How to Fill and Sign a PDF Without Acrobat

By Sibtain Ali · Published July 26, 2026 · Updated August 31, 2026

Someone emails you a PDF: fill this in, sign it, send it back. Printing it, scrawling on it and photographing the result is the workflow of 2009. You can do the whole round trip digitally now, for free, without installing Acrobat. The right approach depends on what kind of PDF you have been handed.

Two kinds of PDF: real forms vs flat pages

Some PDFs contain genuine interactive form fields, with text boxes, checkboxes and dropdowns baked into the file. The format calls this an AcroForm. Click a field and a cursor appears, and your text is stored as structured data.

Many more PDFs are flat: a scan, or a print-to-PDF where the “fields” are just pictures of boxes. Nothing is clickable, so a tool has to let you place text on top of the page at the right spot.

A good filler handles both. Our PDF Form Filler detects real AcroForm fields and lets you type into them on the page preview, and for flat or scanned documents it switches to an add-text mode where you click anywhere and type. It runs in the browser rather than handing your document to a processing server, which is worth something given that this task usually involves lease agreements and HR forms.

Adding your signature: draw or upload

There are two practical ways to get a signature onto the page, and Sign PDF supports both.

• Draw it with your mouse, trackpad or finger. Fast, and on a touchscreen it looks genuinely like your signature. Mouse-drawn ones come out shaky and nobody minds.
• Upload an image instead: sign paper once, photograph it, and reuse the file forever. Use a white background or a PNG with transparency so the signature doesn’t arrive sitting inside a visible gray box.

Either way you then drag the signature into position, resize it to sit on the line, and export.

Is a drawn signature legally valid?

Usually yes, with real exceptions. Under the U.S. ESIGN Act and the EU’s eIDAS regulation, a contract generally cannot be denied validity merely because the signature is electronic. An image of your signature, placed with intent to sign, counts as a simple electronic signature, and that covers the everyday run of contracts, consent forms, leases and offer letters.

What it does not give you is cryptographic proof of who signed. eIDAS defines stronger tiers, the advanced and qualified signatures that use certificate-based identity, and certain documents require them or plain ink: some deeds, wills, notarized instruments and filings that mandate a qualified signature. If the counterparty asked for DocuSign-style audit trails or a qualified signature, use what they asked for. For “sign this form and email it back,” a placed signature image is the accepted norm.

Flatten before you send

One step people skip: flatten the result, merging your text and signature into the page content instead of leaving them as editable objects. A flattened PDF renders identically in every viewer, cannot have your entries silently shifted or edited by the next person’s software, and prints exactly as you saw it. Both tools above bake your additions into the exported file, so what you download is what the recipient sees. If the form has to stay editable for someone downstream, keep an unflattened copy for them and send the flattened one for the record.

Step by step: the browser workflow

1. Open the PDF Form Filler and choose your file.
2. If fields light up, type straight into them. Otherwise click anywhere on the page to add text where the blanks are.
3. Check dates, checkboxes and page 2, which are the fields everyone forgets.
4. Open the result in Sign PDF, draw or upload your signature, and drag it onto the signature line.
5. Export, skim the final PDF once, and send it.

The built-in alternatives

Your operating system may already handle this well.

• On macOS, the Preview Markup toolbar fills text and stores signatures, drawn on the trackpad or captured by holding a signed sheet of paper up to the camera. Excellent, and Mac-only.
• On iOS, the Markup pencil in Mail or Files lets you fill and sign attachments directly.
• On Android, Google Drive’s PDF viewer has gained fill-and-sign abilities, and the free Adobe Fill & Sign app covers the rest.
• Windows is the weak spot. Edge can add drawn ink but is clumsy with typed form text, which is precisely where a browser tool earns its keep.

What the browser route buys you is sameness: one workflow on any machine, no app installs, and a document that is processed in the page from first click to final export.