Make songs, voice notes and recordings smaller by choosing a lower bitrate, right in your browser.
Need to compress an audio file? This tool makes songs, voice notes, lectures and meeting recordings smaller by saving them again at a lower bitrate. It is a quick way to reduce MP3 size for WhatsApp, an email attachment or an upload form with a 10, 14 or 16 MB limit, and it shrinks big WAV and M4A recordings too. You compress audio online, in your own browser: nothing is uploaded, nothing is installed and there is no account. You pick one of four quality levels, the tool re-encodes the sound, and the result shows the size before and after and how many percent smaller the file has become.
The tool decodes your file into plain audio samples with the media engine built into your browser and then encodes those samples again at the bitrate you picked: 32, 64, 96 or 128 kilobits per second. The bitrate decides how much data is stored for each second of sound, so the new size depends only on length and bitrate: size in kilobytes = kbps x seconds / 8. Any video picture in the file is dropped. The sample rate and number of channels of the original are kept.
A real example from our own test on 24 October 2026 (Chrome, desktop): an 8-second WAV recording of 689 KB, compressed to MP3 at 64 kbps, became 63 KB. That is 91% smaller. The formula gives 64 x 8 / 8 = 64 KB, so the measured file matches. WAV is uncompressed, which is why it shrinks so much; an MP3 that already uses a low bitrate shrinks far less.
Drop or choose an MP3, M4A, WAV, OGG, OPUS, AAC or FLAC file. The page shows its name and size.
Choose 32, 64, 96 or 128 kbps. 96 kbps is the default. Lower numbers make smaller files.
MP3 is the default. Open More options to save as M4A, OGG or AAC instead.
Press Start. The result shows the size before and after and how many percent smaller it is. Then press Download.
32, 64, 96 or 128 kbps. Each level gives a predictable size per minute, so you can plan for a limit.
MP3 plays everywhere. M4A and AAC suit Apple devices; OGG uses Opus. Formats your browser cannot create are hidden.
After compressing, you see the size before and after and the percent saved. If it is not smaller, the page says so.
Compression happens on your own device. No sign-up, no watermark and no daily limit.
| Quality | MB per minute | Minutes in 10 MB | Minutes in 14 MB | Minutes in 16 MB | Good for |
|---|---|---|---|---|---|
| 32 kbps | 0.24 | 41 | 58 | 66 | Long lectures, meetings, voice notes |
| 64 kbps | 0.48 | 20 | 29 | 33 | Podcasts, interviews, clear speech |
| 96 kbps (default) | 0.72 | 13 | 19 | 22 | Mixed speech and music, casual listening |
| 128 kbps | 0.96 | 10 | 14 | 16 | Music where you want more detail |
Computed from the settings the tool uses (kbps x seconds / 8, with 1 MB = 1,000,000 bytes, rounded down to whole minutes). Real files can differ by a few percent because of file headers, so leave a little room under a strict limit.
There is no box to type a target size, but the table makes it easy to choose. Find the length of your recording and pick the highest quality whose “minutes” number is bigger than your length.
Examples: a 50-minute lecture fits under 14 MB at 32 kbps (about 12 MB). A 25-minute interview fits under 16 MB at 64 kbps (about 12 MB). A 12-minute music mix fits under 14 MB at 96 kbps (about 8.6 MB) or 128 kbps (about 11.5 MB). If a recording is too long for even 32 kbps, cut it into parts with the MP3 cutter and compress each part.
Voice notes, class recordings and call recordings are speech, and speech stays clear at low bitrates. Pick 32 or 64 kbps and keep MP3, or choose M4A under More options; at these low bitrates M4A (AAC) usually sounds a little clearer than MP3. A smaller file sends faster on mobile data and uses less of the other person’s storage. WhatsApp and other chat apps have their own file size rules, which can change, so check the app if a file is refused. To convert WhatsApp’s own OGG or OPUS voice notes to MP3, use OGG to MP3.
Many email services cap attachments; Gmail, for example, allows up to 25 MB for personal accounts. At 64 kbps that is about 52 minutes of audio; at 32 kbps over 100 minutes. For anything longer, a cloud link is usually better than an attachment.
