How to Compress an Audio File (WAV, FLAC, MP3) Without Ruining the Sound

Why Are Audio Files So Heavy?

An uncompressed recording (WAV) stores the sound exactly: at CD quality, that's about 10 MB per minute. A one-hour interview recorded in WAV weighs around 600 MB — impossible to send by email, heavy for a messaging app, slow to upload to a website.

FLAC compresses without loss and roughly halves that size. MP3, AAC and OGG go much further by removing what the ear barely perceives: a minute of music at 192 kbps weighs about 1.4 MB.

The Key Setting: the Bitrate

The bitrate, in kilobits per second (kbps), determines the quality and the weight of a compressed audio file. Weight in MB ≈ bitrate × duration in seconds ÷ 8,000.

Bitrate	Weight per minute	Quality	Use
64 kbps	~0.5 MB	Correct for voice, poor for music	Voice memos, long recordings
128 kbps	~1 MB	Very good for voice	Podcasts, interviews, courses
192 kbps	~1.4 MB	Excellent for music	Music, mixes
320 kbps	~2.4 MB	Near-CD	Archiving, demanding listeners

Compress an Audio File in 3 Steps

The audio compressor uses FFmpeg compiled to WebAssembly: the compression runs in your browser and your recordings are never uploaded — important for interviews, private meetings or unreleased music.

1. Import your file — MP3, WAV, OGG, AAC, FLAC and most common formats.
2. Choose the output format (MP3 or OGG) and the bitrate.
3. Download the compressed file.

FFmpeg (about 30 MB) is downloaded on first use and then cached: the next compressions start immediately.

How Much Will I Save?

• WAV or FLAC to MP3: typically 80–90% lighter. A 600 MB interview becomes about 58 MB at 128 kbps.
• MP3 to a lower bitrate: usually 30–60% saved (320 → 128 kbps divides the weight by 2.5).
• MP3 to a higher bitrate: useless — you can't recover quality that has been removed. If a setting wouldn't make the file lighter, the tool keeps the original.

MP3 or OGG?

	MP3	OGG (Vorbis)
Compatibility	Universal: every device, every app	Browsers, Android, VLC — less on Apple
Quality at equal bitrate	Very good	Slightly better at low bitrates
Best for	Sharing with anyone	Websites, games, personal use

When in doubt, choose MP3: it plays everywhere.

Practical Cases

Sending a Recording by Email

Email attachments are limited to 20–25 MB. At 128 kbps, that's about 25 minutes of audio. Longer? Lower to 64–96 kbps for voice, or share a link. Check where your file fits with the file limits checker.

Publishing a Podcast

Most hosts recommend MP3 at 128 kbps (mono or stereo). A one-hour episode then weighs about 58 MB.

Keeping a Music Archive

Keep the originals in FLAC (lossless), and create MP3s at 192–320 kbps for your phone.

Conclusion

Compressing an audio file is all about the bitrate: 128 kbps for voice, 192 kbps for music, 320 kbps when quality comes first. Converting a WAV to MP3 divides its weight by 10 with no audible difference for most listeners — in your browser, without uploading anything.