How to add a watermark to a photo, without uploading it anywhere
- Tap Choose a photo and pick the picture you want protected.
- Type the watermark text — your name, CONFIDENTIAL, DRAFT, a date.
- Choose diagonal tiles across the whole image or one line in the corner.
- Set how strong the mark sits, then press Add the watermark.
- Save the result. Its name ends in -watermarked, so it never replaces the original.
A mark that survives forwarding
The default look is the classic proof stamp: mid-grey type at about a third strength, repeated diagonally so no crop can quietly remove it. Someone who wants to strip the mark has to retouch every tile by hand, which is exactly the friction you want between your file and someone else’s feed. Prefer one clear line in the bottom-right corner for title images and certificates — that layout is one tap away.
Size and strength are yours to set. The size dial is a percentage of the picture, so the same setting reads correctly on a thumbnail and on a full-resolution photo; the strength dial starts faint because a stamp that hides the picture defeats its own purpose.
Your photo stays on your device
Every other watermark site asks you to hand your picture to a stranger’s server first — the one file you most want marked is the one you have uploaded to somebody else. This page works differently: the browser you are reading this in does all of the work, and nothing is sent anywhere. Turn your Wi-Fi off after the page loads and it still runs.
That also makes it fast. There is no queue, no upload bar and no download step; the result appears as soon as your device can draw it, and a batch of twenty photos costs exactly as long as drawing twenty pictures takes locally.
What comes back
The output keeps your picture’s dimensions exactly, in the format you asked for — keep-the-original by default, or JPG, PNG or WebP when you need one. One honest note under the result says that letterforms come from your device’s own fonts: position, size and spacing are exact everywhere, while the exact shape of a letter can differ slightly from what your client sees on theirs.