Convert FLAC to MP3
Turn lossless FLAC albums into MP3 for phones and car stereos. Batch queue, up to 320 kbps, and nothing ever leaves your computer.
- Runs in your browser
- Files are never uploaded
- Free, no account
First use downloads the 10 MB video engine from this site. After that it is cached and works offline. It is WebAssembly served by onthisdevice.com — never a third-party CDN — and your file is still processed entirely on your own device.
The one conversion where bitrate is entirely your choice
Most lossy-to-lossy conversions force your hand: encode below the source bitrate and you stack artefacts, encode above it and you waste space on information that was already discarded. FLAC is different. It is mathematically lossless — decode it and you get back the original samples, bit for bit — so the MP3 encoder is working from a pristine master. Whatever bitrate you choose is the only lossy step in the chain.
What each setting costs and saves
Figures below are for a five-minute stereo track ripped from CD, which is roughly 50 MB as WAV and 30 MB as FLAC.
| MP3 setting | Track size | 12-track album | Verdict |
|---|---|---|---|
| 320 kbps | ≈ 12 MB | ≈ 144 MB | Transparent to nearly everyone, on nearly any system |
| 256 kbps | ≈ 9.6 MB | ≈ 115 MB | Very close; 20% smaller for a difference few can pick out |
| 192 kbps | ≈ 7.2 MB | ≈ 86 MB | The sensible phone and car default |
| 128 kbps | ≈ 4.8 MB | ≈ 58 MB | Audible on cymbals and applause through good headphones |
Note what is not in that table: any suggestion that going higher than 320 kbps is possible. That is the MP3 format’s ceiling. If you want better than 320 kbps MP3, the answer is to keep the FLAC.
How much does FLAC actually compress?
FLAC uses linear prediction and Rice coding — it models each sample from the ones before it and stores only the residual. On typical CD-rate music that gets you to 55–65% of the WAV size with no loss at all. Dense, loud, heavily limited modern masters compress worst (around 70%); sparse acoustic recordings and classical music with real dynamic range compress best (sometimes under 50%). Nothing about the compression level a ripper used affects the decoded audio — it only changed how long the encode took.
Why people convert their FLAC library
- Phone storage. A 400 GB FLAC library becomes 90 GB at 192 kbps, which is the difference between fitting on the device and not.
- Car head units. A great many read MP3 from USB and nothing else, or read FLAC only from certain filesystems.
- DJ software and gym equipment. Both are conservative about formats.
- Sharing. A 30 MB track is awkward to send; a 7 MB one is not.
The right approach is almost always to keep the FLAC as your archive and treat the MP3s as a disposable copy you can regenerate at any time. That way a future device with more storage — or a better codec — costs you nothing.
Tags and album art
FLAC uses Vorbis comments plus a dedicated picture block. FFmpeg maps the standard fields onto ID3v2.3, so title, artist, album, album artist, date, track number, disc number and genre come across intact. Embedded cover art usually survives; very large images, unusual picture types such as "back cover" or "artist photo", and multiple images per file may not. Rich fields that only exist in the Vorbis world — MusicBrainz identifiers, ReplayGain values, arbitrary custom keys — have no ID3v2.3 equivalent and are dropped.
Converting an entire album locally
Select every track at once. Up to fifty files queue at a time, converting one after another with an individual progress row, and the finished set can be downloaded as a single ZIP. A whole album takes well under a minute on a modern laptop.
This is the case that upload converters handle worst: twenty files, 300 MB, and free tiers that cap you at two files an hour or 100 MB per upload. Here the encoding happens on your own processor, so the only ceiling is your device — and your library never travels anywhere.
Related tools
Need an uncompressed master for an editor or sampler instead? Use MP3 to WAV or start from the FLAC in a desktop editor. Compressing large recordings you made yourself is covered by WAV to MP3, and the general audio converter handles any other format pair.
Questions
What bitrate should I use for a FLAC album?
Because FLAC is lossless there is no generation loss to worry about on the way in, so the MP3 setting is purely your own quality-versus-size call. 320 kbps for a good pair of headphones, 256 kbps for a very close match at 20% less space, 192 kbps for a phone or car where road noise dominates anyway.
How much smaller will the files get?
FLAC typically compresses CD audio to 55–65% of WAV, roughly 30 MB for a five-minute track. The same track at 320 kbps MP3 is about 12 MB and at 192 kbps about 7 MB — so expect a whole album to shrink from around 300 MB to 70–120 MB. The tool shows the exact ratio when it finishes.
Can I convert a whole album in one go?
Yes — select every track, and the queue works through them in order with a progress bar each, then offers one ZIP. There is no per-day cap and no 100 MB per-file limit, because your own CPU is doing the encoding.
Will the album art and track numbers carry over?
FFmpeg maps FLAC’s Vorbis comments onto ID3v2.3 tags, so title, artist, album and track number normally survive. Embedded cover art usually does too, though very large images and unusual picture types can be dropped.