Add a watermark to a video

How to add a watermark to a video in your browser

Add your name or logo to a video without uploading it. The video watermark tool at the top of this page reads your file on your device, draws the mark on every frame and saves a new video. Your original is left as it is.

What your browser needs

The tool relies on WebCodecs, the browser feature that encodes and decodes video on your own device. According to caniuse, about 95 percent of browsers worldwide support it fully or partly. Chrome and Edge from version 94 work, and so does Firefox from version 130 on computers. Safari works from version 16.4, but it handles video only until Safari 26 adds audio. Firefox on Android has no WebCodecs, so use Chrome there. The tool checks your browser and your file before it starts, and tells you if something will not work.

Formats and audio

You can add MP4, MOV and WebM files. MP4 and MOV files are saved as MP4, and WebM files are saved as WebM. Staying in the same family means the sound can usually be copied across untouched, because its format fits the new file. When the sound has to be re-encoded, the page tells you before you start. We never drop it silently.

The picture is different. Adding a mark means every frame is decoded, drawn on and encoded again, so the new file can differ from the original in size and in quality.

What the page checks first

Before it converts anything, the page reads your file and shows how long it is. It stops and tells you if the file cannot be read, if your device has no encoder for it, or if the sound cannot be carried across. Once a conversion is running, you can cancel it at any time.

Length, size and speed

Your device does the work, so your device sets the limits. We have no independent speed measurement for full-size video, so we make no promise. Our own estimate is that a computer with hardware video encoding finishes in about the length of the clip or less, and that a phone takes longer. Above 1080p, or on a phone, the page warns that 4K processing may be slow or fail, and asks you to keep the tab in the foreground.

Where the browser allows it, the result is written to disk as it is produced, so memory is not the limit. Otherwise the tool tells you before it starts if a video is too large for your device to hold.

Placing the mark

The mark is laid out once against the video's displayed size, so a portrait clip from a phone gets the mark where the preview shows it. Keep it inside a margin, because apps and players often draw buttons and captions over the edges of a video. Text may need the outline or the shadow on moving footage, because the background changes under it, and a logo with a transparent background keeps the picture clear. The preview never plays sound on its own. For ideas on logo size and position, see the logo watermark guide.