# Compress to Size — Compress video to an exact file size on Mac

Hit a file-size limit for email, Discord or WhatsApp. Pick the size, not the quality. Part of OneMacTools, 151 private tools in one native Mac app (macOS 26 or later); category: Video. Runs on your Mac; nothing is uploaded.

Choose 8 MB for Discord, 16 MB for WhatsApp, 25 MB for email or any size you like. Two-pass encoding fits the video under the limit and lowers the resolution only when that will look better than starving the bitrate. In our tests an 814 MB, 20-second 1080p clip came out at 4.8 MB for a 5 MB limit.

Page: https://www.onemactools.com/tools/compress-video-to-size · Download: https://www.onemactools.com/download · Pricing: https://www.onemactools.com/pricing

## How to use it
1. **Install FFmpeg once.** If FFmpeg isn't installed yet, OneMacTools offers to install it through Homebrew with one click.
2. **Drop your videos.** Drag in the clips that need to fit a limit. Or right-click them in Finder and choose Quick Actions › OMT: Compress Video to 25 MB.
3. **Choose the target size.** Pick 8 MB for Discord, 16 MB for WhatsApp, 25 MB for email, or choose Custom and type any size in MB.
4. **Click Compress.** Each video goes through two encoding passes: the first measures it, the second spends the size budget where it matters.
5. **Send it.** The results, with the size in the name (for example “25MB”), are saved in a new dated folder in Downloads › OneMacTools. Check them with the Preview (eye) button or Show in Finder. Your originals stay as they were.

## Options
- **Target size:** 8 MB — Discord, 10 MB, 16 MB — WhatsApp, 25 MB — Email (the default), 50 MB, 100 MB or Custom. The video is fitted under this size.
- **Size in MB:** Shown when Target size is Custom. Type any size of 1 MB or more, such as 20.

## Tips
- Trim the video first if you can. The same size budget spread over fewer seconds gives a much sharper result.
- If a long video can't fit, the tool tells you rather than making something unwatchable. Pick a larger size or cut it shorter.
- Leave a little headroom. Email services add overhead to attachments, so aim a notch below a hard limit when you're close.
- For very small targets the resolution is lowered to 1080p, 720p or 480p, because fewer, cleaner pixels look better than a starved full-size picture.
- An MP4 that's already under the limit is copied as it is, so it never gets worse for no reason.

## Questions
**How do I get a video under 25 MB for email or 16 MB for WhatsApp?**
Choose the target, or type any size in MB, and click Compress. Two-pass encoding fits the video under the limit.

**How do I make a video small enough for Discord?**
Choose 8 MB — Discord, or 10 MB if your server allows it, and click Compress. Short clips look best; for longer ones, trim to the important part first.

**Will the video look bad?**
It lowers the resolution only when that looks better than squeezing the quality, so you get the sharpest video that fits.

**Why does it say my video is too long to fit?**
Below a certain bitrate there isn't enough data left for a watchable picture, so the tool stops rather than produce a mess. Pick a larger target size or trim the video first.

**What's the difference between this and Compress Video?**
Compress Video lets you pick a quality and the size follows. Compress to Size lets you pick the size and works out the best quality that fits.

**Can I type my own size?**
Yes. Choose Custom and enter any size of 1 MB or more in the Size in MB box.