Filery

Compress Video

Shrink a video file to a target size or quality level.

Choose video file or drop it anywhere on this page MP4 · MOV · WEBM · MKV · AVI · WMV · FLV · M4V · 3GP · MPEG · +3 Processed on your device — never uploaded

How to compress video

  1. Drop a video in.
  2. Choose CRF mode for consistent quality or target size mode to hit a specific file limit.
  3. Pick a codec — H.264 plays everywhere, VP9 and AV1 compress better but take longer to encode.

About this tool

Video files accumulate quickly. A few minutes of phone footage at default settings can fill a hundred megabytes, and an hour of screen recording can reach several gigabytes. The practical problems are storage space, upload limits, and email attachment restrictions — and the fix is compression, which makes the file smaller by encoding the content more efficiently.

CRF mode (Constant Rate Factor) is the most reliable approach for most people. You set a quality level and the encoder decides how many bits to spend on each frame. Easy-to-compress scenes (static talking head, plain background) get fewer bits; fast action or complex texture gets more. The resulting file has consistent visual quality even though the bitrate varies. Target size mode is the right choice when you have a hard constraint — an email attachment limit of 25 MB, or a platform upload cap — but it will hit the target at whatever quality that allows, which may be poor for a long clip.

AV1 offers the best compression efficiency of the three codecs and is now supported in all current browsers, but it encodes significantly more slowly than H.264. For a short clip where you want the smallest possible file it is worth the wait. For a long clip you need to process quickly, H.264 is the better choice.

Questions

What CRF value should I use?
For H.264, CRF 23 is the encoder default and produces good quality. CRF 28 is a useful compression target — files are typically 40 to 60 percent smaller than at 23 with differences that are hard to see on standard screens. CRF 18 is near-lossless but only a little smaller than the original. For VP9 and AV1 the same scale applies but the codec produces a smaller file at the same perceived quality level.
How much smaller will my video get?
It depends heavily on how the source was encoded. A phone video recorded at high quality CRF compresses less than a screen recording or a video that was already compressed at a low bitrate. Gains of 50 to 80 percent are common for camera footage; gains on already-compressed material may be only 20 to 30 percent.
Why is processing slow?
Compression is computation-heavy: every frame must be decoded and re-encoded with a different quality target. WebCodecs hardware acceleration helps significantly in Chrome and Edge. ffmpeg.wasm (the fallback for Safari and Firefox) is purely software-based and runs at roughly one-fifth the speed of a native encoder. A five-minute clip at 1080p might take two to five minutes in the browser. If you need to process many hours of footage, a desktop encoder like HandBrake will be faster — we would rather tell you that than pretend otherwise.
Can Filery stabilise shaky video?
No. Video stabilisation requires the vidstab filter, which analyses motion vectors across the whole clip in a first pass and then re-encodes in a second. The vidstab native library is not available in WebAssembly builds of ffmpeg, and even if it were, two full passes over a long clip would take many minutes. We decided not to offer a tool that would make people wait that long for a result they could not preview.