WebM to MP4 runs automatically here: drop videos anywhere on this page and each becomes an MP4, an instant lossless rewrap when the codecs inside are MP4-compatible or a hardware-speed H.264 re-encode when they aren't. The result note on each card says which happened. No upload, no size caps, no signup.
Why your screen recording came out as WebM
Browser-based screen recorders, Loom-style tools, Chromebooks and most "save video" buttons on the web produce WebM, because it's the format browsers can write natively. The web loves it. Almost nothing else does: iPhones won't play it, smart TVs shrug at it, and Premiere and Final Cut won't even import it. MP4 with H.264 is the one container the whole world agreed on, so that's what you get here.
Rewrap when possible, re-encode when needed
WebM files carry VP8, VP9 or sometimes H.264 video. When it's already H.264, we copy the bits straight into an MP4 container: identical quality, finished in seconds. When it's VP8 or VP9, MP4 players won't decode it, so we re-encode to H.264 using your machine's hardware encoder, which chews through video far faster than any upload-convert-download round trip. A 2 GB recording would spend half an hour just uploading to a converter site. Here the conversion is often done before that upload would have reached 5%.
FAQ
Is there a file size limit?
No hard cap. Long multi-GB recordings work best on a computer in Chrome.
How do I know if it rewrapped or re-encoded?
Each finished card says so. Rewrapped files are bit-identical quality. Re-encoded files target visually identical quality at a healthy bitrate.
Is my recording uploaded?
Never. Your video is never uploaded, stored, or seen by anyone. Everything happens instantly and privately on your own hardware, which is exactly why there's no progress bar crawling through an upload.