FLAC vs MP3: Is FLAC Really Better Than MP3?

FLAC and MP3 are the two music formats most people end up choosing between. FLAC keeps every bit of the original recording in a smaller package than WAV. MP3 goes further and removes sound details it expects you will not hear, so the files are much smaller still. This guide compares them on sound, size, device support and streaming, explains whether you can actually hear the difference, and shows which bitrate to pick when you need an MP3 from a FLAC.

The short answer

• FLAC is lossless. Decode it and you get back exactly the audio that went in.
• MP3 is lossy. It is about two to three times smaller than FLAC at its best setting, and much smaller at lower ones.
• The sound difference is smaller than the size difference. At 320 kbps, many listeners cannot pick the MP3 out in a blind test. At 128 kbps, many can.
• Keep FLAC as your master. You can always make an MP3 from it later, but you can never turn an MP3 back into the original.

FLAC vs MP3 at a glance

How each format works

FLAC stands for Free Lossless Audio Codec. It shrinks audio the way a ZIP file shrinks text, only far better, because it is built for sound. It predicts each sample from the ones before it and stores the small error in that prediction. Every FLAC file also stores a checksum of the original audio, so software can confirm a copy is exact. The format was published as an internet standard, RFC 9639, in December 2024.

MP3 works on a different idea. It uses a model of human hearing to decide what you are unlikely to notice: quiet sounds that sit right next to louder ones in pitch or in time. It spends few or no bits on those. The bitrate sets how much data it keeps each second, from 32 up to 320 kbps, which is the highest the MP3 standard allows. Whatever MP3 removes is gone for good.

File size compared

These figures are for stereo music in decimal megabytes. FLAC sizes vary with the music, because quiet, simple recordings compress better than loud, dense ones.

So a FLAC library is roughly two to three times the size of the same library as 320 kbps MP3, and five to eight times the size of 128 kbps MP3. On a large phone or a home server that may not matter. On a small phone, a USB stick for the car or a slow upload, it does.

Can you hear the difference?

This is the real question behind "is FLAC better than MP3", and the honest answer is that it depends on four things: the MP3 bitrate, the music, the equipment and your ears.

At 128 kbps, many people can hear the MP3 once they know what to listen for: swishy cymbals, a faint smear just before sharp drum hits, grainy reverb tails and fade-outs.

At 256 to 320 kbps, the gap is much smaller. Many listeners cannot reliably tell the MP3 from the FLAC in a blind test, especially on phone speakers, in a car or in a noisy room. Trained listeners with good headphones can sometimes hear differences on certain tracks, but fewer than claim to.

The difference is easiest to hear on:

• Quiet, sparse recordings such as solo piano, acoustic guitar and classical music
• Tracks full of cymbals, applause or long reverb
• Good wired headphones or speakers in a quiet room

It is hardest to hear over Bluetooth. Most Bluetooth headphones receive a lossy stream (SBC, AAC, aptX or LDAC), so a FLAC file is compressed again on its way to your ears. Our guide on whether lossless audio works over Bluetooth covers the details.

The only fair way to decide for yourself is a blind test. Make a 320 kbps MP3 from one of your FLAC files, match the volume, and use an ABX tool (foobar2000 has a free ABX Comparator) that plays them in random order and scores your guesses. If you cannot beat chance on your own gear, 320 kbps MP3 is good enough for your listening.

Tags, cover art and gapless playback

Both formats carry the information a music library needs. MP3 stores title, artist, album and cover art in ID3 tags; our guide to ID3 tags explains how they work. FLAC stores the same information as Vorbis comments and can embed cover art in the file. Most music players read both, so tags are rarely a reason to pick one format over the other.

Gapless playback is different. An MP3 encoder adds a short stretch of silence at the start of the file and some padding at the end, and the MP3 standard has no official way to record how much. On live albums and continuous DJ mixes that can mean tiny gaps between tracks, unless the encoder (LAME, for example) writes gapless information and your player reads it. FLAC stores the exact length of the audio, so tracks that should flow into each other do.

Hi-res FLAC: is 24-bit worth it?

FLAC can hold more than CD quality. Hi-res downloads often come as 24-bit files at 96 kHz or higher, which take about 3.3 times the space of the same music at CD quality (16-bit, 44.1 kHz). MP3 cannot carry that extra resolution at all.

Whether you can hear it is a separate question. In 2016, a review of 20 published listening tests in the Journal of the Audio Engineering Society found that listeners could tell hi-res from CD-quality audio slightly, but measurably, more often than chance, and that the effect was much stronger in trained listeners. Other researchers have pointed out that the overall result was only a little better than guessing. If you buy hi-res files, keep them as FLAC; for everyday listening, CD-quality FLAC or a good MP3 is enough for most people. Our sample rate guide explains what the higher numbers capture.

Where each format plays

MP3 plays on almost everything with a speaker: phones, computers, browsers, car stereos, smart TVs and old MP3 players.

FLAC plays on most modern systems:

• Windows has played FLAC natively since Windows 10.
• Mac has supported FLAC since macOS 10.13 High Sierra, but Apple's Music app and iTunes will not add FLAC files to your library. Convert them to Apple Lossless (ALAC) to keep full quality there.
• iPhone and iPad can play FLAC from iOS 11 on, for example from the Files app, but not inside the Music app.
• Android has supported FLAC since Android 3.1.
• Car stereos and older players vary. Many read only MP3 (and sometimes WMA or AAC), so check the manual before copying a FLAC library to a USB stick.

What streaming services use

Streaming services make their own copies of the music, so you never stream an MP3 or a FLAC you uploaded. Spotify's support page lists AAC for its web player, app quality settings up to about 320 kbps, and, for Premium, a lossless option of up to 24-bit/44.1 kHz FLAC.

Which should you choose?

Converting FLAC to MP3: which bitrate?

When you need an MP3 copy, convert from the FLAC and choose the bitrate by use:

• 320 kbps: the highest MP3 allows. Use it for music you care about and want as close to the FLAC as possible.
• 256 kbps: a good balance for music. Most listeners find it very hard to tell from 320.
• 192 kbps: fine for everyday listening, playlists and background music.
• 128 kbps: best kept for speech, such as podcasts and audiobooks.

Some encoders also offer variable bitrate (VBR), which spends more data on busy passages and less on quiet ones. LAME's highest-quality VBR setting, V0, is a popular choice for music archives made with desktop tools. Our VBR vs CBR guide explains the trade-off.

Two rules matter more than the exact number. First, always make the MP3 from the FLAC, never from another MP3, because each lossy encode removes more. Second, keep the FLAC. It is the only copy you can make any future format from.

Our FLAC to MP3 converter offers 128, 192, 256 and 320 kbps and starts at 320. It runs in your browser with FFmpeg, so your files are never uploaded. Free users get 5 conversions per month. The output is limited to the first 10 seconds as a preview, with a 20MB input file size limit. Upgrade to Pro for unlimited, full-length conversions.

Converting MP3 to FLAC

You can turn an MP3 into a FLAC with our MP3 to FLAC converter, but it does not bring back anything the MP3 removed. The FLAC will sound exactly like the MP3 and take up more space. Do it only when an app or device insists on FLAC.

The bottom line

FLAC is the better format for keeping music: it is exact, it takes half to two-thirds the space of WAV, and it plays on most modern devices. MP3 is the better format for carrying music: it is two to three times smaller at its best setting and plays almost everywhere. Keep a FLAC master, make MP3 copies at 256 or 320 kbps where you need them, and if you are unsure whether the difference matters to you, run a blind test with your own headphones.