Watermark Image Online

Watermark Image stamps text or a logo onto a base photo before you share it. The ToolSphere draws the base image on a canvas, overlays either fillText typography or a scaled watermark image with adjustable opacity and corner/center position, then exports JPEG, PNG, or WebP.

A watermark is a visible overlay composed into the final pixels. Text marks are quick for proofs; image marks match brand logos. Opacity and placement are the main readability levers once the base photo is chosen.

Text mode uses a bold system-ui font stack at your font size and color. Image mode scales the mark to a fraction of the base width while preserving the mark’s aspect ratio. Positions include top-left, top-right, center, bottom-left, and bottom-right with padding derived from image size.

Watermarks discourage casual reuse; they are not robust DRM. Anyone can crop or clone them out. Prefer translucent marks that remain readable without crushing the subject.

Photographers, teachers, and small shops mark proofs and social samples. Doing it locally keeps unpublished shoots off converter websites—The ToolSphere does not upload them for this tool.

Agencies send watermarked proofs before licensing finals. Local composition keeps unpublished galleries on the device during stamping for this tool.

• Text or image watermarks.
• Opacity and position controls.
• Font size for text; scale for logos.
• JPEG, PNG, WebP export.

For text, applyTextWatermark draws the base, sets globalAlpha from opacity, and fillText at the computed anchor. For images, applyImageWatermark draws the mark with drawImage at the scaled size. Encoding uses canvas.toBlob with your MIME and quality.

Image watermarks require a second file load. Transparent PNG logos work well because the canvas respects alpha while applying opacity. Because the mark is drawn in canvas space, resize the base first so logo scale matches the final frame—watermark after crop and rotate when possible.

If the mark is invisible, raise opacity or contrast against the photo. If it dominates, lower opacity or scale. JPEG quality affects the whole flattened result, including the mark.

If JPEG banding shows in smooth skies, raise quality. If a white text mark disappears on a bright sky, switch color or move position. Image marks that look boxed usually started from a non-transparent JPG logo—use PNG.

Visible ownership marks reduce casual scraping of portfolio previews. Flattening into pixels ensures the mark travels with the photo across apps that strip separate layers.

A watermark is not a substitute for licenses or contracts—it is a practical deterrent and proofing aid.

Padding ≈ 4% of the smaller base dimension. Image mark width = round(baseWidth × scale); height preserves mark aspect. Text uses measureText for width when right-aligning.

opacity

0–1 canvas globalAlpha for the mark.

fontSize

CSS px size for text mode.

scale

Logo width as a fraction of base width.

position

Corner or center anchor.

Watermark Image overlays text or a logo with opacity and position controls, then exports JPEG, PNG, or WebP from your browser. Mark proofs clearly, keep unmarked masters, and remember visible watermarks deter casual reuse rather than providing cryptographic protection.