Sign PDF Online: A Practical Step-by-Step Guide
Add a visible signature to a PDF and understand the difference between a signature image and a certificate-based digital signature.
PDFLeo provides a browser-based workflow for this common document task. Work from a copy, follow the steps below, and review the exported file before relying on it.
How to use Sign PDF
- Confirm the recipient accepts the signature method you plan to use.
- Open Sign PDF and select your document.
- Add the supported signature mark and position it in the correct place.
- Download the signed file and verify the signature is legible and on the intended page.
Best practices for reliable results
- Keep an untouched backup of the source file.
- Only process documents you have permission to use and share.
- Review every page of the output, not just the first page.
- Check text, layout, page order, links, fields and images where relevant.
- For important work, compare the output with the original before distributing it.
Limitations to know
A visible drawn or typed signature is not automatically a certificate-based digital signature and may not provide identity verification or tamper evidence. Check the recipient’s requirements before signing.
Frequently asked questions
What should I check after using Sign PDF?
Is a visible signature the same as a digital certificate signature? No. A visual mark and a cryptographic digital signature provide different assurances.
Should I delete the original file?
No. Keep the original until you have checked the output and confirmed it contains everything you need.
Related PDF help
Browse the complete PDF tool guide library or visit the PDFLeo blog for more practical document tips.
Last reviewed: October 2026. Results depend on file structure, browser support and selected options. Always verify your output.