How to watermark a short video
1. Drop one video you already have. Audio-only files and pictures are refused here. 2. Leave the words as DRAFT, or type your own line and pick white or black. Or switch Watermark to Logo image and choose a PNG, JPG or WebP. 3. Pick center, bottom right or top left, and a strength. 4. Press “Add watermark” and download the MP4.
The words are drawn in this tab, because the FFmpeg build in the browser has no text filter. FFmpeg then stamps that picture onto every frame. A logo is scaled and overlaid by FFmpeg directly. Either way the picture is re-encoded, so keep the original until the download looks right.
A moving mark, not a photo stamp
Watermark image draws on a still photo. This page follows the clip. Trim video is how you get under the length limit before you stamp. Add text to image is the still caption, with no soundtrack.
The clip stays in this tab
The first visit downloads FFmpeg. Later visits reuse the browser cache. Clips longer than the limit on the page are refused, because every frame is re-encoded here. GustKit does not fetch video from a link.
How to check the mark before you replace the clip
1. Play the download and pause on a bright frame and a dark frame. The line should stay readable on both. 2. If the logo covers a face, switch placement to a corner and run again. 3. Keep the original until the edges of the picture still match.
Text is drawn in this tab and FFmpeg stamps that picture. A logo is overlaid by FFmpeg. The clip is re-encoded, so a long file is refused. Trim video is how you get under the limit. Nothing is uploaded.