Video Compressor & Resizer
Shrink MP4/WebM videos right in your browser with resolution presets and bitrate control, plus a live estimated file size before you export.
Drag & drop an MP4 or WebM video here, or click to browse
Up to 100MB, with a safer limit on lower-memory devices. Processing stays in your browser.
Video Compressor & Resizer shrinks MP4 and WebM files up to 100MB entirely inside your browser tab — no upload, no waiting on a server queue, and no file ever leaving your device. It works by drawing every frame of your source video onto an HTML5 canvas at your chosen resolution and re-encoding that canvas with the browser's own MediaRecorder API.
You get the three controls that actually move the needle on output size: a resolution preset (Original, 1080p, 720p, or 480p), a bitrate slider, and an optional 'keep audio' toggle — with a live estimated output size and percentage reduction shown before you commit to exporting anything.
How to use the Video Compressor
- 1
Upload your video
Drag an MP4 or WebM file (up to 100MB) onto the drop zone, or click to browse. The video loads locally and its duration and dimensions appear immediately.
- 2
Pick a resolution
Choose Original, 1080p, 720p, or 480p. Picking a lower preset automatically suggests a matching default bitrate, which you can still fine-tune.
- 3
Adjust the bitrate
Drag the bitrate slider between 0.5 and 10 Mbps. Lower values shrink the file further at the cost of visual quality — watch the live size estimate update as you move it.
- 4
Check the live estimate
Before you export anything, the tool shows an approximate output size and percentage reduction based on your current resolution, bitrate, and audio settings.
- 5
Compress and download
Click Compress video. The browser plays the source video once in the background while recording the processed canvas, then hands you a download button with the final file size.
Why convert in your browser instead of uploading to a server?
Zero upload, zero server cost
The entire re-encode — decoding, scaling, and recording — happens with browser-native APIs (Canvas and MediaRecorder). Your video file never touches a network request.
See the size before you commit
The live estimate turns bitrate tuning into a quick feedback loop instead of a guess-export-check-repeat cycle.
Sensible resolution presets
1080p, 720p, and 480p cover the common 'make this smaller for messaging or upload limits' use case without needing to know exact pixel dimensions.
No account, no watermark, no daily limit
Compress as many videos as your browser's memory allows, with nothing added to the output.
Frequently asked questions
Why is my downloaded file a .webm instead of .mp4?+
Browsers record canvas output through the MediaRecorder API, and most desktop Chrome and Firefox builds only support encoding to WebM (VP8/VP9), not MP4, without a much heavier WASM transcoder. Safari can produce MP4 directly. The tool shows you exactly which format your browser will produce before you export, rather than promising MP4 everywhere.
Is the estimated size before export exact?+
It's a close approximation based on your chosen bitrate, duration, and whether audio is included — actual encoder behavior varies slightly frame to frame, so treat it as a strong estimate rather than a guaranteed final number.
Will audio always be kept if I check that box?+
Only if your browser supports capturing an audio track from an HTML5 video element (via captureStream) — this is broadly supported in modern Chrome, Edge, and Firefox, but if it isn't available the tool silently falls back to a video-only export rather than failing the whole job.
Why does compression take roughly as long as the video's own duration?+
The browser has to actually play the source video once, frame by frame, to draw and record it — there's no way to re-encode faster than real time using these browser-native APIs, unlike a dedicated desktop encoder.
What's the maximum file size and resolution I can compress?+
Uploads are capped at 100MB to keep in-browser memory usage reasonable. There's no hard resolution cap beyond that, but very high source resolutions will take longer and use more memory during processing.
Can I compress a video without changing its resolution?+
Yes — choose the Original preset to keep the source dimensions and use only the bitrate slider to shrink the file.
Because everything runs on canvas and MediaRecorder rather than a server-side transcoder, there's no queue, no upload progress bar, and no file leaving your machine — just a straightforward resolution and bitrate choice with a size estimate to guide it.
The WebM-vs-MP4 output difference is a genuine browser limitation, not a hidden catch — it's called out clearly in the tool itself so you know what you're getting before you download.