Broad container support
MP4, WebM, MOV, MKV, AVI, FLV, TS and other common browser-readable containers all work as input.
Turn MOV, MKV, AVI, FLV and other common formats into universal MP4, WebM or MOV, with second-fast lossless MKV remux — key data processed locally, no watermark.
Privacy-sensitive steps are processed in your browser, and data is destroyed when you close the page.
Clean exports with no watermark or hidden marks added.
Runs right in your desktop or mobile browser — no download needed.
Sign in with your WUJIEE account to use it for free, watermark-free.
Privacy-sensitive steps run in your browser, and data is destroyed when you close the page. Work on private footage, business assets and course recordings with confidence.
MP4, WebM, MOV, MKV, AVI, FLV, TS and other common browser-readable containers all work as input.
MP4 (H.264+AAC, best compatibility, with high-quality/balanced/smaller-size presets), WebM (VP8+Vorbis) or MOV (H.264+AAC).
MKV output only swaps the container — no re-encoding, lossless quality, done in seconds.
Sign in and upload a video file
Pick the output format and quality preset
Convert and download
Drop the MOV into the Convert Video tool in WUJIEE Video Tools and pick MP4 as the output. iPhones record MOV (often with HEVC inside), which Android phones, older TVs and many Windows players can't open; MP4 (H.264+AAC) has the best compatibility and plays on phones, computers and the web. Conversion runs in your browser with key data processed locally, and exports carry no watermark.
MKV output is a remux — it only swaps the container without re-encoding, so it's fully lossless and finishes in seconds. Converting to MP4/WebM/MOV re-encodes: the high-quality preset is visually near-identical, while the smaller-size preset trades a little quality for size, so pick by purpose.
When in doubt, pick MP4 (H.264+AAC) — it plays everywhere. WebM suits web embedding; if you only want to swap the container and keep quality untouched, choose MKV remux, which finishes in seconds.
WUJIEE Video Tools uses ffmpeg.wasm (the WebAssembly build of FFmpeg) to transcode in your browser: key data is processed locally, your data is destroyed when you close the page, and there is no server-side size limit. MKV remux is seconds; re-encoding takes roughly 0.5–2× the video's duration depending on your device.
16 online video tools: compress, trim, convert, turn videos into GIFs, add watermarks and more.
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