How this MPG to MP4 converter works
MPG and MPEG files come from older camcorders, DVDs and TV recordings, and many phones and browsers cannot play them. This converter rewrites the file as a standard MP4 with H.264 video and AAC audio at 128 kbps, which plays almost everywhere. The video is re-encoded, not just renamed.
Only the first video and audio stream are kept, because MPG sources often carry data or subtitle streams that MP4 cannot hold. The MP4 is laid out so it can begin playing before it has fully loaded. If your browser cannot decode the source with the built-in hardware path, the work falls back to WebAssembly (ffmpeg.wasm), which is slower but gives the same kind of result. A progress bar shows how far the conversion has got. The finished MP4 is a normal file that you can download and keep, while your original MPG file stays untouched on your device.