This video watermark tool supports two practical marks: a short text label such as a creator handle, or a JPG, PNG, or WebP logo. Nine position presets keep placement consistent from frame to frame. Size is relative to the video width, while opacity is baked into the overlay so the exported result matches the preview closely.
The browser first turns either watermark type into a transparent PNG. FFmpeg WebAssembly then overlays that image across the full video, writes H.264 picture data, and keeps the first readable audio track as AAC. Subtitles, extra tracks, chapters, and source metadata are not copied. The engine downloads only when export starts; your media files are not sent with that request.