MP4 converter

1. Drop your videos in, or choose them: up to 20 at once. Each shows what it holds and what will happen to it.
2. Tick Make HEVC videos H.264 if they're from an iPhone and have to play on any PC.
3. Press Convert to MP4. Copies are quick; anything re-encoded takes about as long as it plays.
4. Download each MP4, or all of them at once. Files over 1 GB are saved straight to the place you choose.

A video file is a container (MOV, MKV, WebM, MP4) holding a picture and sound in their own formats. Changing the container is quick and lossless when the formats inside are ones MP4 holds; otherwise they have to be re-encoded.

MP4 with H.264 and AAC plays on every phone, computer and browser, and every editor and app takes it. AVI, WMV and FLV files can't be opened in a browser at all.

OBS used to record MKV by default, because a recording that's cut off (a crash, a full disk) stays playable, where an unfinished MP4 may not be. Since OBS 32.0, new profiles record Hybrid MP4 (Hybrid MOV on a Mac), which is just as safe, but profiles set up before then often still record MKV.

OBS can remux its own recordings too: File, then Remux Recordings, or Automatically remux to MP4 in the recording settings. This converter does the same for any MKV, on a computer without OBS, and several at once. Got a long stream? Cut it into parts with the video splitter, or see how to clip streams.

iPhones record HEVC (also called H.265), which keeps the same quality in less space. Copied into an MP4 it plays on phones, Macs and most browsers, but some Windows PCs need Microsoft's HEVC Video Extensions to play it, and some editors won't open it. Ticking Make HEVC videos H.264 re-encodes it to H.264, which plays everywhere, and makes the file bigger.

To record H.264 on an iPhone in the first place, go to Settings, then Camera, then Formats, and choose Most Compatible. To make a big file smaller after converting, use the video compressor.