Image Watermark Tool

What the Image Watermark Tool Does

This overlays a text watermark on your image — a name, a website, a copyright line — to mark it as yours before you share it. You control the text, its size, how see-through it is, and where it sits.

The text is painted white with a subtle dark outline, a combination that stays readable whether it lands on a light or dark part of the photo. A tiled option repeats it across the whole image, which is harder to crop away than a single corner mark.

How It Works

Drop or pick an image and type your watermark text. Adjust the size, the opacity slider, and the position.

The image is drawn to a canvas and your text is stamped on top — at the chosen corner or centre, or repeated as a tile across the image at a lower opacity.

Download the result as a PNG. Nothing is uploaded; the watermarking happens entirely on your device.

Processing pipeline

1. Decode locally. Your image is drawn onto a canvas in the browser — never uploaded.
2. Set text and style. Your text is measured and styled in white with a dark outline at the size and opacity you pick.
3. Place the watermark. It is stamped at the chosen corner or centre, or tiled across the whole image at a reduced opacity.
4. Export the PNG. The watermarked image is saved as a lossless PNG.

Privacy

Your image is watermarked entirely in your browser and never uploaded — there is no server.

No account and no stored copy; the watermarked PNG exists only on your device.

Because the canvas re-encodes the image, the download also carries no EXIF or GPS metadata from the original.

Technical Details

Standards & references

• Visible watermark — An overlaid mark that declares ownership and deters casual reuse; unlike a forensic or invisible watermark, it can be cropped or edited out.
• Legibility styling — White fill with a dark outline keeps text readable over both light and dark areas of a photo.

Accuracy & Limitations

A visible watermark is a deterrent, not protection. It signals ownership and discourages casual copying, but it can be cropped off, painted over, or removed with editing software — and modern AI inpainting makes that easier than ever.

Placement changes how removable it is. A single corner mark is the easiest to crop away; the tiled option spreads the text across the whole image, so it is harder to remove cleanly without damaging the picture.

It adds text only — there is no logo or image watermark here. The default text is a placeholder; replace it with your own name, site or copyright line.

The output is a lossless PNG at the original dimensions, so the photo itself is not degraded by the watermarking step.

Real-World Use Cases

When to use it — and when not to

For provable ownership you need invisible or forensic watermarking, which this does not do; to remove hidden metadata before sharing, use the EXIF data remover.

Frequently Asked Questions

References

• Visible vs. Forensic Watermarking — Verimatrix
• HTMLCanvasElement: toBlob() (MDN)

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