Compress audio — reduce file size online, free
Pick a compression level and get a smaller file back in seconds. No install, no account required.
Shrink a file's size for email, upload limits, or storage. Supports MP3, WAV, OGG, M4A, FLAC — 15MB max.
Free to try · No signup required · Commercial use allowed · How we test · About VoxCraft
Compress an audio file online for free with VoxCraft. Upload an MP3, WAV, OGG, M4A or FLAC file, pick a compression level, and get a smaller file back — useful when an email attachment limit, an upload cap, or plain storage space is the problem, not the audio quality itself.
Compression re-encodes the file at a lower bitrate. That always trades some quality for size — the question is how much you can afford to lose for what you're using the file for. A voice memo you're sharing in a chat can usually take the maximum setting without anyone noticing; a music track you care about should stay on the lighter end.
Every input format gets converted to MP3, since that's the practical standard for small file size. If you're starting from an already-compressed MP3, compressing again re-encodes on top of the existing loss — expect more noticeable quality loss than compressing a WAV or FLAC source the first time.
How it works
- Upload your audio file (WAV, MP3, M4A, OGG or FLAC, 15MB max).
- Choose a compression level — Light, Medium, or Maximum.
- Tap Compress and wait a few seconds.
- Check the size before/after shown, then download the result.
Who uses this
Email attachments
Shrink a recording below an inbox's attachment size limit without needing a file-sharing link.
Upload limits
Get a file under a form's or platform's upload cap when the original is too large.
Storage cleanup
Reduce the size of old recordings you want to keep but don't need at full quality.
Faster sharing
Send a smaller file over a slow connection or a messaging app that compresses large attachments poorly anyway.
Tips for better results
- Light (128 kbps) is usually safe for anything you'd still want to sound good — voiceovers, music you care about.
- Maximum (64 kbps) is fine for voice memos and reference recordings where clarity matters more than fidelity.
- Compressing an already-compressed MP3 stacks quality loss — start from the original source file when you still have it.
- Need the opposite — turn a compressed file into an uncompressed WAV? Use Decompress instead.
Frequently asked questions
Will this reduce sound quality?
Yes, to some degree — that's the tradeoff for a smaller file. Light loses the least; Maximum shrinks the most but is the most audible.
What output format do I get?
MP3, regardless of what format you uploaded — it's the practical standard for a small file size.
Is compressing free?
Yes within free-tier limits, no account required to start.
How much smaller will my file get?
Depends on the original bitrate and the level you pick — the result screen shows the exact before/after size and percentage saved for your specific file.
Can I compress a file that's already MP3?
Yes, though re-encoding an already-lossy file loses more noticeably than compressing a WAV or FLAC source the first time.
Is there a file size limit to upload?
Yes, 15MB max per file.