How to sign a PDF
- Drop the PDF on the page or choose it.
- Tap Signature. The first time, draw your signature with your finger, a pen or the mouse, or type your name. It is saved in this browser for next time.
- Tap the page where the signature goes. Drag to move it; use the corner to resize.
- Add Initials, the Date, Text, a Tick or a Cross the same way.
- Download the signed PDF.
Fill in PDF forms
If the PDF has form fields, they are listed under the pages so you can fill text boxes, tick boxes and choose options. “Flatten form fields” (on by default) turns your answers into ordinary text, so they cannot be changed later.
Your signature, used everywhere
Your saved signature is kept only in this browser, and is also offered in SmallKits document tools such as invoices, vouchers, delivery notes and receipts, so you can sign those with one tick.
Private by design
Contracts, leases and forms often contain personal details. Here the PDF is opened, signed and saved entirely on your device. Nothing is uploaded, and there is no account that could leak.
Is an electronic signature legally valid?
In many countries, a signature added like this is a valid “simple electronic signature” for most everyday agreements, including under the US ESIGN Act, the EU eIDAS Regulation and the UK Electronic Communications Act. Some documents, such as certain property deeds, wills and court documents, may need a handwritten, witnessed or qualified digital signature. If in doubt, ask the person you are signing for, or a lawyer.
Certified PDFs
Some PDFs carry a digital certification. Adding anything to them breaks that certification, and SmallKits warns you when it detects one.
Tips
- Zoom in with the + button to place signatures precisely on small lines.
- Use arrow keys to nudge a selected item, and Delete to remove it.
- For a typed date in your preferred format, set the date style in any document tool’s Advanced settings.
A worked example
A new tenant receives a 6-page lease as a PDF on their phone. They open Fill and sign PDF, tap Signature and draw it with a finger (it is saved for next time), then tap above the signature line on page 6 and drag the corners to fit. They tap Initials and place them at the bottom of each page, then Date beside the signature. The lease also has form fields for the tenant’s ID number and phone, which they fill in under the pages. They download the signed PDF and send it back by email, without printing or scanning anything.
Placing things precisely
- Zoom in with the + button before placing small items.
- Drag an item to move it; drag the blue corner to resize it. Signatures keep their shape.
- On a computer, select an item and use the arrow keys to nudge it; hold Shift for bigger steps.
- Press Delete, or tap the × on the item, to remove it. Undo appears for a few seconds.
Drawn or typed signature?
A drawn signature looks most like your handwritten one, and a stylus or finger on a phone gives the best results. A typed signature uses a handwriting-style font and is quicker on a computer. Both are saved only in your browser and you can change them any time.
Terms explained
- Simple electronic signature
- A signature image or typed name added to a document, valid for most everyday agreements.
- Qualified or digital signature
- A cryptographic signature backed by a certificate, required for some legal documents.
- Flatten
- Merge filled form fields into the page so they cannot be changed.
- Certified PDF
- A PDF locked by its author with a digital certificate; changes break the certification.
Your signature image stays in this browser. If you use a shared or public computer, remove it from your saved signatures when you are done.
Signed files are named after the original with “(signed)” added, so you can tell them apart at a glance.
Related free tools
- Free merge PDF tool: to add signed pages to a bigger file.
- Free split PDF tool: to send only the signed pages.
One more tip
Before you send a signed document back, open the downloaded file once to check every signature, initial and date sits where you expect.
Updated 2026-10-29