Lossless baseline for further work.
FLAC preserves every detail of the source MP3, which prevents additional quality loss during subsequent edits or re-encoding. The original MP3 compression cannot be undone, but no new artifacts will be introduced.
WHY CONVERT
01
FLAC preserves every detail of the source MP3, which prevents additional quality loss during subsequent edits or re-encoding. The original MP3 compression cannot be undone, but no new artifacts will be introduced.
02
FLAC is accepted by a wider range of audio players, car stereos, and streaming services than MP3. The conversion removes a recurring compatibility friction without changing what the file actually contains.
03
FLAC files are typically smaller than their MP3 counterparts, which reduces hosting, transfer, and storage costs at scale. The savings compound when serving the same content to many recipients.
Visit this page on any modern browser — no install, no signup, no plugin.
Drag your MP3 into the drop area, or click to pick one from your device.
Conversion runs entirely in your browser. When it's done, your FLAC file downloads to your device.
QUALITY & FIDELITY
FORMAT SPECS
| MP3 | FLAC | |
|---|---|---|
| Extensions | .mp3 | .flac |
| MIME types | audio/mpeg | audio/flac audio/x-flac |
| Introduced | 1993 | 2001 |
| Maintainer | ISO/IEC (MPEG) | Xiph.Org Foundation |
| Magic # | 49 44 33 | 66 4C 61 43 |
| Spec | View spec ↗ | View spec ↗ |
COMPATIBILITY
| Platform | Windows | macOS | iOS | Android | Chrome | Firefox | Safari | Edge |
|---|---|---|---|---|---|---|---|---|
| MP3 | Native | Native | Native | Native | Native | Native | Native | Native |
| FLAC | Native | Native | Native | Native | Native | Native | Native | Native |
Why LocalConvert
| Category | LocalConvert | Cloud converters |
|---|---|---|
| PRIVACY | Files never leave your device. The whole pipeline runs in your browser via WebAssembly. | Files travel to a remote server, sit in queue storage, and may be retained for analytics or moderation. |
| COST | Free, no signup, no daily quotas. | Often free for small files; paid tiers for batch / large / commercial use. |
| LIMITS | Limited only by your device's memory and CPU. Uncompressed WAV stems handled comfortably on desktop. | Typical 100 MB to 1 GB per-file caps, plus rate limits. |
The world's most ubiquitous lossy audio format. Universal compatibility, modest file sizes, good quality at 192 kbps and above.
Typical uses
Music libraries, podcasts, streaming, sharing.
A lossless audio format that reduces file size ~40–60% versus WAV with bit-perfect playback.
Typical uses
Audiophile libraries, music archives, hi-res audio.
Yes. LocalConvert is completely free, with no signup and no per-file or per-day limits.
No. MP3 to FLAC conversion happens entirely inside your browser using WebAssembly — your file never leaves your device.
There's no fixed cap — the practical limit is your device's available memory. Very large files may take longer or fail on low-RAM devices.
Yes — once the page has loaded, MP3 to FLAC conversion works without an internet connection. Re-open the page once to cache it.
LocalConvert uses the industry-standard tools (FFmpeg, ImageMagick, Pandoc) — quality matches what professionals use on the command line. Lossy formats will still lose some quality on each re-encode.
Last verified:
MP3 to FLAC is processed in your browser with WebAssembly. No upload, no tracking, no limits. Your file never leaves your device.