Step-by-step guide
How to Sign a PDF Online
Follow these steps to sign a PDF for free, entirely in your browser — no software install, no account required.
Four steps to a signed PDF
Open your PDF
Use your operating system's built-in PDF viewer (Preview on Mac, or any browser's PDF viewer on Windows) — no extra software needed for basic insertion.
Insert the signature image
Most PDF viewers let you insert an image directly onto the page; place your downloaded signature PNG where it belongs.
Resize, position, and save
Drag the signature to size, position it on the signature line, then save or export the completed PDF.
Mac: using Preview
Open the PDF in Preview, click the markup toolbar icon, choose the signature tool, and select a signature you've already created (or create one there). Since you already have a clean PNG from SignScribe, you can also just drag-and-drop the downloaded image straight onto the page and resize it.
Windows: using a browser PDF viewer
Chrome and Edge's built-in PDF viewers support basic annotation tools, though image insertion support varies by browser version. If your browser's viewer doesn't support inserting images directly, most free PDF editors (many run entirely client-side, similar to SignScribe) let you drag your downloaded PNG onto the page.
Common questions
Do I need Adobe Acrobat to sign a PDF?
No. Basic signing (inserting an image of your signature) works with free, built-in tools on both Mac and Windows.
Will the signature stay in place if the PDF is edited later?
A pasted image isn't cryptographically locked to the document, so for high-stakes contracts you may want a dedicated e-signature platform with an audit trail; for everyday documents, an inserted image is standard practice.