How much smaller an MP3 gets depends on its current bitrate. The saving is simply the drop in bitrate:
Not by re-encoding. An MP3 is already compressed, and making it smaller always removes some detail. Each new encode also adds a little loss of its own. For music, 96 or 128 kbps keeps the loss small. The only way to save space with no loss at all is to remove parts you do not need, such as silence before a talk starts.
WAV files are uncompressed, so they shrink the most: a stereo WAV at 44.1 kHz uses about 10.6 MB per minute, and the same minute at 96 kbps is 0.72 MB, more than 90% smaller. Phone voice recorders often save M4A; those are already compressed, often at 64 to 128 kbps, so pick a level below the original. You can keep the result as M4A by choosing it under More options. For a straight WAV to MP3 conversion at higher quality (128 to 320 kbps), use WAV to MP3 or M4A to MP3.
The page works in up-to-date Chrome, Edge, Safari and Firefox. On Android, open it in Chrome and choose the recording from Recordings, Music or Downloads. On iPhone, open it in Safari and choose a file saved in the Files app. On a computer, drag the file onto the box. Long recordings are processed faster on a laptop than on a phone, and files over about 1.5 GB may fail on phones because the work happens in the device’s memory.
The size is very predictable because each level is a fixed bitrate. Our 8-second test file came within about 2% of the formula (63 KB measured, 64 KB computed). Expect real files to be within a few percent; very short files can be a bit further off because the file header is a larger part of the total.
Many audio compressors online are upload services: the file goes to a server, is processed and comes back. VidHaul compresses audio on your own device. The page reads your file with the browser’s media engine (WebCodecs), re-encodes it there and hands you the result. Private calls, meetings, interviews and voice notes never leave your computer or phone, and big WAV files do not need to be uploaded first.
The levels are honest fixed bitrates, not vague “low, medium, high” labels, so you can predict the size before you start and check it afterwards. The result always shows the before and after size and the percent saved, and it tells you when a file did not get smaller instead of handing you a bigger one silently.
For every file the page shows the size before and after and the percent smaller, and Copy summary copies those details. The example on this page (689 KB WAV to 63 KB MP3, 91% smaller) is from our own browser test on 24 October 2026. The tables and chart are computed from the bitrates the tool uses. We do not measure sound quality with a score, we do not see your files, and we do not keep statistics about what you compress, because nothing is uploaded.
| VidHaul audio compressor | Typical upload-based audio compressors | |
|---|---|---|
| Upload needed | No, compressed on your device | Usually yes |
| File size limit | None set by us; limited by your device memory | Often a fixed limit, lower on free plans |
| Watermark or added sound | None | Usually none |
| Sign-up | Not needed | Often optional, sometimes needed for large files |
| Works offline after loading | Compression runs locally once the tool has loaded | No, needs a connection for upload and download |
| Privacy | Recordings never leave your device | Files are usually kept on a server for a while |
Only compress recordings you own or have permission to use.
Choose the audio file on this page, pick a quality such as 64 or 96 kbps and press Start. When it finishes, click Download to save the smaller file.
Choose the MP3 and pick a lower quality than the original, for example 96 or 64 kbps instead of 320 kbps. The new MP3 is smaller, with some loss of fine detail.
Divide the limit by the size per minute: at 32 kbps one minute is about 0.24 MB, at 64 kbps 0.48 MB, at 96 kbps 0.72 MB and at 128 kbps 0.96 MB. For 16 MB that is about 66, 33, 22 or 16 minutes; pick the highest quality that fits your length.
For voice recordings pick 32 or 64 kbps and M4A or MP3. Speech stays clear and the file becomes much smaller and faster to send on mobile data.
With an MP3 you cannot. Making it smaller means a lower bitrate, which removes some detail. At 96 or 128 kbps the loss is small for most listening; the safest saving with no loss is to cut away parts you do not need.
Open this page in Chrome on your Android phone, choose the recording from your files, pick a quality and press Start. The smaller file is saved to your Downloads folder.
If the original already has a low bitrate, for example a 64 kbps voice note, compressing it at 96 or 128 kbps will not save space. Pick a level below the original.
No. The audio compressor runs in your browser, so your recordings never leave your device.