“Compress it to fit” sounds like a one-click job. We ran our own Video Compressor on two test clips, through every preset and several custom size targets, and measured what actually came out. Presets behave predictably. Size targets do not always: on busy footage the result can land at several times the size you asked for, and the fix is one setting most people skip.
How the compressor works
The Video Compressor plays your video in the browser, redraws each frame at the chosen size and records it again at a target bitrate. Nothing is uploaded. Because it re-records, three things follow: it takes as long as the video lasts, the result is a WebM file even if you add an MP4, and the bitrate you set is a target for the encoder rather than a hard limit. In our tests that last point is what matters.
The presets work out their target from the original file's bitrate:
| Preset | Target bitrate | Resolution |
|---|---|---|
| Balanced | 50% of the original | Capped at 720p |
| Maximum Savings | 30% of the original | Capped at 480p |
| 55% of the original, within a 16 MB limit | Capped at 720p | |
| Discord / Email | 60% of the original, within Discord's 20 MB limit | Kept |
| Custom Target Size | Whatever fits the size you pick | Kept unless you change it |
What we tested
We made two 8-second clips at 1920 × 1080 and 30 frames per second, with an audio track, from our own tool screenshots. The slow clip is a smooth pan over a calculator screen, like a screen recording (6.89 MB, 7.2 Mbps). The fast clip is a quick pan across several detailed screenshots with coloured noise on top, a hard case like detailed handheld footage (8.26 MB, 8.7 Mbps). They are not real camera footage, so use the sizes as a pattern rather than a prediction.
What each preset produced
| Preset | Slow clip | Fast clip | Output size |
|---|---|---|---|
| Original | 6.89 MB | 8.26 MB | 1920 × 1080 |
| Balanced | 2.81 MB (−59%) | 3.53 MB (−57%) | 1280 × 720 |
| Maximum Savings | 1.78 MB (−74%) | 2.19 MB (−73%) | 852 × 480 |
| 2.90 MB (−58%) | 3.86 MB (−53%) | 1280 × 720 | |
| Discord / Email | 3.72 MB (−46%) | 4.60 MB (−44%) | 1920 × 1080 |
The savings come from two things at once: a lower bitrate and, for Balanced, WhatsApp and Maximum Savings, fewer pixels. Discord / Email only lowers the bitrate, so it saves the least. Both a 16 MB and a 20 MB limit are far above these 8-second clips; the limits matter for longer videos, and the next table shows how they translate into bitrates. The tool shows an estimated size before you start, and it was above the real size for every preset (for Balanced, an estimate of 3.5 MB against 2.81 MB for the slow clip), so treat the estimate as a ceiling for presets.
When you ask for an exact size
With Custom Target Size you pick a file size, and the tool works out the bitrate that should produce it. We asked for 2, 1 and 0.5 MB and compared the result with the request:
| Target (1080p kept) | Slow clip result | Fast clip result |
|---|---|---|
| 2 MB | 2.13 MB (1.06×) | 2.50 MB (1.25×) |
| 1 MB | 1.15 MB (1.15×) | 2.01 MB (2.0×) |
| 0.5 MB | 0.60 MB (1.21×) | 1.79 MB (3.6×) |
On simple footage the result was within about 6% to 21% over the request. On the busy clip the encoder could not reach a low target at full size and went well over: asked for 1 MB, it gave 2 MB. For the 1 MB request the estimate shown before starting said 1.0 MB in every case, so it does not warn you. If you must stay under a limit, check the result before you send it.
Working out the bitrate a limit allows
A video's size is its average bitrate multiplied by its length, divided by 8. Turning that around gives the highest average bitrate (video and audio together) that fits a limit:
| Video length | 16 MB limit | 20 MB limit |
|---|---|---|
| 30 seconds | 4,474 kbps | 5,592 kbps |
| 1 minute | 2,237 kbps | 2,796 kbps |
| 3 minutes | 746 kbps | 932 kbps |
| 10 minutes | 224 kbps | 280 kbps |
This is why long videos suffer most: a 10-minute video under 16 MB has under a quarter of a megabit per second to work with, which is very little even at low resolution. Platform limits change, so check the current limit where you are sending the file before you rely on the figures above. If the numbers do not leave enough bitrate, shorten the video first with the Video Trimmer rather than squeezing the whole thing. For Discord specifically, the Discord Video Compressor does this maths for you: it picks the bitrate, resolution and frame rate for the 20 MB free limit (raised from 10 MB in August 2026) and re-checks the final size.
Step by step
- Open the Video Compressor and add your video.
- If you just want it smaller, pick Balanced. If you have a size limit, pick Custom Target Size, set the size slider, and open Show advanced to lower the resolution (480p for small limits).
- Click Compress Video Now and keep the tab open until it finishes: it runs at the speed of playback.
- Compare the original and result in the side-by-side player, and check the size shown.
- If it is still over your limit, lower the resolution, shorten the video, or mute the audio (the advanced options include a mute switch). Our resolution and bitrate guide explains what each setting costs.
The result is a WebM file. Most browsers and many apps play it, but not every app or device accepts it, so open it in the place you will use it before you rely on it. To change the format, use the Video Converter, and to change only the dimensions use the Video Resizer.
What we did not test
We tested Chrome on a desktop with two generated 8-second clips. We did not test real camera footage, long videos, phones, or other browsers, whose recording behaviour can differ. We did not run quality scores, so we cannot say how the results look compared with other compressors; judge that on your own video with the side-by-side player.
