Sign your PDF,
in your browser.

Draw, type or upload your signature and place it anywhere on the page. Free, private, no install.

⚡ Instant 🔒 Private 🆓 Free 📦 No install
Drop your PDF here
or click to browse
File never leaves your device — signing happens locally in your browser.
Pages—
Signatures—
↓ Download PDF

How to sign a PDF — in 3 steps

Upload a signature or stamp

Sign on white paper, take a photo, and upload it. SlimIO removes the white background so only the ink lands on the page. It works the same way for a company stamp.

Sign several pages

Use Previous and Next to move through the document and add your signature or initials wherever they are needed. To add a watermark such as COPY as well, use Watermark PDF. To send the signed file by email, compress it for email.

Sign PDF — FAQ

How do I sign a PDF for free?

Open this page, choose your PDF, and create a signature by drawing it, typing your name or uploading an image. Click Add to page, drag it into place, then click Sign & download.

Can I sign on my phone?

Yes. Draw your signature with your finger, then drag it into place on the page preview.

Can I sign more than one page?

Yes. Move between pages with Previous and Next and add your signature wherever you need it. Every placement is saved into the same PDF.

Is my PDF uploaded?

No. The PDF and your signature stay in your browser; nothing is sent to a server.

Is a signature added this way legally binding?

For many everyday documents — forms, quotes, agreements between people — a signature image is commonly accepted. It is not a certified digital signature, so for documents that legally require one, check what the recipient accepts.