To add an image to a PDF online for free, open the file in the Add Image to PDF tool, choose a PNG or JPG image such as a company logo, pick one of nine positions, set the width as a percentage of the page width and the opacity, choose which pages receive the stamp, and download the stamped copy. The image is embedded once and drawn onto each chosen page at the position you picked, computed from that page's own width and height, so mixed page sizes stamp proportionally. Nothing is uploaded: the PDF and the image are combined in your browser, and your original file is never changed.
When Stamping an Image Is the Right Job
A logo on every page is the quietest form of branding a document can carry. Invoices, quotations, reports and proof galleries all look more finished when the sender's mark sits in the same corner of every page, at the same size and the same fade, rather than appearing once on a cover sheet and vanishing for the rest of the document. Readers who print a single middle page still see whose document they are holding, and a file forwarded without its cover still carries its origin with it.
The same tool covers a second, very different job: a faint image used as a watermark. Drop the opacity to around half, choose a central position, and a photograph, a draft mark or a sample graphic sits behind the text without hiding it. Photographers use this for proof galleries, designers for draft issues, and small businesses for sample documents that should not be mistaken for final copies. The difference between a logo and a watermark here is only a matter of settings: solid and small in a corner for branding, large and faded in the centre for marking.
Stamping is not editing. It adds a layer on top of existing pages; it does not move, rewrite or replace the text underneath. That distinction matters when you choose a tool: if you need to place different images on different pages, or position an image by clicking exactly where it should sit on one page, the Edit PDF studio is the better fit, because it works page by page with click positioning. When the job is one image, repeated consistently across a whole document or a defined page scope, this tool finishes it in a single pass.
Using the Add Image to PDF Tool, Step by Step
- Choose the PDF, then the image. Pick the PDF on your device or drop it onto the panel, then choose the PNG or JPG to stamp. Either order works; the tool is ready when both are in. A PNG with transparency keeps its see-through areas see-through, while a JPG has no transparency, so its background stamps as a solid rectangle.
- Pick one of the nine positions. Corners, edges and centre are all offered. A corner placement suits a logo; a centre placement suits a watermark. For corner placements, set the margin from the page edges so the stamp never crowds the trim.
- Set the width and the opacity. Width is a percentage of the page width, and the height follows the image's own proportions, so nothing is stretched. Use 100% opacity for a solid logo and a lower value for a watermark effect. Opacity is written as a real PDF transparency value.
- Choose the page scope and download. Stamp every page, the first page only, or the last page only, then click Add image and download. Open the result and check the first, a middle and the last page before you send it on.
Tip: Shrink a large photo before you stamp it. The image is embedded at its original resolution, so a 4 MB photo adds a 4 MB payload to the PDF even when it displays small on the page, because the on-page display size is set by the width slider regardless. A quick resize to a sensible width keeps the stamped file lean.
Logo Stamp, Watermark, or Full Edit: Which Job Is Which
Image tools overlap, and picking the wrong one costs a second pass. The table separates the jobs so you start with the right tool.
| Your job | Tool to use | What happens | Watch out for |
|---|---|---|---|
| Same logo on many pages | Add Image to PDF | One image, nine positions, page scope | One image per run only |
| Text watermark, tiled or centred | Watermark PDF | Text stamped with watermark controls | Text only, not an image file |
| Different images, exact click placement | Edit PDF | Text and images placed page by page | Slower for whole-document repeats |
| Signature graphic on one page | Sign PDF | Drawn or uploaded signature stamped | Built for signatures, not logos |
| Page numbers on every page | Add Page Numbers to PDF | Numbers in your format and position | Numbers only, not images |
Worked Example: A 12-Page Proof Gallery, Logoed in One Pass
A photographer delivers a 12-page proof gallery to a client. Her logo is stamped at 18% width, 55% opacity, bottom-right of every page, exactly as the live tool page describes. One pass stamps the whole set consistently: the same size, the same corner, the same fade on all twelve pages, rather than twelve separate placements that would drift from page to page. Before sending, she checks page 1, page 6 and page 12, because a consistent stamp should look identical in all three spots. The chart below shows the four checkpoints she uses: the stamp width of 18%, the opacity of 55%, the 12 pages stamped, and the single pass it took. If any page showed a different size or corner, she would know the run had not applied uniformly, but with one image and one set of settings, that check is a formality that takes seconds.
