CapyStamp · tool no. 13
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Watermark one photo or a whole batch, in your browser. Nothing uploaded.
CapyStamp adds a text or logo watermark to one photo or up to twenty at once, at full resolution, without uploading them.
Updated · by Unfolding Dimensions
01 · The photos
Nothing uploaded — the stamping happens in this tab.
02 · The mark
The halo is a soft shadow or thin outline — it keeps the mark readable on busy photos.
Bottom right — drag the preview to fine-tune.
Presets
Saved in this browser only — a preset is the design, never your photos or logo.
03 · The preview
DemoA demo — drop a photo to stamp your own.
Your photos never leave this tab.
The guide
How to add a watermark to your photos
- Step 1
Drop one photo, or up to twenty at once.
- Step 2
Choose a text mark or your logo, then set its size, opacity, rotation and position — drag it, nudge it with the arrow keys, or tile it in a grid or diagonally.
- Step 3
Pick PNG, JPEG or WebP and download each photo, or the whole batch as a ZIP.
CapyStamp places your watermark relative to each photo rather than in fixed pixels: its size is a share of the photo's short side and its position is one of nine anchors. The same design lands in proportion on portrait, landscape and square shots in one batch.
The preview and the export are drawn by the same code, with the fonts loaded before anything draws, so the file you download looks exactly like the preview.
Save a design as a preset and it's there next visit. A preset holds only the settings — never your photos or your logo.
Questions
Are my photos uploaded?
No. There is no upload route in the code, and a test fails if the tool's code even names a network request. Stamping happens in your browser tab.
Can I watermark many photos at once?
Yes, up to twenty at a time. Photos are stamped one by one, and if one can't be read it fails with its reason while the rest finish. Download them individually or as one ZIP.
Can I use my logo as a watermark?
Yes. Pick a logo image — a PNG or SVG with a transparent background works best — and set its size and opacity like a text mark.
Does it reduce my photo's resolution?
No. The stamped photo comes out at its original size. A photo too large for the browser to draw is refused with a note, rather than shrunk without telling you.
Can someone remove the watermark?
A determined person can crop or edit one out; no watermark prevents that. Tiling the mark across the whole photo makes it much harder to remove cleanly.
Does it work with iPhone HEIC photos?
Only where the browser can read HEIC. If one fails, export it from Photos as JPEG and stamp that.