Free Online Video Converter

How to choose a container and a codec

Start from the destination, not from the file name. A phone, a chat app, a video editor and a web page each accept a different set of containers and codecs, and the extension alone cannot tell you whether the receiving player can decode what is inside. Pick the output first: MP4 with H.264 when you do not know where the file will end up, MOV for Apple tools that expect QuickTime, MKV when a desktop player has to carry several tracks, WebM for a page you control, GIF for a short silent loop.

The codec follows the container. This converter writes H.264 into MP4, MOV and MKV, VP8 into WebM, and a 256-colour palette into GIF, because each of those is the pairing its target player is most likely to open.

Two shortcuts do not work. Renaming a file from MKV to MP4 changes nothing inside it, and re-encoding an already compressed video at a higher rate cannot restore detail that was thrown away. Both failures look like a broken converter when they are really a mismatched pair.

Why processing locally is safer than uploading

An upload means a copy of the file leaves your machine and lands on somebody else's disk, subject to their retention policy, their account terms and the length of their queue. Many converters keep a file for a while so that a failed job can be retried, and none of that is visible from the page you are looking at.

Here the browser opens the file, your own processor decodes it, and the result goes straight to your downloads folder. The only thing downloaded is the conversion engine itself, about 31 MB, cached after the first use. There is no account, no watermark, no size cap, and no server that could hold a copy it never received.

The trade-off is memory. A server can throw hardware at a four-gigabyte file; a laptop cannot. What you get in exchange is that nothing about the clip has to leave the device to be converted.

Format matrix: every pair in one place

The video format matrix lists the container and codec pairs this site can actually perform, with the method each one uses and the job it suits. A pair without a page is marked as unavailable instead of being offered as a button that cannot work.

Use it when a file will not open and you are not sure whether the container or the codec is at fault. It also shows which pairs have a dedicated page with their own settings: a trim for GIF, CRF levels for compression, a browser decoder for AV1.

Work with your browser and device

Conversion takes place on your device. The browser downloads the conversion engine when needed, so the first use may take longer than a later conversion in the same tab. Your selected video is read locally for processing.

Processing time depends on the device, the input, and the chosen settings. Large videos can require substantial browser memory. If the page runs out of memory or the result fails, close other demanding tabs, try a smaller source, or use a desktop tool for a large or complex file.

Where to go for other jobs

This page converts to MP4, MOV, MKV, WebM or GIF. When a job needs its own settings, the dedicated page is the shorter route: MP4 to GIF adds a trim, frame-rate and loop controls, the compressor exposes CRF levels, and HEVC to H.264 and AV1 to MP4 handle codecs this general menu does not name.

The format comparison page explains the difference between containers and codecs and shows which dedicated tools are available.

When the output is not what you expected

If the download is the wrong length, check the trim values for a GIF, or the duration of the source for a video. A file that stops early is usually a source that was already short, or a conversion that ran out of memory near the end.

If the output looks worse than the source, the size setting explains most of it: 480p throws away three quarters of a 1080p frame. That is a deliberate trade for a smaller file, not a fault. If the colours look flat, that is the GIF palette, which stores 256 colours per frame and cannot hold a gradient.

If an app refuses the file, its own limits come next: maximum size, maximum duration, an allow-list of containers. A browser converter cannot override those rules. When the file is accepted but shows the wrong shape, the source may carry a rotation flag that the receiving player ignores.