WAV vs MP3: when to use which and how to convert

You record a 3-minute voice memo. The WAV file is 30 MB. The MP3 version of the same recording is 3 MB. They sound identical through laptop speakers.

That 10x size difference is the entire WAV vs. MP3 debate in a nutshell.

The difference

WAV stores audio as raw, uncompressed waveform data. Every sample is preserved exactly as recorded. A 3-minute stereo WAV at CD quality (44.1 kHz, 16-bit) is about 30 MB. No data is removed, so the file is as close to the original recording as digital audio gets.

MP3 uses psychoacoustic compression to remove sounds that human ears can’t easily perceive. Frequencies masked by louder sounds, ultra-high frequencies above typical hearing range, and other inaudible details get stripped out. The result is a file that’s 5-10x smaller and sounds the same to most listeners in most situations.

When to use WAV

Recording and editing: Always record in WAV (or another lossless format like FLAC). You want the full audio data before making edits, because every MP3 encode removes a little more information.
Music production: DAWs work with uncompressed audio internally. Export as WAV for mastering, stems, or handoff to other producers.
Archival: If you need a perfect copy of the original audio, WAV is the safe choice. You can always compress to MP3 later; you can’t go back.
Professional voiceover delivery: Clients and studios often require WAV files for broadcast or integration into video projects.

When to use MP3

Sharing: Sending audio via email, Slack, or messaging apps. A 3 MB MP3 attaches and downloads instantly. A 30 MB WAV clogs someone’s inbox.
Web and podcasting: Podcast hosting platforms expect MP3. Web audio players use MP3 or AAC. WAV files would make pages unbearably slow.
Music distribution: Streaming services accept various formats, but listeners downloading for offline use get MP3 or AAC.
Background music and sound effects: If it’s ambient or low-priority audio, the compression artifacts are completely inaudible.

How to convert

WAV to MP3:

Open the WAV to MP3 converter
Drop your .wav file
Download the .mp3

MP3 to WAV:

Open the MP3 to WAV converter
Drop your .mp3 file
Download the .wav

A note on MP3-to-WAV: this increases file size but doesn’t recover lost audio data. The MP3 compression already removed information permanently. Converting to WAV just wraps the existing audio in an uncompressed container. It’s useful when software requires WAV input, but it won’t improve sound quality.

What about FLAC?

FLAC is lossless compression for audio. It reduces file size by about 50-60% compared to WAV without removing any audio data. Think of it as ZIP for audio. The tradeoff: not every device and platform supports it. Use FLAC for archiving or when sharing with people who have compatible players. Use MP3 when you need universal compatibility and small files.

Privacy

Conversion runs in your browser using FFmpeg compiled to WebAssembly. Your audio file never leaves your device. No upload, no server, no account.

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How to reduce image file size (similar compression tradeoffs for images)