MP3 vs FLAC vs OGG: an audio format guide

If you have ever stared at a converter and wondered whether to pick MP3, OGG, FLAC, M4A, or WAV, the honest answer is that the difference matters in some situations and not at all in others. This article walks through what each format is, what it costs you, and where the real-world differences show up.

Lossy vs lossless: the actual difference

Every audio format is one of two types.

Lossy formats compress audio by analyzing what the human ear can and cannot hear, then throwing away the parts you cannot hear. A loud sound buried right next to a softer one tends to mask the softer one, so the codec can discard the softer one with no audible loss. Multiply this trick across thousands of small decisions per second and you end up with a file that is 6 to 10 times smaller than the original.

Examples: MP3, AAC (the codec inside M4A), OGG Vorbis, Opus.

Lossless formats compress audio without throwing anything away. The compression is more like ZIP: it finds patterns and stores them efficiently, so when you decompress you get back exactly the original bytes. Files are about half the size of uncompressed WAV, but still 3 to 5 times bigger than a high-quality MP3.

Examples: FLAC, ALAC (Apple's lossless format), WAV (technically uncompressed, but functionally lossless).

The five formats you will actually see

MP3

The grandparent. Released in 1993, became the format of the iPod era, and is still the most widely-supported audio format on the planet. Every device made in the last 25 years can play an MP3.

At 192 kbps or 256 kbps, MP3 is transparent for most listeners on most equipment — meaning you cannot tell it apart from the original in a blind test. At 128 kbps and below, artifacts start to show up, especially on cymbals and other high-frequency content.

Use MP3 when: compatibility matters more than anything else. You are sending a podcast to a stranger, uploading to a service that accepts a narrow set of formats, or burning CDs (still happens).

AAC (M4A)

The successor to MP3, developed by the same group. AAC is more efficient: at the same bitrate, it sounds noticeably better than MP3, especially below 128 kbps. M4A is the file extension for AAC audio in an MP4 container. It is the default for iTunes, Apple Music downloads, YouTube audio, and most podcast apps.

Use M4A/AAC when: you want the best lossy quality per byte and your target devices are modern. Almost universal in 2026.

OGG Vorbis (and Opus)

OGG is an open-source container, usually holding Vorbis or Opus audio. Vorbis is roughly comparable to AAC at common bitrates. Opus is much newer and is the best lossy audio codec available right now — at 96 kbps, Opus sounds better than MP3 at 192 kbps. It is what Discord, WhatsApp voice notes, and most modern streaming uses under the hood.

Use OGG when: you want open formats, you are working with web audio, or you are sending voice / podcast content where Opus's voice mode shines.

FLAC

The most popular lossless format. Open-source, well-supported on Linux, Android, and most modern audio players. Apple devices have grown to support it over the past few years too. A FLAC file is bit-perfect — convert WAV to FLAC and back, and you get the exact original bytes.

Use FLAC when: you are archiving music, ripping CDs, mastering, or doing anything where you might need to re-encode later. Compression to a lossy format from a lossless source is fine; compression from one lossy format to another (MP3 to AAC, say) stacks artifacts.

WAV

Uncompressed PCM audio in a Microsoft container. Huge files (about 10 MB per minute of CD-quality stereo) but the simplest format possible. Every audio tool ever made can read or write WAV. It is the lingua franca of audio editing.

Use WAV when: you are working in an audio editor, sending source files to someone who will edit them, or you need maximum compatibility with very old or very simple software.

What bitrate should you use?

For lossy formats, the file size is determined by the bitrate — how many kilobits per second of audio data the file contains. Rough guide:

• 320 kbps MP3 / 256 kbps AAC. Transparent for almost everyone. Larger files. Use when storage is not a concern and you want a "best lossy" version.
• 192 kbps MP3 / 160 kbps AAC. Transparent for most listeners on most equipment. The mainstream sweet spot.
• 128 kbps MP3 / 96 kbps AAC. Fine for podcasts and voice. Audible compromise on music but acceptable for casual listening.
• 64 kbps and below. Voice-only. Music will sound thin and artifact-y.

Opus is more efficient — 64 kbps Opus is roughly as good as 128 kbps MP3, and 96 kbps Opus is genuinely hard to distinguish from lossless for most music.

Common audio conversion situations

"I have a FLAC album, I need MP3 for my old car stereo"

Convert to MP3 at 256 or 320 kbps. The old hardware does not benefit from anything above that, and you keep the broadest compatibility. Keep the FLACs as your master copy.

"My voice memo is too big to email"

Convert WAV or M4A voice to OGG Opus or MP3 at 64 to 96 kbps. Voice compresses extremely well at low bitrates.

"I'm uploading a podcast"

Most podcast hosts accept MP3 at 128 to 192 kbps. AAC is also fine for hosts that accept it. Avoid going lower than 96 kbps mono / 128 kbps stereo for spoken content.

"I want the smallest possible file with decent quality"

Use Opus inside an OGG or WebM container. For music, 96 kbps Opus sounds remarkable. For voice, 32 kbps Opus is usable.

"I'm archiving my CD collection"

FLAC, every time. Lossless, half the size of WAV, future-proof. If you want a portable copy too, encode each FLAC to a 256 kbps AAC or MP3 alongside it.

What about that "Hi-Res Audio" thing?

Some services sell 24-bit, 96 kHz or even 192 kHz "hi-res" audio files. Whether you can actually hear the difference compared to standard 16-bit, 44.1 kHz CD-quality audio is a long-running debate in audio circles. Multiple double-blind tests have found that very few listeners reliably distinguish them, and only on excellent equipment with specific source material.

For practical purposes, CD-quality FLAC is overkill for almost everyone, and "hi-res" formats are overkill for almost everyone who calls CD-quality overkill. Pick the format that fits your storage, devices, and use case.