Video Compressor

Compress videos locally with quality presets, powered by a multi-threaded ffmpeg WebAssembly core. Files never leave your device.

🔥 A local Video compression tool — your files never leave your device. Zero privacy risk. Video Compressor runs a full ffmpeg build compiled to WebAssembly inside your browser. Your video is decoded, re-encoded and saved entirely on your own machine — there is no server, no account, and no upload. Nothing about your file ever goes over the network. HOW IT WORKS 1. Click the toolbar icon. The compressor opens in its own tab. 2. Drop in a video, or click to pick one. 3. Choose a quality preset and, if you want, cap the resolution or frame rate. 4. Press Compress, then download the result as MP4. FEATURES • 100% local processing — powered by ffmpeg.wasm, nothing is uploaded • Multi-threaded encoding core, with an automatic single-threaded fallback • Three quality presets: HD (quality first), Balanced (recommended), Small (size first) • Resolution cap: keep original, 1080p, 720p or 480p — downscale only, never upscaled • Frame-rate cap: keep original, 60, 30 or 24 fps — downscale only, no duplicated frames • Portrait-aware scaling: "720p" caps the short side, so phone footage keeps its detail • Keep or drop the audio track • Output: MP4 (H.264 + AAC), with faststart so it plays instantly on the web • Before/after size comparison, plus how much you saved • Reads the source duration, resolution and real frame rate so caps only apply when they help • Your last settings are remembered for the next run • Light and dark theme • English and Simplified Chinese GOOD TO KNOW • Up to 700 MB per video. Very high-resolution sources (4K and above) are memory-heavy; if a run fails, cap the resolution at 720p and try again. • Compression happens in the tab you opened, so keep that tab open until it finishes. --- Questions or feedback? Reach us via the email button on the extension page.