How to Convert FLAC to MP3 — Free Online Guide
You've downloaded a lossless FLAC album. Your phone won't play it. Your car stereo doesn't recognise the format. Your music streaming upload rejected it. You need MP3s.
Converting FLAC to MP3 is one of those conversions that audiophiles argue about endlessly — but the practical answer is simpler than the debate suggests. This guide explains exactly what happens to the audio, which bitrate to choose, and the fastest free ways to do it.
Quick answer: Converting FLAC to MP3 trades lossless quality for universal compatibility. Use 320 kbps for near-transparent quality, 192 kbps for a good balance of size and fidelity. Use Convertlo's FLAC to MP3 converter — runs in-browser, no upload, keeps the original FLAC untouched.
FLAC vs MP3 — The Quality Difference Explained
FLAC (Free Lossless Audio Codec) compresses audio without discarding any data. Like a ZIP file for audio, it reduces file size by 40–60% while preserving every bit of the original signal. Decompressing FLAC produces a bit-perfect copy of the source recording.
MP3 uses psychoacoustic modeling to discard audio information that human hearing is least likely to notice: very high frequencies, quiet sounds masked by loud ones, stereo detail in high-frequency content. The result is a much smaller file that sounds perceptually similar — but is not mathematically identical — to the original.
The practical conclusion: if you're archiving music, keep the FLAC. If you need files that play on your phone, car, or old iPod, 320 kbps MP3 is excellent quality that works everywhere.
Why Convert FLAC to MP3?
- Compatibility — FLAC is not supported natively in iTunes/Apple Music, on most smart TVs, car head units manufactured before ~2018, or on iOS without third-party apps. MP3 plays on literally every device made since 1998.
- File size — A high-resolution FLAC album (24-bit/96 kHz) can be 500 MB to 2 GB. At 320 kbps MP3, the same album fits in under 150 MB — small enough to carry your entire collection on a phone.
- Streaming and sharing — Platforms like SoundCloud accept MP3. Sending a large FLAC to a friend over email is impractical; a 320 kbps MP3 is a fraction of the size.
- Car audio — Many factory and aftermarket head units play MP3 from USB but don't support FLAC.
Convert FLAC to MP3 Free — Right Now
No upload, no software, no signup. Your file never leaves your device.
Method 1 — Convert FLAC to MP3 Free in Your Browser
- Open convertlo.pro/flac-to-mp3.html on any device.
- Drag and drop your FLAC file (or multiple files for batch conversion).
- On first use, the browser downloads FFmpeg.wasm (~32 MB) — cached after first use.
- Conversion runs 100% locally — your audio never leaves your device.
- Click Download to save the MP3 file.
Works on Chrome, Edge, Firefox, and Safari. Handles FLAC, WAV, AIFF, M4A, OGG, and more. Batch conversion available.
Method 2 — Convert Using FFmpeg (Command Line)
- Install FFmpeg from ffmpeg.org or via
brew install ffmpegon Mac. - Open Terminal or Command Prompt.
- Convert a single file at 320 kbps:
ffmpeg -i input.flac -b:a 320k output.mp3
Batch convert an entire album folder:
for f in *.flac; do ffmpeg -i "$f" -b:a 320k "${f%.flac}.mp3"; done
To preserve album metadata (artist, title, track number) add -map_metadata 0 to the command. FFmpeg copies FLAC metadata to ID3 tags automatically in most cases.
Method 3 — Convert Using fre:ac (Free Audio Converter)
- Download fre:ac free from freac.org (open source, no ads).
- Drag your FLAC files into the converter window. You can add an entire album at once.
- In the encoder dropdown, select LAME MP3 Encoder.
- Set quality to 320 kbps (or use ABR 192 kbps for smaller files).
- Click the green Play button to start conversion.
fre:ac is excellent for batch converting large FLAC libraries. It preserves all metadata including album art, which is important for music libraries.
FLAC vs MP3 — File Size and Quality Comparison
| Format | 4-min song | Quality | Plays on |
|---|---|---|---|
| FLAC (16-bit/44.1 kHz) | ~25 MB | Lossless | Limited |
| FLAC (24-bit/96 kHz) | ~80 MB | Lossless Hi-Res | Very limited |
| MP3 192 kbps | ~5.5 MB | Very good | Everything |
| MP3 320 kbps | ~9 MB | Near-transparent | Everything |
| AAC 256 kbps | ~7.5 MB | Better than 256 kbps MP3 | Most modern devices |
Should I Use MP3 or AAC?
If your goal is maximum compatibility, MP3 wins — it plays on every device without exception. If your goal is best quality at the smallest size and your target devices are modern (iPhone, Android, macOS, Windows 10+), AAC 256 kbps is technically better than MP3 320 kbps — the same perceived quality at a smaller file size.
Convertlo supports both formats. Convert to FLAC to AAC if you're building an Apple Music library, or stick with MP3 for universal playback.