How to Fill and Sign a PDF Without Acrobat

Updated July 26, 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. Today you can complete the whole round trip digitally, for free, without installing Acrobat — but the right approach depends on what kind of PDF you’ve been handed.

Two kinds of PDF: real forms vs flat pages

Some PDFs contain genuine interactive form fields — text boxes, checkboxes, dropdowns baked into the file (the format calls this an AcroForm). Click a field and a cursor appears; 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 the 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 directly on the page preview; for flat and scanned PDFs it switches to an add-text mode where you click anywhere and type. Everything runs in your browser — the document is never uploaded, which is worth caring about for the lease agreements and HR forms this usually involves.

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 — sign with your mouse, trackpad or finger. Fast, and on a touchscreen it looks genuinely like your signature. Mouse-drawn ones look shaky; nobody minds.
• Upload an image — sign paper once, photograph it, and reuse the image forever. For a clean result, use a white background or a PNG with transparency so the signature doesn’t arrive 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?

Honest answer: usually yes, with real exceptions. Under the U.S. ESIGN Act and the EU’s eIDAS regulation, a contract generally can’t 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 is enough for 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 (advanced and qualified signatures, which use certificate-based identity), and some documents — certain deeds, wills, notarized instruments, filings that mandate a qualified signature — require those tiers or plain ink. If the counterparty specified 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 under-appreciated step: flatten the result — merge your text and signature into the page content itself rather than leaving them as editable objects. A flattened PDF renders identically in every viewer, can’t 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 a form must remain 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 — 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

Fairness requires saying: your OS may already do this well.

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

The browser route’s advantage is that it’s the same everywhere — one workflow on any machine, no app installs, and the document stays on your device from first click to final export.