Secure Local Image Watermark Adder

Renting a flat, opening a bank account, applying for a credit card or registering for an event often means sending a photo of your ID card, passport or bank statement. If that image leaks, it can be used to open phone lines, take out loans or create accounts in your name. Adding a watermark that says what the copy is for is widely recommended by banks and security teams: even if the file is forwarded, its purpose and date are written across the image, making it hard to reuse.

The tool includes one-click preset texts such as “For official use only, copy invalid”, and you can type your own, for example “For XYZ Ltd tenancy application only, Oct 2026”. Stating the purpose, recipient and date makes misuse much harder. Font, color and size (10–100 px) are adjustable. Besides text, you can upload a logo image as the watermark, which suits copyright marks on photography, product images and design drafts.

Tile mode is on by default and repeats the watermark diagonally across the whole image. That is the recommended setting for ID copies, because a single line in a corner is easy to crop out or retouch away. Opacity defaults to 30% and rotation to −30°, keeping the mark readable without hiding the document’s details. Turn tiling off to place a single watermark at a chosen position, which works better for portfolio images.

The result is exported as a PNG download. Everything is processed with Canvas in your browser and the photo is never uploaded to a server, which matters especially for sensitive documents like ID cards. Note that a watermark greatly reduces the risk of misuse but cannot fully stop a skilled retoucher, so always confirm that the recipient and channel are trustworthy before sending ID documents.