Drop video files here or click to browse
Files queue into the current batch until you convert · MP4, MOV, MKV, WebM, M4V
If the destination is your own website, an HTML <video> tag, or a CMS that accepts WebM, MOV is the wrong starting format. MOV is great for archive and editing (heavy, container-rich, codec-agnostic) and the opposite of what a web page wants. WebM with VP9 is built for that use case: lean container, efficient codec, native browser playback.
In practice the saved bandwidth is meaningful. VP9 often produces smaller files than H.264 MP4 at matched perceived quality, with the largest gains on natural footage like talking heads or landscapes and smaller gains on heavy motion. Exact ratios vary with content.
Browsers with a supported VP9 encoder can perform this conversion locally. Drop in a folder of MOV clips, set a width if you also want to resize for the web, and get back WebM files without uploading the source.
VP9 is a generation newer than H.264 and often produces smaller files at matched perceived quality. The savings are largest on natural footage and smaller on heavy motion. Exact ratios vary with content.
Sources: MDN: Web video codec guide · Reviewed 2026-10-12
VP9 WebM is widely supported in current browsers, but older Apple devices and browsers can still need an H.264 MP4 fallback. Test the actual target devices before publishing.
Sources: MDN: Web video codec guide · Reviewed 2026-10-12
If the destination is a social platform uploader or a consumer editor, stick with MP4. They prefer H.264 even when WebM would be smaller. WebM is for self-hosted web video.
VP9 encoding can be slower than hardware-accelerated H.264 encoding. Actual speed depends on whether the browser and device expose hardware acceleration for the selected codec.
Sources: MDN: WebCodecs codec selection · Reviewed 2026-10-12
Premiere, Final Cut, and most social uploaders prefer MP4. Use MOV-to-MP4 for those destinations and reserve MOV-to-WebM for your own website.
Convert a folder of MOV files to WebM in your browser without uploading anything.
Drag and drop one or many MOV files into the queue, or click to pick them.
Output is preset to WebM. For web embedding, set width to 1280 or 1920 and pick the balanced quality preset.
Click Convert files. Each file is processed locally in your browser.
Download converted WebM files individually, or grab the whole batch as a ZIP.
No. The conversion runs in your browser; the file stays on your device.
Often noticeably smaller than the equivalent H.264 MP4 at matched perceived quality. The exact ratio depends on the source: talking-head video shrinks the most, fast action the least.
Current Safari versions support VP9 WebM, but support on older Apple devices is less consistent. For broad iPhone and iPad reach, ship an H.264 MP4 fallback alongside the WebM and test the devices you support.
Sources: MDN: Web video codec guide · Reviewed 2026-10-12
AV1 can provide better quality per bit than VP9, but encoding is more computationally intensive and hardware encoder support remains less common. VP9 is the more broadly practical output for this batch tool today.
Sources: MDN: Web video codec guide · MDN: WebCodecs codec selection · Reviewed 2026-10-12
Conversion requires WebCodecs video encoding and decoding, but each browser and device supports a different codec subset. MP4, MOV, and MKV output use H.264 video with AAC audio; Firefox and desktop Linux browsers do not natively encode AAC. Safari 16.4 added video WebCodecs, while Safari 26 added audio encoding and decoding. WebM output uses VP9 with Opus and may work where AAC output does not. For the widest support, use a recent desktop Chrome or Edge release, or Safari 26+. The converter still validates the actual source and output codec configuration when a job starts.
Sources: MDN: WebCodecs API · MDN: WebCodecs codec selection · WebKit: WebCodecs video support in Safari 16.4 · WebKit: WebCodecs audio support in Safari 26 · Mediabunny: supported formats and codecs · Reviewed 2026-10-12
Drop in MOV files, including HEVC iPhone clips, and get MP4s back in one pass.
Take heavy MKV captures from OBS and turn them into lean VP9 WebM ready for the web.
The browser runs the encoder directly, so there is no upload to a server.
Shrink a folder of videos in one pass, typically several times smaller, with little visible quality loss.