Image Watermark Adder

Mark an image as yours — without handing it to a website first.

Drop an image here or click to choose a file — the image you want to watermark

Runs in your browser. Everything you type or load here is processed locally by JavaScript on this page. Nothing is uploaded to Tooltrusty or to any third party.

What the image Watermark Adder does

A watermark is a claim of authorship printed onto the image itself, so it survives being screenshotted, re-saved and re-posted in a way that a metadata credit does not. This tool applies either a text watermark or a logo image, composites it onto your picture with the Canvas API, and gives you back a PNG.

The controls cover the decisions that actually matter. Position offers the nine standard anchor points; bottom right is the default because it is where viewers expect a credit and where it is least likely to sit over the subject. Opacity is the setting people get wrong most often — somewhere between 40% and 60% is usually right, visible enough to read but not so heavy that it competes with the image. Size is set as a percentage of the image, so the same setting works on a thumbnail and a full-resolution photo. Rotation is mainly useful for a diagonal mark.

The tiling option repeats the watermark across the entire image on a diagonal. It is far harder to crop or clone out than a single corner mark, which makes it the right choice for proofs and preview copies that you are sending to a client before payment. It is the wrong choice for a portfolio piece, where it destroys the image you are trying to show off.

For a logo watermark, a PNG with a transparent background gives much the best result — a logo on a white rectangle will stamp that rectangle onto the photo. Output is always PNG, so the watermark edges stay crisp; run it through the Image Compressor afterwards if you need a smaller file.

How to use it

  1. Load the image you want to protect.
  2. Choose a text watermark and type your credit, or switch to the Logo tab and load a transparent PNG.
  3. Set position, size and opacity — around 50% opacity in a corner suits most published images.
  4. For proofs sent to clients, tick Tile so the mark cannot easily be cropped out. Then download.

A worked example

Two very different jobs, from the same photograph:

PurposeSettingsWhy
Published portfolio imageText, bottom right, 5% size, 45% opacity, no tilingReadable credit that stays out of the composition
Client proof before paymentText, tiled, 6% size, 30% opacity, −20° rotationCovers the whole frame so it cannot be cropped away, but light enough to judge the picture
Brand asset for socialLogo, bottom left, 18% width, 80% opacityA logo reads as branding rather than as a defensive mark

The tiled proof is the case people underestimate. A single corner watermark takes about four seconds to crop off; a tiled one at low opacity across the whole frame cannot be removed without visibly damaging the image.

Frequently asked questions

Does a watermark stop people stealing my photo?

It raises the effort and makes casual reuse obviously attributable, which is often enough. It is not absolute — a determined person can crop, clone or inpaint one out. Tiling makes that meaningfully harder; a small corner mark barely slows it down.

What opacity should I use?

For published work, 40–60% is the usual range: legible without dominating. For proofs where deterrence matters more than looks, 25–35% tiled across the frame works better, because it covers everything without obscuring detail.

Why does my logo have a white box around it?

The logo file has a solid background rather than a transparent one. Use a PNG with real transparency; if you only have a JPEG logo, the white background is baked into the file and cannot be removed by this tool.

Does watermarking change the original file?

No. The tool builds a new image in your browser and offers it as a download. Your original file on disk is untouched, and nothing is uploaded at any point.