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Compress audio files

FreeNo uploadNo signupWorks offline

Make audio files smaller for email, WhatsApp, Discord or upload forms. Choose a lower bitrate, or enter the maximum size in MB and the tool picks the best quality that fits. Works with MP3, WAV, M4A, video files and more.

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How to use Compress Audio (MP3)

Compress Audio (MP3) – Make MP3 and other audio files smaller, or fit a size limit. Free, no upload.
  1. Choose or drop your audio files.
  2. Pick a bitrate, or switch to “Target size” and enter the maximum MB.
  3. Click Compress.
  4. Check the new size and download.

Supported formats

  • Input: MP3, WAV, M4A, FLAC, OGG, Opus, MP4, MOV, WebM
  • Output: MP3

How much smaller?

A WAV becomes 5–15 times smaller as MP3. An existing 320 kbps MP3 becomes about 60 % smaller at 128 kbps. Speech sounds fine at 64–96 kbps, especially in mono.

Hit a size limit

In Target size mode the tool calculates the highest MP3 bitrate whose file fits the limit, based on the recording’s length. For example, Gmail attachments can be up to 25 MB in total, so enter 24 MB to leave room for the email itself.

How long a recording fits

An MP3’s size depends only on its bitrate and length. This table shows roughly how many minutes fit under common limits:

Approximate; MP3 size is about bitrate × 0.0075 MB per minute.
BitratePer minuteFits in 10 MBFits in 25 MBSounds
128 kbps0.96 MB10 min26 minGood for music
96 kbps0.72 MB13 min34 minGood for speech and casual music
64 kbps0.48 MB20 min52 minClear speech, especially in mono
48 kbps0.36 MB27 min60 min (the tool’s maximum)Smallest usable speech

How to compress audio on a phone

Open this page in Safari (iPhone) or Chrome (Android), tap “Choose files” and pick the recording. Choose a bitrate or a target size, tap Compress and download – the smaller file is saved to Files → Downloads on iPhone or the Downloads folder on Android, ready to attach or upload.

What people compress audio for

Usually to get under a limit:

  • Email attachments, which most providers cap at 20–25 MB.
  • Upload forms for assignments, job applications and auditions that set a maximum size.
  • Chat apps and Discord, whose free plans limit file size.
  • Saving space on a phone or in cloud storage, especially for long voice recordings and lectures.

Limitations

  • Up to 60 minutes and 500 MB per file.
  • Which input formats open depends on your browser: Chrome and Edge read the most formats.
  • Output is MP3.
  • Very long recordings cannot fit very small sizes (MP3 needs at least 32 kbps).

Privacy

Files you choose are read into your browser’s memory and processed on your device; they are not uploaded to a server. Temporary download links are released after use, and the offline cache never stores your documents. More about privacy and limits.

Frequently asked questions

Can I compress audio without losing quality?

From WAV or FLAC, 192–256 kbps MP3 is indistinguishable for nearly everyone. Re-compressing an MP3 to a lower bitrate always removes some detail, so pick the highest bitrate that fits your limit.

Should I choose mono?

For voice recordings, yes – at the same bitrate, mono sounds clearer because all the data goes to one channel. Keep stereo for music.

How do I make an audio file small enough to email?

Switch to “To a target size”, enter 24 MB (for Gmail’s 25 MB limit) and click Compress. The tool picks the best quality that fits.

Why didn’t my file get smaller?

If the original MP3 already has a low bitrate, compressing it at a higher bitrate makes it bigger. Choose a bitrate below the original’s, or use target size mode.

Can I compress several files at once?

Yes. Add all of them; each is compressed with the same settings and you can download them together as a ZIP.

Can I compress the audio of a video?

Yes. Drop the video and you get its soundtrack as a smaller MP3 (the picture is not kept).

Are my files uploaded?

No. The audio is decoded and processed in your browser, so recordings and videos never leave your device.

Is it free?

Yes – free with no signup, no watermark and no daily limit.

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