Video Compressor

How to compress a video

1. 1

   Choose a video

   Pick or drop one MP4, MOV, WebM, MKV or MPEG-TS file. You see its size, length, dimensions and streams at once.

2. 2

   Pick quality and size

   Choose Higher quality, Balanced or Smaller file, and a maximum size of Original, 1080p, 720p or 480p. The exact settings are shown before you start.

3. 3

   Compress and compare

   Press Compress Video, keep the tab open, then play the result and compare its size with the original before you download.

What to know

• What the presets really do. Each preset sets an average video bitrate from the picture size and frame rate (about 0.14, 0.09 and 0.05 bits per pixel per frame for Higher quality, Balanced and Smaller file), never more than a share of the original’s own bitrate. Some files state a wrong bitrate in their header, so the size and length of the file are used to check it. The page shows the number it will use. You can also type your own bitrate under the settings.
• No promised size. The tool does not target a file size or promise a percentage saving. It measures the result and shows the real reduction. A higher setting cannot bring back detail the original no longer has.
• When the result is not smaller. A video that is already small can come out larger. The tool then says so, offers your original as the main download and the new version as an option, and does not try again by itself.
• Shape, orientation and frame rate. The picture is only ever made smaller, never enlarged, and keeps its aspect ratio; portrait videos use the same limits turned around. Both sides are rounded down to even numbers, which the encoder needs and changes the shape by well under 1%. The frame rate is not changed, and rotation stored in the file is kept.
• Audio. Audio is kept exactly as it is when the output format can hold it (for example AAC in MP4, Opus in WebM). Otherwise it is re-encoded to AAC, or to Opus where your browser cannot encode AAC. The page says which before you start.
• Formats. Output is MP4 (H.264), WebM (VP9) or WebM (AV1). An output is offered only if your browser can really encode it; desktop Chrome, Edge and Firefox usually can, other browsers may offer less. AV1 gives the smallest files but is much slower to make and plays on fewer devices. MKV and MPEG-TS videos are read and saved as MP4 or WebM.

Supported files

The tools open one MP4, MOV, WebM, MKV or MPEG-TS file at a time. Tested: H.264 video with AAC audio in MP4, MOV, MKV and MPEG-TS, VP9 video with Opus audio in WebM, and HEVC in MP4 (which can be muted and fast-cut anywhere, but only re-encoded where your browser can decode it). MPEG-TS means plain 188-byte .ts files; 192-byte camcorder and Blu-ray streams (.m2ts, AVCHD .mts) are not opened because their audio cannot be read reliably, and a fast cut is not offered for MPEG-TS. Other codecs inside these containers are tried, but whether they work depends on your browser; the tool says so in plain words when it cannot handle a file, and tells a damaged file apart from an unsupported one.

Only the main video track and its main audio track are used. Other tracks, subtitles, chapters and descriptive tags (title, location, creation tool) are not kept. The picture’s rotation and shape are kept, and the frame rate is never changed. Transparency is not kept when a video is re-encoded.

Limits

largest video file

1 GB

longest video

60 minutes

largest picture re-encoded

4K

largest result

500 MB

The video is read from your disk in small pieces, but the finished file is built in memory and then copied once for download, and decoded frames take memory while a run is going, so long or high-resolution videos can fail on phones and small computers. Speed depends entirely on your device and browser, and a run can take longer than the video itself. Cancel stops the work at once and keeps nothing.

Frequently asked questions