What is the most important feature of a PDF signing tool?

Privacy — how the tool handles your document. Tools that process everything in the browser without uploading are the safest choice because the file never leaves your device.

Should I use a free or paid PDF signing tool?

Free tools are sufficient for most users. Paid tools offer additional features like digital certificates, audit trails, team management, and integration with other software.

Can I sign a PDF without uploading it to a server?

Yes. Browser-based tools that use client-side JavaScript libraries can process the PDF entirely on your device. The file never reaches a server.

What to Look for in a PDF Signing Tool

July 26, 2026 · By SEDI Editorial Team · 7 min read

Choosing a PDF signing tool depends on several factors: how the tool handles your document, what signature methods it supports, whether it limits usage, and how the output looks. This guide covers the full checklist.

Privacy and data handling

The most important factor is whether the tool processes the PDF on your device or uploads it to a server. Client-side processing keeps your document private. Server-side processing may expose sensitive information.

Check the privacy policy. Tools that claim client-side processing should work offline after the initial page load. The SignPDF tool processes everything in the browser. See the privacy policy for details.

For documents containing personal information, financial data, or legal content, client-side processing is strongly recommended.

Signature methods supported

A good tool should support at least two signature methods: drawing on a canvas and uploading an image. Some tools also support typed signatures with script fonts.

Drawing on a canvas produces a handwritten look that resembles a wet signature. Uploading an image works if you already have a transparent PNG of your signature. Typed signatures are faster but look less personal.

Pen color options (black, blue, red) give flexibility for different document requirements. Some documents specify signature ink color for consistency.

Output quality and limitations

The signed PDF should be a standard PDF file that opens in any PDF reader. No watermark or branding should appear. The signature should be embedded as an image, not as a separate attachment.

Check for the following limitations before choosing a tool: daily signing limits, maximum file size, maximum number of pages, watermark on output, account requirement, and internet requirement.

The SignPDF tool has no daily limit, supports PDFs up to 50MB, does not add watermarks, requires no account, and works offline after the initial page load.

Try the free PDF signing tool

Sign your first PDF in under 30 seconds. No sign-up, no upload, no watermark.

Open the Sign Tool →