PDF SealBox

If you've ever printed a PDF just to press a rubber stamp on it and feed it back through the scanner, you know how silly the loop feels. Marking a file as paid or approved shouldn't need a full PDF editor either. The developer of PDF SealBox says the tool came out of exactly that office habit: at work, PDFs were printed, stamped and scanned again for archiving, and the tool was built to avoid that waste. Colleagues now use it for routine archiving and add visible stamps without printing and rescanning each file.

It keeps the job to three steps. You choose a PDF, set up the stamp in a side panel, then check the preview and download a new file. The stamp can be a preset text mark such as PAID, RECEIVED, APPROVED or VOID, with REJECTED, COMPLETED, DRAFT, CONFIDENTIAL and COPY also on the list. Or you can upload your own seal as a PNG or JPG image.

You decide which pages get it, whether that's all pages, all except the first, the first or last only, or a custom range. Size, opacity and rotation are adjustable too.

The less common feature is the seam stamp. It splits one seal across the edges of the pages, so that the mark only lines up when the pages are fanned together. That's a convention on multi-page contracts in some countries, used to show no page has been swapped.

Five other tools sit beside the stamp tool. They add page numbers, turn images into a PDF, add a watermark, split a PDF and convert PDF pages to images.

A stamp here is a picture on a page, and the site is careful about that. Its tool page says the output does not cover OCR, editing PDF text, certificate-based signatures or notarization. The terms add that a visible mark is not identity verification, notarisation or a certificate-backed signature, and tell users not to create misleading, fraudulent or unauthorised stamps. The developer is just as clear: it adds visible marks, not certificate-based digital signatures, and it doesn't claim legal validity. A seal image placed with this tool looks official and proves nothing by itself.

On privacy, the policy, marked as updated August 2026, says PDF files and stamp images are processed locally in your browser when supported, and that the site does not intentionally store uploaded PDF files for the browser stamping workflow. Note the qualifier. It's a statement about the common case, not an absolute promise. Cookies may be used for analytics and for advertising such as Google AdSense where enabled.

No price is shown on the site's pages, and the tools open without an account. The about page describes an independently developed project, operated by the PDF SealBox site operator, and gives no person or company name. It also mentions a Windows desktop app, though no download page was to be found on November 10, 2026. If your office still prints files just to stamp them for the archive, try it on one routine document and see how much paper you save.