MP3 vs WAV vs FLAC: Differences and Which to Use

Three formats, three approaches

WAV is uncompressed audio: exactly what the microphone or studio software captured. It gives maximum quality but takes up a lot of space. FLAC compresses audio without loss, somewhat like a ZIP file: you get identical sound back, in a file much smaller than WAV. MP3 uses lossy compression, meaning some audio information is discarded permanently.

MP3 discards what the human ear tends not to notice, so at a good bitrate most listeners struggle to hear the difference, especially on ordinary headphones.

How much space files take

CD-quality audio (44.1 kHz, 16-bit, stereo) as WAV takes roughly 10 MB per minute, so a 4-minute song is about 40 MB. FLAC typically cuts that by around half, though the result depends on the music, so that 40 MB song may become 20 to 25 MB.

For MP3, the bitrate decides the size. Roughly: 128 kbps is about 1 MB per minute, 192 kbps about 1.4 MB, 256 kbps about 1.9 MB and 320 kbps about 2.4 MB per minute. These are approximations, since variable bitrate files differ.

Which MP3 bitrate to choose

• 128 kbps: fine for speech, podcasts and voice recordings. In music, the high frequencies may start to sound thin.
• 192 kbps: a good compromise for everyday listening.
• 256 kbps: good quality that most people cannot tell from the original.
• 320 kbps: the top MP3 level. Larger files, but a safe choice if you want to be well above the quality threshold.

Comparison table

When to use which

MP3 suits your phone, car, running playlists and sharing, because it is small and works everywhere. Choose WAV for music production, audio editing or sending files to a studio, since working without loss is simpler. FLAC suits a personal collection when you want CD quality without spending as much space as WAV.

AAC, often stored in M4A files, deserves a mention too. At the same bitrate AAC usually sounds slightly better than MP3, and it is the standard in Apple's ecosystem. For universal compatibility, though, MP3 is still the first choice.

Why MP3 to FLAC does not improve quality

This is one of the most common mistakes. If you already have a song as an MP3, the lost information does not come back, no matter what you convert it to. An MP3 turned into FLAC or WAV will look like a high-quality file, but it will sound exactly like the MP3, just several times bigger.

True FLAC quality only comes from an original source: a CD, a lossless purchase or a studio recording. Converting is worthwhile for compatibility (say, a program that accepts only WAV), but not for quality.

Conversion tips

Convert in the direction of better to worse quality (WAV or FLAC to MP3), and always keep the original. The reverse gains nothing, and re-encoding an MP3 to another MP3 bitrate only damages the sound further.

Our audio converters run in your browser, so your files stay on your computer.

Decision checklist and real examples

Imagine a collection of 200 songs. As 320 kbps MP3 it takes roughly 2.4 MB x 3.5 min x 200, which is nearly 1.7 GB. As WAV the same collection would be about 7 GB, and as FLAC roughly 3.5 to 4.5 GB. These are approximate figures, but they show why MP3 or AAC is usually chosen for a phone, while a home server or computer can afford FLAC.

Another common case: you have a WAV recording from a voice recorder or studio and want to email it. Convert it to MP3 at 192 to 256 kbps and the file shrinks roughly 5 to 7 times, while quality is still plenty for a conversation or a demo.

• Listening on a phone or in a car: MP3 at 192 to 320 kbps, or AAC.
• Making or editing music: work in WAV, export to MP3 only at the end.
• Archiving CDs or lossless purchases: FLAC.
• Sending a recording to someone or posting it online: MP3 at 128 to 192 kbps.
• Not sure what player will be used: MP3, since almost everything opens it.