Frequently Asked Questions

Why doesn't my MKV file play?

MKV (Matroska) is a container format, not a codec. Web browsers (Chrome, Firefox, Safari) do not include a parser for the MKV container. Even if the video inside the MKV is a standard H.264 stream that the browser *can* play, it doesn't know how to unbox it.

Solution: You can quickly remux (change the container without re-encoding) an MKV to an MP4 using a command-line tool like FFmpeg: ffmpeg -i input.mkv -c copy output.mp4. This process takes seconds because it doesn't alter the video data.

Is there a file size limit?

Practically, no. Because uMediaPlay uses URL.createObjectURL(), the browser doesn't load the entire massive file into RAM at once. Instead, it streams it directly from your hard drive to the video element as needed. We have successfully tested 4K files exceeding 50GB. The only limit is your OS file system restrictions.

Does it support subtitles (.srt, .vtt)?

Native browser video elements support WebVTT (`.vtt`) subtitles natively via the <track> element. However, loading external side-car subtitle files (like a separate `.srt` file from your hard drive) alongside a local video file requires explicit user permission to read two separate files and parse them client-side. We are working on a dedicated subtitle parsing implementation for a future update.

Can I use this on an airplane without WiFi?

Yes. uMediaPlay is designed as a static site and can function entirely offline. If you load the page before losing connection, it will work. Additionally, it supports installation as a Progressive Web App (PWA). Once installed to your device, it requires zero network connection to function.

Are you tracking my files?

No. We physically cannot. The code that reads the file runs entirely within your browser on your machine. There is no server-side component processing your media. See our Privacy Policy.