Convertio.com

MP3 to FLAC Converter

Convert MP3 to FLAC format online for free. Wraps MP3 audio in a lossless FLAC container for library consistency and archival. Note: does not improve audio quality. Up to 100 MB.

256-bit SSL 4.9 rating Files auto-deleted in 2h

Tap to choose your MP3 file

or

Also supports M4A, AAC, OGG, OPUS, WMA • Max 100 MB

Your files are secure. All uploads encrypted via HTTPS. Files automatically deleted within 2 hours.

How to Convert MP3 to FLAC

1

Upload

Drag and drop your MP3 file into the converter above, or click Choose MP3 File to browse your device.

2

Convert

Click Convert to FLAC. The MP3 is decoded and the audio is stored in a lossless FLAC container.

3

Download

Click Download FLAC to save the file. Note: the output will be larger than the MP3, but quality remains unchanged.

Important: Converting MP3 to FLAC does not improve audio quality. MP3 is a lossy format — data discarded during MP3 compression cannot be recovered. The FLAC output preserves the decoded MP3 audio in a lossless container, but the original lossy artifacts remain.

How to Convert MP3 to FLAC on Every Platform

Windows

foobar2000 is a free, lightweight player with a built-in converter. Open your MP3 files, right-click, select "Convert," and choose FLAC as output format. dBpoweramp offers batch conversion with a clean interface. For bulk libraries, fre:ac is an open-source batch converter.

macOS

XLD (X Lossless Decoder) is the standard tool for audio conversion on Mac. Drag MP3 files into XLD and convert to FLAC. fre:ac also runs on macOS. For command-line users, ffmpeg handles the conversion: ffmpeg -i input.mp3 output.flac

Linux

ffmpeg is the standard tool: ffmpeg -i input.mp3 output.flac. For batch conversion, SoundConverter provides a GUI, and fre:ac is available as a Flatpak. You can also script batch conversions with a simple bash loop using ffmpeg.

Online (any device)

Use our converter above — works on any device with a web browser. No software installation needed. Upload your MP3, convert, and download the FLAC. Supports files up to 100 MB.

What is MP3?

MP3 (MPEG-1 Audio Layer III) is the most widely used lossy audio format. Developed in the early 1990s, it achieves compression ratios of 10:1 or more by discarding audio data that is perceptually less important. At 320 kbps, MP3 files are approximately 2.4 MB per minute.

MP3 is universally supported — every device, player, and operating system handles MP3 files natively. The tradeoff is that data discarded during encoding is permanently lost and cannot be recovered by converting to a different format.

What is FLAC?

FLAC (Free Lossless Audio Codec) is an open-source lossless audio format. It compresses audio to 50–60% of the original size without discarding any data. FLAC supports metadata tags, cover art, cue sheets, and ReplayGain.

FLAC is supported by most modern players, phones, and streaming services (Tidal, Qobuz, Amazon Music HD). It is the standard format for lossless music libraries and audiophile collections.

MP3 vs FLAC: Quick Comparison

FeatureMP3FLAC
Compression typeLossyLossless
QualityDegraded (data discarded)Bit-perfect (no data loss)
File size (4 min song)~8 MB (320 kbps)~25 MB (from CD source)
Metadata supportID3 tags, cover artVorbis comments, cover art, cue sheets
Device compatibilityUniversalMost modern devices
Streaming servicesSpotify, YouTube MusicTidal, Qobuz, Amazon Music HD
Best forPortable listening, sharingArchival, lossless libraries

Why Convert MP3 to FLAC?

Prevent further quality loss

If you need to re-encode audio later (different bitrate, different format), starting from a FLAC preserves the decoded MP3 audio exactly. Re-encoding an MP3 to another MP3 introduces generation loss — each lossy-to-lossy conversion degrades quality further. FLAC acts as a lossless "snapshot" of the decoded audio.

Library consistency

If you maintain an all-FLAC music library, converting your MP3 files to FLAC keeps your collection in a single format. This simplifies backup, player configuration, and metadata management.

Player compatibility

Some dedicated music players and streamers work best with FLAC. Converting your MP3 collection to FLAC ensures compatibility with FLAC-focused hardware and software.

Metadata and tagging

FLAC's Vorbis Comments tagging system is more robust than MP3's ID3 tags. FLAC supports arbitrary key-value pairs, multiple embedded images, cue sheets, and ReplayGain natively. Converting to FLAC gives access to better metadata tools.

Frequently Asked Questions

No. FLAC losslessly preserves whatever audio data is provided. Since the MP3 has already discarded data during compression, the FLAC simply stores the degraded audio in a larger container. No lost information is recovered. The output sounds identical to the MP3 input.
The MP3 is decoded to raw PCM audio during conversion, then FLAC losslessly compresses that PCM data. Lossy MP3 compression is much more aggressive than lossless FLAC compression, so the FLAC is typically 3–5x larger. The audio content is identical.
Yes. FLAC prevents further generation loss if you need to re-encode later. It also helps with library consistency (all-FLAC collections), compatibility with FLAC-focused players, and access to better metadata and tagging tools.
Yes. A spectral analysis will show the frequency cutoff from MP3 encoding (typically a sharp rolloff at 16–20 kHz depending on bitrate). Tools like Spek or Audacity can reveal this. A genuine lossless FLAC from a CD source shows frequencies up to 22.05 kHz with no artificial cutoff.
Yes. Convertio.com offers free MP3 to FLAC conversion with no watermarks, no registration, and no email required. Files are encrypted during transfer and auto-deleted within 2 hours.

MP3 to FLAC Guides

Related Audio Conversions