How to use Browser Video Compressor

Select a video and note its original file size.
Choose Longest output side and Requested video bitrate; a smaller image and lower bitrate can reduce size.
Run the job with the tab visible, then compare the reported input and output bytes.
Review text, movement and sound in the WebM before replacing any copy of the source.

Example: Browser Video Compressor

Compare a modest bitrate with the size of a small source clip.

You add

Source: a two-second, 640 × 360 supported video. Longest output side: 320; Requested video bitrate: 600 kbps.

You get

The WebM frames are 320 × 180. Its report states the actual bytes and whether they are fewer than the input; a smaller file is not guaranteed.

Options

Longest output side (pixels): The longest dimension is reduced to this value when necessary. Smaller inputs are not enlarged. The other dimension follows the source aspect ratio.
Requested video bitrate (kbps): This is a requested encoder bitrate in kilobits per second. It can affect detail and file size, but the browser may not meet the exact request.

Supported inputs and limits

Requests a bitrate and downscaled frame size. A smaller file is not guaranteed; compare the reported byte sizes. Use a browser-decodable MP4/MOV-family or WebM with one video track and at most one audio track. Total selected input: 256 MiB; source frames: 8,294,400 pixels (4K). Sources may be up to 60 minutes, but whole-clip jobs require a clip of 10 minutes or less. Selected or combined output: up to 10 minutes and 128 MiB, 2,073,600 pixels (1080p) and 1,920 pixels per side. Recording runs in real time and the page must stay visible. WebM export re-encodes the media, so quality, frame timing and sound timing depend on the browser and device. Metadata, subtitles and extra tracks are not preserved. Seek cues are not built; check playback before using the file. Larger jobs need more device memory.

Where your input is processed

This tool processes your input in this browser. Your text and files are not uploaded to UseFreeTools. Check this tool's limits for anything it may save on your device.

Judge the result by bytes and visible detail

A lower requested bitrate does not ensure a smaller download. The source may already be compressed more efficiently, and containers and audio add their own bytes. Compare the actual size report with the source, then inspect fine text and motion. A small file that loses essential detail may not be useful.

Choose dimensions before repeatedly lowering bitrate

Reducing dimensions removes pixels and may make a modest bitrate more usable. The resize only goes downward and stays inside the output pixel limit. This is a new WebM recording, so original codec, metadata and subtitle tracks are not retained. The tool does not optimise long movies or run a server compression job.

Questions about Browser Video Compressor

Can a compressed export be larger than its source?

Yes. Different codecs, source quality and requested settings can increase size; the result reports that honestly.

Is the requested bitrate exact?

No. Native recording chooses actual encoding behavior, which may differ from the request.

How should I check the result?

Compare the reported bytes, then play the download to check motion, sound and visible quality.

Project manager: Tony Hines · Content updated 4 October 2026 · Report a problem

Browser Video Compressor

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