Audio Compressor
Control dynamics with threshold, ratio, attack, release, and makeup gain — entirely in your browser.
Drop a file here or browse
MP3, WAV, FLAC, M4A, OGG — compressed locally, never uploaded
What it does
Audio Compressor makes files smaller so they fit WhatsApp, email, Discord, SMS/MMS, Slack, and web uploads. You pick a platform, a target size, or a custom MP3 bitrate — the tool encodes in your browser and downloads an MP3. Nothing is uploaded to a server.
Bitrate controls the quality–size trade-off: higher bitrates (256–320 kbps) stay close to the original for music; lower bitrates (64–128 kbps) shrink voice notes and long recordings for chat apps. Estimated output size updates as you change the preset.
Platform limits at a glance
WhatsApp works best under about 16 MB for reliable sharing. Email attachments are often capped near 25 MB. Free Discord is about 10 MB. SMS/MMS is roughly 1 MB depending on the carrier. Slack and web embeds are more generous, but smaller files still send and load faster.
Limits change over time and can differ by device or plan, so treat these numbers as practical targets rather than hard guarantees. If a share still fails, drop one bitrate step or trim a few seconds of silence at the ends.
When to use which mode
For a platform auto-picks a sensible bitrate under that app’s limit. Target file size aims for a maximum megabyte budget. Custom bitrate lets you dial quality by ear. Preview the original anytime; Compress & Download exports the MP3.
For music demos and finished tracks, start around 192–256 kbps and only go lower if the destination requires it. For speech, podcasts, and voice notes, 64–128 kbps is usually enough and keeps chat apps happy. Stereo sources stay stereo in the export when the encoder allows it.
How to use it
Load your audio
Drop an MP3, WAV, FLAC, or other supported file. It is decoded locally in the browser.
Choose a mode
Pick For a platform, Target file size, or Custom bitrate depending on where you will send the file.
Check the estimate
The panel shows bitrate and estimated MP3 size, plus how much smaller it is than the source.
Compress & download
Export an MP3 encoded in your browser. Use Download again from the ready bar if you need another copy.
Tip: For music keep 192 kbps or higher when you can; for voice notes 64–96 kbps is usually enough and stays under tight MMS limits.
Questions about Audio Compressor
01How do I compress an audio file for WhatsApp?+
Upload your file, open the For a platform tab, choose WhatsApp, and click Compress & Download. The tool picks a bitrate that keeps the MP3 under WhatsApp’s practical limit so the file sends and previews reliably on mobile networks.
02How small can I compress an MP3?+
You can go down to about 32 kbps. That is fine for voice memos, but music will sound thin. For podcasts try 64–96 kbps; for music 128 kbps is a practical minimum and 192 kbps is a comfortable everyday quality.
03What is the difference between bitrate and file size?+
Bitrate is how many kilobits of audio are stored per second. File size is roughly bitrate × duration. A 3-minute track at 128 kbps is about 2.9 MB; at 320 kbps it is about 7.2 MB. Lower bitrate means a smaller file and more compression artifacts.
04Will compression reduce the audio quality?+
Yes — MP3 is lossy. Voice and podcasts tolerate lower bitrates well. Music starts to lose sparkle below 128–192 kbps. Use Custom bitrate if you want to hear the trade-off before you share the file.
05Is my file uploaded to a server?+
No. Encoding runs entirely in your browser with a local MP3 encoder. The audio never leaves your device, and nothing is sent to our servers for compression.
06What input formats can I compress?+
Any format your browser can decode — MP3, WAV, FLAC, OGG, AAC, M4A, and more. Output is MP3 because it is the most widely supported format for chat apps, email, and the web.
Library
0No tracks yet. Upload a file to add it to your library.