Compress a video to a smaller file locally in your browser - choose resolution and quality. The video never leaves your device. No upload.
Running locally on your device ...
Running locally on your device ...
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Your files never left your device
Continue with this file
No re-upload neededThese tools accept .MP4 - your file is handed over directly.
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Videos get huge fast, and then they no longer fit into an email attachment, blow past a portal upload limit, or take forever in a messenger. This tool re-encodes your video into a much smaller file by scaling the resolution down and lowering the bitrate. The result is an MP4 file with H.264 that plays practically everywhere - on a phone, in the browser, and in every common player.
The quickest way is a preset: "Best quality" keeps the original resolution and only lowers the bitrate, "Balanced" scales to at most 720p, "Smallest file" to at most 480p. Under "Custom settings" you set the maximum height (2160p (4K), 1080p, 720p, 480p or 360p, or keep the original resolution) and the quality level yourself. The tool only scales down, never up, and keeps the aspect ratio. The actual encoding is done by your browser native video encoder through the WebCodecs interface - fast and without loading a codec library from a foreign server.
The crucial point: everything runs locally in your browser, the video is not uploaded. That is exactly what sets this tool apart from many online compressors that send your - often private - videos to foreign servers. An existing audio track is carried over as long as the browser can encode a matching audio codec. Because it is re-encoded, the compression is lossy; a lower level saves more space but visibly costs quality.
Anyone who needs a fixed ceiling instead of a quality level - say, because an upload portal allows exactly 25 MB - can instead turn on "Limit to a target size" and enter the desired size in MB. The tool reads the video length and computes the matching video bitrate from it, reserving a fixed share for the audio track. The result usually lands close to the target size, but it is an estimate from a single encoding pass, not a hundred-percent guarantee - leave some buffer for tight targets.
Many free online compressors cap the file size at a few hundred megabytes, require an account or subscription for higher resolutions, or add a watermark. None of that applies here: compression is unlimited, free and watermark-free, because encoding runs entirely in the browser - on any device with a modern, WebCodecs-capable browser, from a Windows PC to a smartphone.
| Input formats | MP4, M4V, WEBM, MOV, MKV |
|---|---|
| Auto-conversion | PNG, GIF |
| Output format | MP4 |
| Batch processing | No |
| Processing | Locally in your browser (WebCodecs) |
| File upload | None |
Limitations: The tool re-encodes (lossy) and only scales down. It needs a modern browser with WebCodecs (recent Chrome, Edge or Safari); if that is missing, it says so honestly instead of silently doing nothing. An audio track is carried over if its codec can be encoded, otherwise it is dropped. Very large files (over 1 GB) are rejected (the browser tab's memory limit while streaming; without that support it is already about 600 MB). The target size is an estimate from a single encoding pass (no second check round): it reserves 128 kbps for the audio track and usually lands close to the actual file size, but not exactly on the byte - if a target is too small for the video length, the tool honestly reports that instead of producing an unusable file.
| Preset | Resolution | Quality | Use |
|---|---|---|---|
| Best quality | keep original | High | barely visible loss |
| Balanced | max 720p | Medium | good default for most purposes |
| Smallest file | max 480p | Low | smallest file, chat/messenger |
No. Compression runs entirely locally in the browser; the video never leaves your device - that is the whole point.
It depends on resolution and quality. 720p at medium quality is often a good compromise between size and picture.
An MP4 file with H.264. This format plays on almost every device and browser.
A modern browser with WebCodecs (recent Chrome, Edge or Safari). If support is missing, you get a clear message.
Close, but not exact. The bitrate is computed from a single pass, not a second verification encode - leave some buffer for very tight targets.
Yes, as long as the mobile browser supports WebCodecs (such as recent Chrome on Android) - the video stays just as local as on desktop.
No. No watermark, no daily limit, no account - only the file size is bounded by your device memory (see limits above).
Yes. Unlike online compressors that upload files to a server, your video stays exclusively on your device here - try airplane mode.
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