Compress a video to a target file size
Type a ceiling in megabytes and the compressor solves the bitrate that fits it, encodes locally, measures what came out and corrects itself if it overshot. No upload, no account, no guessing at a quality slider until something happens to fit.
Drop your video here
or click to browse — MP4, MKV, MOV, WebM, AVI and more
Pick your ceiling
- Compress video to 5 MB The tightest ceiling here. Past about three minutes it stops being possible at all.
- Compress video to 8 MB The classic chat and forum attachment wall. Tight enough that duration decides everything.
- Compress video to 10 MB The default cap on a huge number of upload forms — and 25% more room than 8 MB.
- Compress video to 16 MB The WhatsApp video ceiling — and the one target where the platform re-encodes after you.
- Compress video to 20 MB The default in helpdesks, CMS media libraries and upload widgets. Rarely announced.
- Compress video to 25 MB The Gmail attachment limit — with the base64 overhead that makes 25 MB less than it looks.
- Compress video to 50 MB Roomy enough that 1080p survives on short clips. The first target that stops hurting.
- Compress video to 100 MB Generous enough for real 1080p. Also GitHub's hard per-file push limit.
- Compress video to 200 MB Big enough that the real question is your viewer's patience, not the platform's limit.
- Compress video to 500 MB Discord Nitro's per-file ceiling, and the point where the browser becomes the bottleneck.
Which one do you actually need?
Ten options is a lot for something that is fundamentally one number, so here is the short version. If a platform rejected your file and named a size, use that page and set the target slightly below it. If it rejected your file without naming a size, work downwards: 20 MB clears most upload widgets and helpdesk forms, 10 MB clears nearly all of them, and 5 MB clears the ones written before anybody expected video to be attached to a web form at all.
If nothing has rejected anything and you just want the file smaller, the useful question is where a ceiling stops being about survival. The range splits into three fairly distinct parts.
- 5 to 16 MB — every choice here is a compromise. Duration decides the outcome, resolution is the only lever that really moves, and past a few minutes the honest answer is to trim the clip.
- 20 to 50 MB — the useful middle. A clip of ordinary length survives at a resolution people are happy to watch, and you can stop thinking about the arithmetic.
- 100 to 500 MB — picture quality is no longer what you are trading. What costs you at this end is encoding time, browser memory and the patience of whoever has to download the result.
And at the top of the range there is a question worth asking before you start, which is whether to compress at all. Re-encoding is one-way and a large file is not automatically a problem. The 200 MB page works through when the answer is to leave it alone.
Which size holds which resolution
Duration decides everything. The same 25 MB that carries a crisp 1080p thirty-second clip carries a soft 480p five-minute one, because file size is bitrate multiplied by time and the time is not negotiable. This grid shows the highest resolution each ceiling can realistically hold at four common clip lengths.
| Target | 30 s | 1 min | 5 min | 20 min |
|---|---|---|---|---|
| 5 MB | 720p 1,214 kbps | 480p 575 kbps | Not viable — | Not viable — |
| 8 MB | 1080p 2,019 kbps | 720p 945 kbps | 360p 150 kbps | Not viable — |
| 10 MB | 1080p 2,556 kbps | 720p 1,214 kbps | 360p 204 kbps | Not viable — |
| 16 MB | 1080p 4,166 kbps | 1080p 2,019 kbps | 360p 333 kbps | Not viable — |
| 20 MB | 1080p or original 5,240 kbps | 1080p 2,556 kbps | 480p 440 kbps | Not viable — |
| 25 MB | 1080p or original 6,582 kbps | 1080p 3,227 kbps | 480p 575 kbps | Not viable — |
| 50 MB | 1080p or original 13,293 kbps | 1080p or original 6,582 kbps | 720p 1,214 kbps | 360p 271 kbps |
| 100 MB | 1080p or original 26,715 kbps | 1080p or original 13,293 kbps | 1080p 2,556 kbps | 480p 575 kbps |
| 200 MB | 1080p or original 53,559 kbps | 1080p or original 26,715 kbps | 1080p or original 5,240 kbps | 720p 1,214 kbps |
| 500 MB | 1080p or original 134,089 kbps | 1080p or original 66,980 kbps | 1080p or original 13,293 kbps | 1080p 3,227 kbps |
Conservative figures for general footage. Screen recordings and talking heads hold up a step higher; grain, water and fast motion need a step lower.
How target-size compression works here
A file size limit is an arithmetic problem, not a quality problem. Your ceiling in megabytes converts to a number of bits; divide that by the length of the clip in seconds and you have the bitrate you are allowed to spend. Take the audio track off the top and the remainder is your video budget.
total_kbps = target_MB × 8 × 1024 / duration_seconds
video_kbps = total_kbps × 0.96 − audio_kbpsThe 0.96 is headroom for container and muxing overhead. That still leaves the harder half of the problem: rate control is a prediction, not a guarantee, and on footage the encoder finds difficult the finished file can land above the number it was aiming at.
So the tool checks. After the first encode it measures the actual output, and if it came in over your ceiling it scales the bitrate by exactly how far over it landed and runs again, up to three passes. That closed loop is the difference between a target that is a suggestion and a target that is a limit.
Aim under the limit, not at it
Leave yourself 5–10%. Platforms do not all measure size the same way — some count the encoded message rather than the file, some round, some apply the cap after adding their own metadata — and being two megabytes over a hard limit fails exactly as completely as being two hundred megabytes over. Targeting 23 MB against a 25 MB cap costs you nothing you can see.
The one exception is a platform that re-compresses what you send, which is most social and messaging apps. There, handing over the highest quality that fits is the right move, because whatever you send is the ceiling on what anyone can receive. The WhatsApp page goes through that trade-off.
Related
- Video file size calculator — run the arithmetic for any size, length or bitrate.
- Compress video for Discord — the platform this cluster mostly exists for.
- Compress by format — start from the file you actually have.
- What is video bitrate? — the number all of this is denominated in.
- Shrink a video — the manual route, with the quality slider.