No. Files are opened entirely in your browser using local JavaScript and WebAssembly. Nothing is sent to a server.

Does it work on mobile?

Yes. The viewer is mobile-first and works on phones, tablets, and desktops.

Video.mp4 · .m4v

MP4 (inspect) viewer

ready

MP4 (inspect) · .mp4 · .m4v

MPEG-4 container with metadata inspection.

Choose a fileor paste · ⌘V

About MP4 (inspect)

MPEG-4 container with metadata inspection.

MP4 is everywhere — videos, podcasts, ML datasets. We pair native playback with mp4box.js for deep box-level inspection.

FAQ

What is a MP4 (inspect) file?: MP4 is everywhere — videos, podcasts, ML datasets. We pair native playback with mp4box.js for deep box-level inspection.
Is my file uploaded?: No. Files are opened entirely in your browser using local JavaScript and WebAssembly. Nothing is sent to a server.
Does it work on mobile?: Yes. The viewer is mobile-first and works on phones, tablets, and desktops.