How to sign a PDF
Type, draw, or upload — place & download.
Select a PDF
Read locally.
Create signature
Type, draw, or upload PNG.
Place & download
One or many pages.
What does "sign PDF online" mean?
Signing a PDF online means adding your visible signature — typed, drawn, or pasted as an image — onto a PDF document and saving the result, without printing the page, signing on paper, and scanning it back in. People reach for an online sign-PDF tool dozens of times a year: rental agreements, NDAs, school permission slips, freelance contracts, banking forms. The goal is rarely a notarised legal instrument; it is a quick "I have agreed to this" that can be sent back in minutes instead of days.
A clean signed PDF preserves the original layout exactly — your signature is overlaid on the page, not pasted into a re-rendered copy — so the document the other party receives is the document they sent, plus your mark. That makes it easy to compare, accept, and file on the receiving end.
How signing works in your browser
When you select a PDF on this page, your browser reads the file locally into memory. Nothing is uploaded. Your signature is captured in one of three ways: as text rendered onto a canvas in a script font, as a freehand drawing collected by signature_pad (smoothed and exported as a PNG), or as a PNG/JPEG you upload directly. Either way, the signature ends up as image bytes.
The PDF stamping itself runs through pdf-lib: the page tree is parsed locally, your signature image is embedded into the PDF resources, and a placement is added to each page you chose. The modified PDF is serialised in memory and returned to you as a Blob for download. None of this requires a server. Page rendering for the previews uses Mozilla's PDF.js, with WebAssembly helping with the heavier decoding paths. When you close the tab, every byte — the original, the signature, the signed result — is gone.
Common use cases
- Returning a signed rental agreement. Open the PDF, sign on the last page, save, and email it back the same hour.
- Signing freelance contracts and NDAs. Drop your signature on the signature line and an initial on every page in under a minute.
- School and medical permission slips. Sign on a phone or tablet using the draw pad, no printer needed.
- Approving expense reports. Stamp your approval signature on the cover page before forwarding to accounts.
- Acknowledging policy documents. Sign the acknowledgement page of an HR or compliance policy without installing dedicated software.
Privacy & security
Signed PDFs are often the most sensitive documents you handle — they carry your name, your handwriting, and a binding agreement. Most online signing tools upload the PDF and the signature to a server, and you have to trust that both are eventually deleted. imisspdf keeps the entire flow inside your browser: pdf-lib reads, stamps, and saves the PDF locally, and your signature image never leaves the device. See our iLovePDF privacy review for an in-depth look at how the typical upload-based model differs.
Frequently asked questions
In most jurisdictions an electronic signature — drawn, typed, or pasted as an image — counts as a valid signature when both parties agree to sign electronically. That covers everyday business under frameworks like the U.S. ESIGN Act and the EU eIDAS regulation. For high-stakes documents (real estate, certain legal filings) you may need a qualified digital certificate, which this tool does not issue. Always check the rules that apply to your contract.
Yes. The PDF, your signature image, and the signed output all stay in your browser. No upload happens at any step — pdf-lib reads the PDF locally, stamps your signature image onto the chosen pages, and saves the result back to your device. There is no account, no log, and nothing retained.
Not while it is still encrypted. You will need to unlock it first using the Unlock PDF tool (with permission to remove the password), then sign the unlocked copy. The signed file you produce here is not encrypted by default — protect it again with Protect PDF if you need to keep it locked.
Yes. After creating your signature, use the placement controls to set page, position, and size, then click "Add placement" — repeat for each page you want signed. Initials at the bottom of every page and a full signature on the last page is a typical setup.
DocuSign and Adobe Sign are enterprise e-signature platforms that include audit trails, certificate-based identity verification, and multi-party signing workflows. imisspdf is a simple in-browser stamp tool: it places your signature on a PDF and saves it locally. Use imisspdf for personal documents and informal sign-and-return cases; use a dedicated platform for regulated multi-party agreements.
Tips for best results
- Save a clean signature PNG once. Sign on a white sheet, photograph it well-lit, remove the background in any photo editor, and reuse the PNG via the Upload tab. The image path is the fastest and most consistent.
- Draw on a touch device for natural lines. The freehand pad works best with a stylus or finger on a tablet. On a mouse, the typed option usually looks better than a shaky drawing.
- Position from the bottom-right when in doubt. Most signature lines sit at the bottom of the page; the default Center/Bottom placement covers most contracts.
- Resize down, not up. Pixel-art enlargement looks terrible. Drop the size slider until the signature reads naturally — usually 20–30% of page width.
- Lock the signed PDF afterwards if needed. Use Protect PDF to add an open password to the signed document before sending it to a counterparty.
Related PDF tools
- Protect PDF — add an open password to your signed PDF.
- Unlock PDF — remove a password so a PDF can be signed.
- Edit PDF — add text, dates, or notes before signing.
- Merge PDF — combine a signed page with the rest of the contract.