How to Sign a PDF Online for Free

July 26, 2026 · By SEDI Editorial Team · 6 min read

Signing a PDF does not require a printer, a scanner, or paid software. With a browser-based tool, you can upload a PDF, add your signature, and download the signed document in under a minute. This guide walks through the process step by step.

What do I need to sign a PDF online?

The PDF signing process uses two browser-based libraries. PDF.js renders the document for preview, and pdf-lib embeds the signature into the PDF file. Both run locally on your device. The original file never reaches a server.

For mobile users, the same process works on phones and tablets. Touch input is supported for drawing signatures directly on the screen. See the mobile signing guide for details.

How to sign a PDF online in 4 steps

Step 1: Upload the PDF. Open the PDF signing tool and select your file. Drag and drop works in most tools. The PDF is read into browser memory and the first page is displayed as a preview.

Step 2: Create your signature. Two methods are available. Draw your signature on a canvas using a mouse, trackpad, or finger. Or upload an existing signature image (PNG with transparent background works best). Some tools also let you type your name and render it in a script font.

Step 3: Position the signature. Drag the signature to the correct location on the PDF page. Most tools also allow you to add text fields for dates, names, or other information.

Step 4: Download. Click the download button. The tool embeds the signature into the PDF at the correct coordinates and generates the final file. The signed PDF downloads automatically.

Can I sign a PDF without printing it?

The traditional signing workflow — print, sign with a pen, scan back to PDF — takes several minutes and requires access to a printer and scanner. An online signing tool completes the same task in seconds without hardware.

For documents that require a handwritten look, drawing the signature with a mouse or stylus produces a result that closely resembles a wet signature. The signature is embedded as a transparent PNG image, so it integrates naturally with the PDF background.

Is signing a PDF online safe?

Many online PDF services upload the file to a cloud server for processing. This means the document contents and signature data travel over the internet and are stored temporarily on a third-party server. For sensitive documents, this may not be acceptable.

Browser-based tools that use client-side JavaScript libraries keep the file on your device. The PDF is read into memory, modified locally, and downloaded directly from the browser. When you close the tab, all data is gone. The privacy policy explains the data handling in detail.

Do I need to create an account to sign a PDF online?

Paid tools like DocuSign and HelloSign require account creation and offer free tiers with limited monthly envelopes. For occasional document signing, a free browser-based tool without account requirements is a simpler option.

Account-free tools also provide better privacy since no personal information is collected or stored.

What file format should I use for a signature image?

When uploading a signature image, ensure it has a transparent background. If the image was scanned from a paper signature, use an image editor to remove the white background before uploading. The handwritten signature guide explains how to create a clean signature image.