Two ways to make a video smaller
The compressor works in one of two modes, and the right one depends on why you need a smaller file.
- Quality. You choose how good the picture should look, and the file becomes as small as that allows. High quality is hard to tell apart from the original and keeps the resolution. Balanced gives a clean picture and a much smaller file; anything bigger than 1080p is scaled down to 1080p. Smallest scales to 720p and accepts a softer picture.
- Target size. You choose the size, and the tool works out the quality. This is the mode for upload limits. The bitrate is calculated from the length of each video after the space for sound is set aside. If that bitrate is too low for a sharp picture at the full resolution, the resolution goes down. After compressing, each file is measured. If it came out too big, it is made again, up to three times.
Before anything starts, you see an estimate for each file and for the whole list. After compressing, you see the real result, for example 182 MB to 23 MB (−87%).
What makes a video file big
| Factor | Why it matters | What to change |
|---|---|---|
| Resolution | 4K has four times the pixels of 1080p | Choose 1080p or 720p |
| Frame rate | 60 fps stores twice as many pictures as 30 fps | Cap it at 30, 24 or 15 fps |
| Bitrate | Phones and cameras use a high bitrate so nothing is lost while recording | Any quality level or target size lowers it |
| Codec | Newer codecs store the same picture in less space | H.265 or AV1, where your browser offers them |
| Sound | Usually a small part, but it counts for short size limits | Remove audio if the clip doesn't need it |
For most phone videos, the bitrate is the main reason for the size. A phone records far more data than a picture needs on a small screen, which is why even High quality often saves a lot.
Codec and output format
By default each video keeps its own format: an MOV stays MOV, a WEBM stays WEBM. You can also choose one format for all files, which is handy when a WMV or AVI should become a smaller MP4 in the same step. For MP4, MOV and MKV the safe codec is H.264, which plays on phones, TVs, browsers and editors. H.265 (HEVC) saves about 40% more but doesn't play on some older computers. AV1 makes the smallest files and takes the longest to encode. The tool only lists codecs that your browser can actually encode, and each one comes with a short note on where it plays. Old formats such as AVI, WMV, FLV, 3GP and MPEG are written by a built-in converter engine. It is slower, and the whole file has to fit in memory.
When a smaller file isn't possible
Some limits are physical. An hour-long video can't fit into 10 MB with a usable picture. In that case the tool tells you the smallest size it can reach for that length and suggests removing the audio or shortening the video. You can cut the part you need with Trim Video, or split a long recording into parts that each fit the limit with Split Video.
Files that are already compressed well, such as videos saved from a messenger, may not get any smaller. If the compressed copy would be bigger than the original, you simply get the original back. A file that already fits the target size and keeps its format is left as it is. To shrink an animated GIF, use the GIF compressor. It changes colours, width and frame rate instead of the bitrate.
Private, free and without limits
Your videos are compressed by your own computer or phone, inside the browser. They are never uploaded, so a 2 GB file doesn't need a 2 GB upload first, and personal videos stay personal. The page also works offline once it has loaded. There is no watermark, no sign-up and no limit on the number of files. If you need a format-specific page, the MP4 compressor and the other format compressors always save in their own format.