How-to PDF

How to fill in and sign a PDF form without printing it

Fill in a PDF form and sign it on screen, with no printer or scanner. Preview on a Mac, the browser's own PDF viewer, one pdftk command for fillable fields, and what a drawn signature is and isn't.

BrowserBasedTools 19 Oct 2026 2 min read Either way

Two kinds of PDF form land in your inbox. A fillable form has real fields: click one and a cursor appears. A flat form is a printed page saved as a PDF, or a scan, with lines to write on and nothing to click. Which one you have decides the best way to fill it, so check that first.

Fill and Sign PDF with a volunteer registration form open: the icon toolbar above the page, the name Jane Example typed on the Full name line, a checkmark in the safety box, a drawn signature on the Signature line, the date on the Date line, and the Save signed PDF button — A flat form filled in and signed in the browser, with nothing printed or uploaded.

The direct wayPreviewmacOS

On a Mac, Preview does both kinds. Open the PDF and:

Fillable form: click a field and type.
Flat form: click Show Form Filling Toolbar, then the Text Box Tool, and put a text box where you need one.
Signature: click Show Markup Toolbar, then Sign. Create a signature once (with the Trackpad, by holding a signature on paper up to the Camera, or on a nearby iPhone or iPad), then click it to drop it on the page and drag the handles to size it.

Save with File › Save, or File › Export as PDF… to keep the original. Apple's steps are in the Preview User Guide.

Fillable or flat?

Click where the answer goes. If a text cursor appears, or the box highlights, it is a fillable form: type into the fields, in Preview on a Mac or in the PDF viewer built into Chrome, Edge or Firefox, and save. Values typed into fields stay editable and any form software can read them.

From a terminal, pdftk lists the fields. A fillable form prints a block per field (two of our test form's six are shown here):

pdftk form.pdf dump_data_fields

Questions people ask

Is a drawn signature legally binding?

For most everyday paperwork (a consent form, a volunteer form, a lease renewal) a signature drawn or pasted onto the PDF is what the other side expects, and it is usually accepted. It proves nothing on its own, though: it is a picture, and anyone can copy it. If the sender asks for a digital signature, or for a particular e-signature service, a drawn one is not that. Ask them.

What happens to a fillable field I type over?

It becomes part of the page. When you save, Fill and Sign PDF draws each field that your text, tick or signature overlaps into the page, with the value it holds, and puts your item on top, so everything shows in the saved file. Fields you didn't touch stay fillable. A field you typed over can't be edited as a field any more, and form software won't find a value in it, so if the form is read by software, type into the fields themselves in Preview or your browser's PDF viewer.

Can the person I send it to change what I typed?

Anything in a PDF can be changed by someone with a PDF editor. Text in a fillable field stays editable by design. Text and signatures added with Fill and Sign PDF become part of the page, so there is no field to retype, but they can still be covered or removed. Only a digital signature shows that a file was changed after signing.

The PDF is already signed by the other party. Can I add my signature?

Not with a tool that rewrites the file, ours included. A digital signature covers the exact bytes of the file, and when we saved a signed test PDF through Fill and Sign PDF, its signature no longer validated. Fill and Sign PDF warns you as soon as you open a digitally signed PDF. Ask the sender how they want you to sign: usually that means their e-signature service, or a reader that adds your changes as an incremental update.

Can I do this on a phone?

Yes. Fill and Sign PDF works in a phone browser: tap where the text goes and type, and draw your signature with a finger. The finished file downloads to the phone, ready to attach to an email.

Tools in this guide

Everything runs on your device

Fill and Sign PDF

All guides First published 18 Oct 2026