Video Converter

The input list covers what phones, cameras, screen recorders and older software produce: MP4 and MOV from phones, MKV from recording tools, WebM from browsers, AVI and WMV from older Windows programs, MTS and M2TS from camcorders, VOB from DVDs, MXF from broadcast cameras and FLV from early web players. Raw H.264 and H.265 streams are accepted as well, along with animated GIF, WebP, APNG and AVIF, and PowerPoint decks that you want to play as a slideshow.

On the output side the choice is smaller and more practical. The list holds the common video containers, four animated image formats for short loops, and PDF, which saves one frame per page when you need stills for a report or a storyboard. If what you actually want is the sound alone, the Video to Audio tool is the better tool, and for loops that will be posted in chats the Video to GIF tool has more control over size and colors.

A video file is a box with tracks inside. The box is the container, and its name is the file extension: MP4, MOV, MKV, WebM. The tracks are the picture and the sound, each compressed with a codec such as H.264, HEVC, VP9 or AV1 for video and AAC, MP3 or Opus for audio. When a phone says it cannot play a file, the problem is usually the codec inside, not the extension outside. MDN keeps a clear overview of both layers in its guides to media containers and video codecs.

This matters because a container accepts only some codecs. WebM holds VP8, VP9 or AV1 video, while MP4 and MOV are commonly paired with H.264 or HEVC. When you pick a target, the converter writes a matching pair. Leave Video codec on Auto and you get H.264 for MP4, MOV and M4V. Switch it when you know the device on the other end and want something more modern. The trade-off looks like this:

Sending a clip to someone. Use MP4 with H.264. It opens on iPhone and Android, plays inline in most chat apps and previews in email. iPhone recordings saved as MOV with HEVC are the usual reason a friend on Windows sees only a sound track or an error, which is the situation MOV to MP4 is set up for.

Uploading to a video site. Large platforms accept many formats and encode everything again on their side, so the goal is a clean master rather than a small file. YouTube's recommended upload settings list an MP4 container, H.264 video and AAC-LC or Opus audio, and they ask for the frame rate the video was recorded at. Keep Frame rate on Same as source and do not lower the resolution.

Putting video on your own web page. WebM with VP9 or AV1 and MP4 with H.264 are the two formats browsers handle well. Many sites offer both and let the browser choose. For short background loops, tick Remove audio; there is no reason to download a sound track nobody hears.

Editing. Apple editors such as iMovie and Final Cut are happiest with MOV or MP4. Files from camcorders (MTS, M2TS) or old cameras (AVI) are often easier to edit after converting them to MP4 first. Converting an MKV recording to MP4 is the most frequent case of this, and MKV to MP4 has the settings already filled in.

Old players and DVDs. MPEG and AVI are still on the list for set-top boxes, car screens and older software that ask for them by name. Check the manual or the list of supported files before choosing; these devices are strict and rarely explain why a file is refused.

Resolution sets the height of the picture in pixels, from 240p up to 2160p (4K); the width follows the original aspect ratio so nothing is stretched. Going down saves space and makes playback easier on older phones. Going up does not add detail that was never recorded, so leave it on Same as source unless a platform or device has a strict maximum.

Quality (CRF) runs from 0 to 51 and starts at 23. Lower numbers keep more detail and make larger files, higher numbers make lighter files with softer edges. The scale controls quality rather than size, so two videos at the same value can end up with very different file sizes. When the size itself matters more than the setting, tick Limit file size and enter a maximum in KB or MB; the converter then picks the bitrate for you.

Frame rate is best left alone. Lowering 60 fps to 30 fps saves space, but the change is visible on fast motion such as sports or gaming. Start at and End at let you keep a single part of the clip during the conversion, which saves a separate trimming step.

Under Audio you can drop the sound entirely, keep it as it is with Copy original, or convert it to AAC, MP3 or Opus at a bitrate between 96 and 320 kbps. The default of 192 kbps keeps music clean; speech needs less. For GIF and the other animated outputs there is a separate group with width, colors, dithering and looping, because those formats store frames as images rather than as video.

Start with the codec. A file that shows a black picture with sound, or sound with no picture, usually holds a video track the player cannot decode. Convert it again with Video codec set to H.264, which older Windows PCs, smart TVs and cheap Android phones all understand. Browser support for HEVC and AV1 in particular varies by browser, operating system and hardware; caniuse tracks the current state.

Next, check the sound. Some TVs and car systems refuse a file whose audio is Opus or a multichannel track even when the picture is fine. Set Audio codec to AAC, which is the most widely supported choice for MP4 and MOV.

If a website or form rejects the upload, look at its stated limits: many accept only MP4, set a maximum size, or cap the length. Converting does not change the length, so for long recordings combine the conversion with Start at and End at, or tick Limit file size. A clip that plays but looks blocky was probably encoded at a very low bitrate somewhere along the way; converting cannot restore that detail, so go back to the original recording if you still have it.

Finally, a file that will not open in the converter at all may be damaged or only partly downloaded. Try playing it in a desktop player such as VLC first. If it stops partway through there too, the missing part is gone, and the converter can only process what is left.