Windows has had PDF signing baked into Edge for years and most users don't know. For a one-off sign, you don't even need a separate tool. For anything else, the browser has you covered.
Signing in Edge
Open the PDF in Edge. In the toolbar, click Draw. Pick black, pick a thickness. Sign with mouse, trackpad, finger (if touchscreen), or pen (Surface). Save. The signature is now part of the PDF.
Fast and built-in. Good for quick signs. Limitations: can't save signature for reuse, can't position with precision, no separate signature step.
Signing in Flint
Flint's signer handles the limitations. Draw once, place anywhere, save for the session, drop on multiple pages. Works in Edge, Chrome, Firefox. The flow: open Flint, upload PDF, click Sign, draw signature, place on document, download.
For contracts with initials on every page plus a signature at the end, Flint is faster than Edge's per-page drawing.
Surface pen workflow
Surface Pro with a Surface Pen is one of the best Windows signing setups. Pen pressure comes through both in Edge's draw tool and Flint's signature pad. Result looks like a real signature on real paper — natural line variation, no jagged edges.
After signing
Saved PDF can go anywhere. Outlook attachment, OneDrive, Teams chat, anywhere on Windows. If it needs further changes — say, the recipient asked you to also edit a field — edit text in Flint and save again.
FAQ
Is a mouse-drawn signature legally valid?
Yes, in most jurisdictions — eIDAS in UK/EU, ESIGN in US. A reproducible mark with clear intent generally counts. Surface pen signatures look more like real signatures; mouse-drawn are functional but less polished.
Can I use a Wacom tablet?
Yes. Any pen-input device that Windows recognises works in Edge's draw and Flint's signature pad. Wacom tablets give excellent line quality.
What if the PDF needs signing in a specific field?
Flint lets you position the signature anywhere by dragging. Edge's draw works similarly. For PDFs with declared signature fields (rare in everyday use), specialised e-sign services handle field detection automatically.
For one-off signs, Edge. For everything else, Flint. Both free, both on Windows.