How to compress a video to 20 MB (and actually hit it)
A 20 MB limit does not care how close you got. The upload form rejects 20.4 MB exactly as flatly as it rejects 200 MB, which is why the usual routine — compress, check, compress again — wastes both your time and your picture. The honest fix is to hand the encoder the number itself and let it work backwards.
Where 20 MB limits actually appear
Twenty megabytes is a number chosen by systems, not by people watching video. It shows up on job application portals that ask for a video introduction, in CMS upload fields configured years ago and never revisited, and in email systems whose administrators set a conservative attachment ceiling and moved on. None of these venues care what the video looks like — only that the file fits.
The limit is popular precisely because it is cautious. A 20 MB file survives every hop it is likely to take: the mail relay that adds encoding overhead, the intranet that scans attachments, the form backend with a request-size cap slightly above it. Whoever picked the number was protecting infrastructure, which is why appealing to them is pointless and fitting under it is the whole game.
It is also a genuinely awkward target to hit by hand. Quality-based settings produce whatever size the footage demands, so the same preset that lands a calm clip at 14 MB pushes a busy one to 31 MB. That is not a flaw in the preset — it is what constant quality means — but it makes a hard byte ceiling a different kind of problem, and it needs a different kind of mode.
The arithmetic: what fits inside 20 MB
Twenty megabytes is about 160 megabits, and a video file is nothing more than bits per second multiplied by seconds. Fix the size and the duration, and the bitrate is decided for you. A one-minute clip gets roughly 2.6 Mbps — enough for genuinely solid 1080p. At five minutes the budget drops to around 530 kbps, which buys decent 480p. At ten minutes you are down near 260 kbps, where every choice matters.
This is exactly the calculation Target Size mode runs. When you set 20 MB, the engine reads the file — duration, resolution, frame rate, codec — and works out the combination of video bitrate, output resolution and audio treatment that spends the budget best. A short clip keeps its full resolution because the bitrate can support it; a longer one is stepped down, because sharp 480p beats smeared 1080p at the same byte count every time.
The encode itself runs in two passes: the first surveys the whole video to learn where the difficult scenes are, the second spends the bit budget accordingly. The result lands within about 3% of the target, and never intentionally over it — a 20 MB target comes back as a file in the 19-and-something range that the upload form actually accepts, not a 20.6 MB near miss.
The steps, and what happens at the edges
The flow is short. Open the Video Compressor — it runs in the browser, free, with no signup — and add a file up to 2 GB. Instead of a quality preset, pick the ⭐ Target Size card. The quick chips cover the limits people actually face: 5, 8, 10, 16, 20, 25, 50 and 100 MB. Tap 20 MB, or set any custom value from 5 to 500 MB with the slider or the number input.
The advanced options exist for the cases the automatic choice cannot know about. Keep resolution and keep FPS pin those properties when a submission spec demands them; remove audio hands the entire budget to the picture, which transforms long silent screen recordings; preserve metadata keeps timestamps and location; and the codec selector — Auto, H.264, H.265 or AV1 — trades compatibility against efficiency, with a fast encode versus maximum compression switch on top.
And an impossible ask never fails. Set 20 MB for an hour of 4K and the job still completes — you get the closest file the engine can honestly produce, along with concrete suggestions: raise the target, allow a lower resolution, or drop the audio track. Nothing you upload stays around either way; files are deleted automatically after a few hours.
Step by step
- 01
Open the Video Compressor
Open the free Video Compressor in your browser. There is nothing to install and no account to create.
- 02
Add your video
Drag in the file or pick it from your device — anything up to 2 GB. The engine reads its duration, resolution, frame rate and codec to plan the encode.
- 03
Pick the Target Size card
Instead of a quality preset, select the ⭐ Target Size card. This switches the encoder from aiming at a quality level to aiming at a file size.
- 04
Set the target to 20 MB
Tap the 20 MB quick chip. If your limit is different, pick another chip — 5, 8, 10, 16, 25, 50 or 100 MB — or set any value from 5 to 500 MB with the slider or number input.
- 05
Compress and download
Start the job. The two-pass encode lands within about 3% of 20 MB and never intentionally over it. Download the result — files are deleted automatically after a few hours.
Frequently asked questions
Will the file come out at exactly 20 MB?
Within about 3%, and never intentionally over. The two-pass encode is aimed slightly under the target so the file you download actually clears the limit — expect something in the 19-and-something MB range rather than 20.0 exactly.
What if 20 MB is impossible for my video?
The job never fails. You get the closest file the engine can honestly produce, plus concrete suggestions for closing the gap: raise the target, allow a lower resolution, or remove the audio track and give the whole budget to the picture.
Can I target a size other than 20 MB?
Yes. The quick chips cover 5, 8, 10, 16, 20, 25, 50 and 100 MB, and the slider or number input accepts any custom value from 5 to 500 MB. The same analysis and two-pass encode apply at every target.
Is this free, and what happens to my file?
Completely free, no signup, no watermark, and Target Size mode is not behind any tier. Inputs up to 2 GB are accepted, and both your upload and the compressed result are deleted automatically after a few hours.