Shrink video file sizes with adjustable quality, compressed entirely in your browser, files never uploaded.
Your video is compressed locally with FFmpeg running in your browser. Nothing is uploaded; the file never leaves your device. First use downloads the ~31 MB engine once. Files up to 200 MB.
Bitrate is computed from the video's duration.
Loading engine…
Most videos are larger than they need to be because cameras and phones record at high bitrates to preserve every detail for editing. This tool re-encodes your video with H.264 at a controlled quality level, which is the same codec most platforms use anyway. Compression works by spending fewer bits on detail your eyes are unlikely to notice: motion, noise, and complex textures are where the savings come from.
Quality is set with the x264 constant rate factor (CRF). The scale runs in reverse of what you might guess: a lower CRF means better quality and a larger file, while a higher CRF means a smaller file with more visible loss. CRF 23 keeps quality nearly indistinguishable from the source, CRF 28 is a solid everyday balance, and CRF 32 produces the smallest files at a noticeable quality cost. The 720p option rescales the frame height, which saves additional space on 1080p-or-larger sources by throwing away resolution rather than fidelity.
Compression runs locally with FFmpeg compiled to WebAssembly, so your footage is never uploaded. Note that already well-compressed videos (such as clips from messaging apps) may shrink only a little; there is not much redundancy left to remove. Need a different format instead of a smaller file? Use the Video Converter.
Video codecs spend bits describing what each frame looks like. Source files from cameras reserve far more bits than needed for casual sharing. Re-encoding with H.264 at a higher CRF lets the encoder skip fine detail (film grain, noise, subtle textures) that human vision barely registers, which can cut file size dramatically with little visible change.
That depends on the CRF you choose. At CRF 23 the difference is essentially invisible for most footage. CRF 28 is still very watchable and typically shrinks camera files a lot. CRF 32 produces visibly softer output, best for previews or when size is the only priority. You can always re-run the tool with a different setting.
Use it when the video will be watched on a phone, embedded in a chat, or published to social media, and when the source is 1080p or larger. Dropping the resolution to 720p reduces the number of pixels the encoder must encode, which saves space without introducing compression artifacts. Skip it if the video will be edited further or shown full-screen on a large display.
Upload-based compressors send your footage to a server you do not control, wait in a queue, and process it on hardware you cannot inspect. This tool runs FFmpeg inside your browser tab: nothing is transmitted, there is no queue, no file retention policy to trust, and no account required. The trade-off is that it uses your own CPU, so it is slower on weak machines.
Video is re-encoded with H.264 (libx264, ultrafast preset) and audio with AAC at 128 kbps. This combination plays on virtually every device, browser, and editing app. The ultrafast preset prioritizes speed over squeezing out the last few percent of size, a worthwhile trade for a browser tool.