Convert MPEG to MP4 Free Online
Convert legacy MPEG-1 or MPEG-2 videos to modern, universally playable MP4. Processes entirely in your browser without uploading to any server.
If you found an old .mpg file on a CD, DVD export, camera archive, or VHS capture, it may still open in VLC but fail in a browser, phone gallery, or smart TV app. That usually happens because MPEG-1 and MPEG-2 are legacy video formats, while modern web playback expects a more compatible container and codec combination.
MP4 with H.264 video and AAC audio is a safer everyday format for viewing, sharing, and uploading. It gives your old MPEG file a format that modern browsers and devices understand more consistently.
This converter is built for the practical case where you want an access copy, not a preservation master. If you are archiving family tapes or client footage, keep your original MPEG file too, then use the MP4 for playback and sharing.
FFmpeg.wasm is a WebAssembly port of FFmpeg, so the conversion engine runs inside your browser instead of on a remote server. That is the reason your video can stay on your device from start to finish.
The tradeoff is speed. Browser-based FFmpeg.wasm conversion depends on your CPU, browser memory, file size, and video duration. A short MPEG clip may finish quickly, while a long DVD-style MPEG-2 file can take noticeably longer.
The benefit is reliability. Instead of relying on a narrow browser codec path, GrepCut uses FFmpeg.wasm to decode and transcode legacy MPEG input into a more useful MP4 output.
Can you convert MPEG to MP4 without uploading the file?
Yes. GrepCut uses FFmpeg.wasm in your browser, so your MPEG file is processed locally on your device. You do not need to upload the video to a server.
Why does your MPEG or MPG file play in VLC but not in a browser?
VLC includes broad codec support, while browsers only support certain container and codec combinations. Converting your file to MP4 with H.264 video and AAC audio makes it easier to play in Chrome, Safari, Firefox, Edge, iOS, and Android.
Will converting MPEG to MP4 reduce quality?
The converter transcodes the video, so it is not a lossless remux. GrepCut aims to preserve the visible quality while producing a practical MP4 file, but you should keep your original MPEG file if it is your only archive copy.
Why is browser conversion slower than some desktop apps?
FFmpeg.wasm runs inside your browser through WebAssembly and uses your device resources. That keeps the process private and installation-free, but long MPEG-2 files can take more time than GPU-accelerated desktop encoding.
Is MPG the same as MPEG?
For this converter, you can treat .mpg and .mpeg as the same source family. .mpg is the older short file extension, while .mpeg is the longer version. Either one may contain MPEG-1 or MPEG-2 video.
Can you use the MP4 on your phone after conversion?
Yes. The goal of converting to MP4 is to create a more mobile-friendly file. After conversion, you can move the MP4 to your phone, add it to a gallery, send it in a message, or upload it to a platform that accepts MP4.
Should you delete the original MPEG after converting?
Only delete it if you are sure you no longer need the source. If the MPEG file is a family video, client recording, or archive copy, keep the original and use the MP4 as your convenient playback version.