| Checkpoint | Setting | Pages checked | Result |
|---|---|---|---|
| Logo width | 18% of page width | Pages 1, 6, 12 | Same size on all three |
| Opacity | 55% | Pages 1, 6, 12 | Same fade, text readable |
| Position | Bottom-right | Pages 1, 6, 12 | Same corner on all three |
| Page scope | Every page | All 12 pages | Stamp present throughout |
Add Image to PDF example — hover or tap each bar for details.
Getting the Best Result
Choose the image file with the same care you would choose the logo itself. A crisp PNG with a transparent background stamps cleanly on any page colour, while a JPG with a white box around the logo will carry that white box onto every page, including pages with coloured backgrounds. If your logo file has a solid background you cannot remove, test it on one page first: stamp a copy, open it, and look at the edges before you commit to stamping the whole document.
Match the width to the page, not to your screen. A logo that looks modest on a large monitor can dominate an A4 page, and one that looks bold on a phone can vanish on paper. As a starting point, a corner logo between 15% and 25% of the page width reads as branding without competing with the content, while a centre watermark between 40% and 60% width at reduced opacity sits behind the text. Print one page, or view it at full page size, before you judge.
Keep the stamped file and the original apart, and name them so the difference is obvious. The tool never changes your original, so you always have a clean copy to return to, but only if you do not overwrite it with the stamped download. A name such as gallery-proof-logoed.pdf next to gallery-proof-clean.pdf makes the pair self-explanatory months later, when neither file's history is fresh in your mind.
Common Mistakes
1. Stamping a JPG logo with a white background. On white pages it looks fine, which is why the problem only appears later, on a coloured or shaded page where the white rectangle shows. Use a transparent PNG for logos whenever you can.
2. Setting the width from a thumbnail preview. Previews shrink the page, so proportions mislead. Judge the stamp at full page size or on a printed page, not in a small preview pane.
3. Using full opacity for a centre watermark. A solid centre image hides the text beneath it. Centre placements need reduced opacity so the document stays readable; solid stamps belong in corners.
4. Forgetting the margin on corner placements. A stamp hard against the trim can be clipped by printers. A modest margin keeps it safely inside the printable area on every page.
5. Stamping before the document is final. If the text changes after stamping, you must stamp again, because the stamp is a layer added to finished pages. Finish the content first, then stamp as the last step.
Key takeaway: Add Image to PDF stamps one PNG or JPG onto PDF pages in nine positions, at a width you set as a percentage of the page width and an opacity that turns a logo into a watermark when lowered, on every page, the first page or the last — all in your browser, with the original untouched.
Frequently Asked Questions
How do I add an image to a PDF online for free?
Open the PDF in the Add Image to PDF tool, choose a PNG or JPG image, pick one of nine positions, set the width and opacity, choose the page scope, and download the stamped copy.
Can I stamp a transparent logo?
Yes — upload a PNG with transparency and the see-through areas stay see-through on the page. JPG has no transparency, so its background stamps as a solid rectangle.
How is this different from Watermark PDF?
Watermark PDF stamps text, tiled or centred, with watermark-style controls. This tool stamps an image file — logos, photos, signature graphics — with page-scope and margin controls.
Can I stamp different images on different pages?
One image per run, on every page, the first or the last. For a one-off placement on a specific page with click positioning, use Edit PDF.
Why did my stamped PDF get bigger?
The image is embedded at its original resolution. A 4 MB photo stamps a 4 MB payload into the file; shrinking the photo first keeps the PDF lean, and the on-page display size is set by the width slider regardless.
Will stamping change my PDF text or quality?
No. Nothing is re-rendered: the underlying pages keep their text, vectors and quality, and the image is drawn onto each chosen page as an added layer.
Is my PDF or image uploaded?
No — the PDF and the image are combined in your browser and the result downloads directly.
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For the surrounding document workflow, pair stamping with Watermark PDF for text watermarks and Sign PDF for signature graphics. More step-by-step tool guides live on Asad Webs blog.
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