Sign PDF (Add Signature) - When to Use
Sign PDF (Add Signature) is worth opening when you already have a signature image (PNG or JPG) and need it on one page of a PDF without installing software or uploading the file. This page covers when that fits and when it does not.
When it fits
It fits best when you need a quick visual signature stamp on a single page - a letter, a form scan, or a contract page - and you already have the signature as an image. The result downloads immediately after processing, all inside the browser.
What to expect
The tool places one signature image on one chosen page at a fixed corner (bottom-right by default). It does not draw freehand on the PDF, does not fill AcroForm signature fields, and does not cryptographically certify or lock the document.
If you still need to draw the signature first, use the signature pad tool to export a PNG, then come back here. For diagonal text across every page, use the watermark tool instead.
Why trust these tools
- Ten-plus years of web tooling. The freetoolonline editorial team has shipped browser-based utilities since 2015. The goal has never changed: get you to a working output fast, without an install.
- No install, no sign-up. Open a tool and get a working output in seconds - nothing to download and no account to create. Tools that need heavy processing run it on our service, so even a low-powered machine gets the job done.
- Analytics stops at the page view. We measure which pages get visited, not what you type or upload inside a tool. There is nothing to sign in to and no profile is attached to your input.
- Open-source core components. The processing engines underneath (libheif, libde265, pdf-lib, terser, clean-css, ffmpeg.wasm, and others) are public and audit-able. We link to each one in its tool page's footer.
- Free, with or without ads. All tools are fully functional without sign-up. The Disable Ads button in the header is always available if you need a distraction-free run.