrate' field
By designThe browser tool offers five preset CBR values, not a free-text field. Pick the nearest target; for arbitrary bitrates, a desktop FFmpeg/LAME install is needed.
Dropping a WAV or M4A expecting the same format back
SupportedAny accepted input is re-encoded to MP3 — the converter has no format selector. The output extension is always .mp3.
Raising the bitrate to 'upgrade' an MP3
By designRe-encoding a 128 kbps MP3 at 320 kbps only enlarges it; the discarded detail cannot return. Match or lower the bitrate for a meaningful change.
Wanting VBR like the desktop LAME presets
Not supportedThis converter writes CBR via -b:a. VBR (e.g. LAME -V settings) is not available in the browser tool.
FFmpeg core still loading on first use
ExpectedThe first conversion in a session waits briefly while the FFmpeg WASM core loads into the page. Subsequent conversions reuse the loaded engine and start immediately.
File over 50 MB on the free tier
Tier limitFree caps input at 50 MB / 30 min. A long, high-bitrate MP3 may exceed this; trim it first or upgrade to Pro (200 MB / 120 min).
Tags not showing in the player
PreservedTags are written as ID3v2.3 and cover art is re-attached. If a player shows nothing, it may not read ID3v2.3 or the source had no tags.
Browser without the needed WASM features
ErrorVery old browsers may lack the WebAssembly features FFmpeg needs. Use a current version of Chrome, Edge, Firefox, or Safari.
Long file feels slow in the browser
ExpectedLocal CPU does the re-encode, so long files take real time. Short clips are near-instant because there is no upload. Pro can use multi-threaded FFmpeg when the browser is cross-origin isolated.
Frequently asked questions
Do I need to install anything?
No. The converter runs FFmpeg 8.1 as WebAssembly inside the browser tab — no desktop app, no plugin, no admin rights needed.
Is my MP3 uploaded?
No. Processing is fully local in your browser; the file is never sent to a server.
Which bitrates are available?
320, 256, 192 (default), 128, and 64 kbps, all constant bitrate.
Can I enter a custom bitrate like 160 kbps?
No. The browser tool offers five preset values. For arbitrary bitrates you would need a desktop FFmpeg/LAME install.
What format does it output?
Always MP3, even if you drop in a WAV, FLAC, M4A, OGG, or Opus file. There is no format selector.
Does it support VBR?
No. It writes constant bitrate (CBR) only; VBR presets are not available in the browser tool.
Will my tags and cover art survive?
Yes. ID3 tags are rewritten as ID3v2.3 and cover art is re-attached during the conversion.
Can I improve quality by converting to a higher bitrate?
No. Raising the bitrate of an existing MP3 does not recover lost detail; it only makes the file bigger.
Why is the first conversion a little slower?
The FFmpeg WASM core loads into the page on first use. After that it stays loaded and conversions start immediately.
What is the size limit?
Free: 50 MB / 30 min / 1 file. Pro: 200 MB / 120 min / 10 files. Pro-media and Developer: up to 100 GB with no duration cap.
Which browsers work?
Any current Chrome, Edge, Firefox, or Safari with WebAssembly support. Very old browsers may not run the FFmpeg core.
Can I convert several MP3s at once?
Free tier is one file per run; Pro allows up to 10 files per run. For an exact size target per file, use audio-compressor.
Privacy first
Every JAD Audio tool runs entirely in your browser via FFmpeg (WebAssembly) and RNNoise. Your audio files never leave your device — verified by zero outbound network requests during processing.