Audio & video
How to Compress a Video for Email or Discord
Hit a file size limit exactly by choosing the right bitrate and resolution. The math behind it, current limits, and how to compress in your browser without uploading.
Updated · 3 min read
A 40-second phone video can easily be 80 MB. Email providers typically cap attachments at 20–25 MB (Gmail allows 25 MB), and Discord's limit for free accounts has been much lower, recently 10 MB. Limits change, so check the current number for your service. Here's how to hit any limit reliably.
The formula behind file size
Video file size is almost entirely determined by bitrate (how many bits per second) multiplied by duration:
size (megabits) = bitrate (Mbit/s) × seconds
Working backwards for a 10 MB limit and a 60-second clip:
- 10 MB × 8 = 80 megabits
- 80 ÷ 60 s ≈ 1.33 Mbit/s total
- minus about 0.1 Mbit/s for audio → about 1.2 Mbit/s for video
That's enough for decent 720p. The same clip squeezed into 10 MB at 1080p would look blocky, because the bits are spread over twice as many pixels.
Step 1: Trim first
Every second you cut saves the same amount of space as a second of compression, without any quality loss. Use the video trimmer to keep only the part that matters. Going from 60 to 30 seconds doubles the bitrate you can afford.
Step 2: Compress to a target size
- Open the video compressor and drop the video. It's processed on your device, so there's no upload time for large files.
- Set Control by to Target size and enter a value slightly under the limit, for example 9.5 MB for a 10 MB limit.
- Choose a maximum resolution. 720p is a good default for chat and email; 480p for very long clips.
- Optionally cap the frame rate at 30 fps. Phones often record at 60 fps, which costs bitrate you don't need for most clips.
- Keep audio unless it's not needed; removing it saves a little space.
- Compress and check the result's size and quality before sending.
For the widest compatibility, set the video codec to H.264: it plays everywhere, including older phones and email clients that preview video. HEVC, VP9 and AV1 are smaller at the same quality, but not every recipient can play them.
Choosing resolution by duration
A rough guide for a 10 MB target:
| Clip length | Suggested max resolution |
|---|---|
| Up to 20 s | 1080p |
| 20–60 s | 720p |
| 1–3 min | 480p |
| Longer | Consider a link instead of an attachment |
For a 25 MB limit, you can roughly go one step up.
Other ways to fit the limit
- Reduce the resolution separately with the video resizer if you need a specific size.
- Make a GIF with the video to GIF converter for short, silent loops, but note that GIFs are often larger than an MP4 of the same clip.
- Share a link via cloud storage for long videos. Compression can only go so far before quality suffers.
Why "quality" settings can overshoot
Quality-based settings (like "medium") keep the look consistent but let the size vary with the content. A calm talking-head video comes out small, while shaky footage with lots of motion comes out large. When there's a hard limit, target size mode is the reliable choice.
Frequently asked questions
Why is my compressed file slightly over the target? Containers add a little overhead, and encoders don't hit a bitrate exactly on very short clips. That's why a 5–10% margin below the limit is sensible.
Does compressing again make it worse? Yes. Every lossy compression pass loses detail. Always compress from the original recording, not from an already compressed copy.