Video Converter - Free Online Tool

Who Uses Video Converter

Use it when: an iPhone MOV won't play on Windows or Android, a WebM download needs to go into an editor that only takes MP4, an OBS recording saved as MKV needs sharing, or a website needs a WebM version of an MP4.

Video Converter Features

• Instant when possible — Compatible videos are repackaged, not re-encoded: seconds, and no quality loss.
• MP4, WebM, MOV, MKV — Convert between the four common formats, with H.264/AAC MP4 for playback everywhere.
• Never uploaded — Your browser does the conversion, so private videos stay on your device.
• Batch + ZIP — Convert several videos in one go and download them together.

How to Use Video Converter

Three steps, nothing uploaded.

1. Drop your videos — MOV, WebM, MKV, MP4 - one or several.
2. Pick a format — Each file shows whether it'll be an instant repackage or a re-encode.
3. Convert and download — Preview, then download each video or all as a ZIP.

Frequently Asked Questions

Containers and codecs: why some conversions are instant

A video file has two layers. The outer layer is the container, the format the file extension names: MP4, MOV, WebM or MKV. Inside it are the streams, the actual compressed picture and sound, each encoded with a codec such as H.264, HEVC, VP9 or AV1 for video and AAC or Opus for audio. The container decides which codecs it can hold and how players find them; the codecs decide the quality and the size.

That split is what makes many conversions instant. MOV and MP4 are close relatives, and both hold H.264 video and AAC audio. Turning such a MOV into an MP4 does not require touching the picture at all: the streams are copied byte for byte into the new container. The same applies to MKV, which accepts almost any codec. These repackaging conversions, also called remuxing, finish in a second or two even for long videos and lose nothing.

A real re-encode is needed only when the target container, or the devices you want it to play on, expect a different codec. WebM is defined around VP9, VP8 and AV1 video with Opus audio, so an H.264 MP4 has to be re-encoded to become a WebM. In the other direction, this converter makes MP4s with H.264 and AAC, because that combination plays on every phone, computer, smart TV and website, even though the MP4 container could technically hold other codecs.

How the conversion runs in your browser

When you add a video, the converter reads its container and identifies the codecs inside, then shows for each file whether converting to your chosen format will be an instant repackage or a re-encode. Change the target format and the labels update, so you can see the cost before you start.

Repackaging reads the compressed packets from the original and writes them into the new container with the timing and metadata it needs, which is limited only by how fast your device can read the file. Re-encoding decodes every frame with the browser's built-in video decoder and encodes it again with its built-in encoder, usually on your graphics hardware, at a high quality setting. Audio is converted the same way: copied when the target accepts it, re-encoded to AAC for MP4 and MOV or Opus for WebM when it does not.

Everything happens on your device. The file is never uploaded, there is no server queue and no account, and the result is held in memory until you download it. Convert several videos at once, check each one in the preview, and save them individually or together in a single ZIP with clash-free names.

Timing and sync are preserved throughout. Repackaged files keep the original frame timestamps exactly, so audio stays in step and variable-frame-rate phone recordings play just as they did. Re-encoded files keep the original frame rate and resolution, and the audio is aligned to the same timeline. If a video uses a codec your browser cannot decode at all, which is rare with files from phones, cameras and screen recorders, that file is reported as failed and the rest of the batch carries on.

Choosing the right format

If you are not sure, choose MP4. It is the format every phone, computer, browser, smart TV, social network and video editor expects, and an H.264 MP4 with AAC audio is about as universally playable as a video file can be. It is the right choice for sharing a phone video with someone on a different platform, uploading to a website or social network, or importing into almost any editor.

Choose WebM when you are publishing video on your own website and want an open, efficient format alongside or instead of MP4; every current browser plays it. Choose MOV for Apple workflows: Final Cut Pro, iMovie and QuickTime all prefer it, and MOV can keep HEVC video for smaller files on Apple devices. Choose MKV when you simply need a different container and want every stream kept exactly as it is, which is common with screen recordings from OBS.

Converting does not make a video smaller by itself unless it is re-encoded, and even then the goal is to preserve quality rather than shrink the file. If you need a video under a size limit for email or chat, convert it to MP4 first if necessary and then use the video compressor, which targets an exact size. And if you only need part of a video, trimming it first makes every later step faster.

Finally, keep the original until you have checked the result. Use the preview to make sure the converted file plays and looks right, rename it if you like, and only then delete the source. Because the converter never uploads anything, you can repeat a conversion with a different target format as often as you need, and switching from MP4 to MKV or back takes only seconds whenever the codecs allow a repackage.