MP3 to FLAC: what the conversion really gives you
This MP3 to FLAC converter decodes MP3 files and stores the result as FLAC, the open lossless format. It does exactly what it says: the FLAC holds the decoded MP3, sample for sample, and it will sound identical to the MP3. What it cannot do — and no converter can — is bring back the detail the MP3 encoder discarded when the file was made. A 128 kbps MP3 converted to FLAC is still a 128 kbps MP3 at heart, just in a much bigger file.
So why convert? Because sometimes the container matters more than the content. A music server or DJ library standardised on FLAC, a hi-fi streamer that sorts by format, an editing workflow that must not add another lossy generation, or a course that asks for FLAC files — all have good reasons to want FLAC even from an MP3 source. The conversion runs in your browser, so your files stay private.
How to use the MP3 to FLAC Converter
- Drop your MP3 files onto the upload area or click to select them.
- Leave Bit depth on “Match the source”, which makes 16-bit FLAC from MP3 — enough to hold everything an MP3 decoder produces. Choose 24-bit only if your software insists on it.
- Keep the Sample rate: resampling an MP3 to 96 kHz adds no information, only size.
- Press Convert to FLAC. Title, artist, album and cover art are copied into the FLAC’s Vorbis comments and picture block.
- Download each FLAC, or all of them as a ZIP.
MP3 to FLAC Converter features
True lossless storage
libFLAC encodes the decoded MP3 as 16-bit samples, and decoding the FLAC returns exactly those samples again.
16- or 24-bit
16-bit by default, matching CD audio; 24-bit available for software that requires it.
Tags and cover art
ID3v2 fields become Vorbis comments, and the front cover becomes a FLAC PICTURE block that music players show.
Honest file sizes
Each file shows the expected FLAC size before you convert, so the growth is no surprise.
Batch and ZIP
Convert a whole folder and download it as one archive.
Why a FLAC made from an MP3 is not “lossless quality”
MP3 encoding removes sound the encoder judges you won’t hear: quiet details masked by louder ones and, at lower bitrates, most content above about 16–17 kHz. Decoding produces an approximation of the original waveform, and that approximation is what the FLAC stores — perfectly. The result is lossless relative to the MP3, not to the recording the MP3 came from.
This is easy to check. Open the FLAC in a spectrum view such as the audio spectrogram: a FLAC ripped from a CD usually has content up to 20 kHz or beyond, while one made from a 128 kbps MP3 shows a hard ceiling around 16–17 kHz. Collectors call these “fake FLACs”, and many music communities reject them — so label converted files honestly.
How much bigger will the file be?
The FLAC’s size depends on the music, not on the MP3’s bitrate: the decoder always outputs a full 44.1 or 48 kHz signal, and FLAC compresses it like any other recording — typically to 50–70 % of a WAV. Quiet, sparse music compresses more; dense, loud mixes less.
| Source MP3 | FLAC (typical music) | Growth |
|---|---|---|
| 128 kbps | ≈ 700–1,000 kbps | 5–8 times |
| 192 kbps | ≈ 700–1,000 kbps | 4–5 times |
| 320 kbps | ≈ 700–1,000 kbps | 2–3 times |
Good reasons to convert anyway
- A library, media server or player profile that only accepts FLAC.
- An editing or archiving workflow where every intermediate file must be lossless, so the MP3 isn’t compressed a second time.
- Consistent tagging: Vorbis comments are simple, well supported and easy to edit in bulk.
- If you just need an uncompressed file for an editor, MP3 to WAV is the more widely supported choice; to go back the other way, use FLAC to MP3.
MP3 to FLAC Converter FAQ
Does converting MP3 to FLAC improve quality?
No. The FLAC is an exact copy of the decoded MP3, so it sounds the same. Lost detail can’t be recovered by any converter, whatever it claims.
How do I convert MP3 to FLAC?
Drop the MP3 on this page and press Convert to FLAC. Keep Bit depth on “Match the source” for a 16-bit FLAC.
Why is the FLAC so much larger than the MP3?
MP3 discards data to stay small; FLAC keeps every sample of the decoded audio and compresses it only losslessly, which typically lands at 2–8 times the size of the MP3.
Should I choose 16-bit or 24-bit?
16-bit. It already captures everything an MP3 decoder produces audibly, so 24-bit only makes the file bigger. Pick it only if software requires 24-bit input.
Will my tags and album art survive?
Yes. They are written as Vorbis comments and a FLAC picture block, which foobar2000, VLC, Kodi, Android players and most taggers read.
Can I spot a FLAC that was made from an MP3?
Usually. A spectrogram of such a file shows a sharp cut-off somewhere around 16–20 kHz, depending on the MP3’s bitrate, where a CD rip would extend further and fade naturally.