How to Add a Watermark on Mac with Preview
Preview, the image and PDF viewer built into every Mac, doesn’t have a watermark function. Its Markup tools let you add text and paste a logo onto images and PDF pages, which works as a basic watermark. Here’s how — and what to watch out for.
Quick answer
Open the file in Preview, click the Markup button (pen icon) and choose the Text tool (T). Type your watermark, set font and color in the Text Style menu, drag it into position, and save with File → Export. For a logo, copy it and paste it onto the image, then resize.
How to add a text watermark in Preview
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Open your file in Preview
Double-click the image or PDF (Preview is the default app) or right-click → Open With → Preview.
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Show the Markup toolbar
Click the Markup button (a pen tip in a circle) or choose View → Show Markup Toolbar.
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Add text
Click the Text tool (T in a box). A text box appears; type your watermark.
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Style the text
Click the Text Style button (A) to choose font, size and color. In the macOS color picker (Show Colors), the Opacity slider lets you make the color semi-transparent.
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Position it
Drag the text box where you want the watermark. Preview doesn’t rotate text boxes, so it stays horizontal.
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Export a copy
Choose File → Export to save a new file and keep the original intact. For PDFs, repeat the text on each page — Preview can’t apply it to all pages at once.
How to add a logo watermark in Preview
- Open your logo in Preview, press Cmd + A and Cmd + C to copy it.
- Open the photo and press Cmd + V. The logo is pasted as a movable object.
- Resize it with the corner handles and drag it into place, then export.
Preview has no opacity control for pasted images, so the logo appears fully opaque unless the PNG itself is semi-transparent.
Why Preview isn’t ideal for watermarks
- No rotation for text — no diagonal watermarks.
- No batch processing, and in PDFs each page has to be done by hand.
- PDF annotations can be deleted: text added with Markup to a PDF is an annotation that others can select and remove.
- No opacity control for logos.
Mac users can get a proper watermark in the browser instead: WatermarkOn works in Safari and Chrome, applies text or logos at any angle and opacity, handles all PDF pages at once, and never uploads your files.
The faster way: watermark without Preview
Preview gets the job done, but it was not built for watermarking. If you just need your name or logo on your files, WatermarkOn does it in your browser in under a minute:
- Open WatermarkOn and drop in your images or PDFs (as many as you want).
- Type your text or upload your logo (transparent PNG works best).
- Pick a position — a preset like centred or bottom-right, an exact percentage, or a pixel distance from any corner — then set opacity and rotation.
- Click “Add watermark” and download each file or everything as a ZIP.
Preview vs WatermarkOn
| Preview | WatermarkOn | |
|---|---|---|
| Time for 20 files | 30+ min (page by page) | About 1 minute |
| Batch processing | No | Yes, unlimited files at once |
| Watermark PDFs | Page by page, as removable annotations | Yes, all pages or a page range |
| Precise positioning | Manual drag, no rotation | Presets, % or pixels from any corner |
| Install / account | Built into macOS | Nothing, works in any browser |
| Price | Free | Free |