Fill a PDF form
Open a PDF that has form fields, fill them in, and flatten it so the answers become part of the page and cannot be edited back out.
The forms people actually fill are tax returns, visa applications, medical intake sheets and rental agreements — the exact documents you should not hand to a free web service in exchange for an email address. This one opens the file on your device, lists every field it finds, and gives it back. Flattening is the part the paid tools charge for; here it is a second button.
Every field is outlined on the page. Click one to jump to its row, or click a row to find it here.
Questions people ask
Is my PDF uploaded when I fill it in?
No. The file is read into memory, drawn to a canvas and rewritten entirely inside your browser. The uploads counter in the top bar stays at 0, and you can watch the same thing in your dev-tools Network tab. This matters more here than almost anywhere else, because the forms people fill are tax returns, visa applications, medical intake sheets and rental agreements.
What does flattening actually do?
Flattening paints your answers onto the page and then deletes the form itself. The text looks identical, but it is no longer a field, so nobody who receives the file can click into it and change what you wrote — or accidentally clear it. Save filled keeps the fields as fields, which is what you want if you still need to edit it later.
Do I have to pay to flatten, or will there be a watermark?
Neither. PDFescape, Smallpdf and most of the others put flattening behind a subscription, or stamp their logo across your document to advertise it. This has no account, no page limit, no watermark and no paid tier, because there is no server to pay for.
It says my PDF has no form fields — what now?
Then the document is flat: the boxes and ruled lines are drawn on the page, not real fields, which is normal for anything that was scanned or exported to print. There is nothing to fill in, so the tool refuses rather than handing you back an unchanged file. Use Sign a PDF instead — it stamps text and signatures on top of a flat page.
Why are the field names gibberish like f1_07[0]?
Because whoever built the form never gave the fields human names, which is depressingly common on government PDFs. That is what the highlight is for: click a name in the list and its box is outlined on the page, or click a box on the page and the list jumps to the right row.
How this works & why it’s private
Your PDF is read with the File API, drawn to a <canvas> with pdf.js, and its AcroForm fields are read and rewritten with pdf-lib. All three are plain JavaScript files served from this domain and run on your device. There is no server step anywhere in that chain, so there is no copy of your tax return in someone's bucket.
Two limits worth knowing before you rely on it. XFA forms — the Adobe LiveCycle kind, still handed out by some government departments — keep their fields in an XML layer rather than the standard AcroForm one; no browser can fill those, and this tool says so rather than pretending. Encrypted PDFs cannot be read at all without the password, so open one in your usual reader first and save an unprotected copy.
There is a smaller one too. A PDF form draws its own text using a font the file carries, and some forms carry only a Western one. If you type a character that font cannot write — an Indic or CJK character, most often — the tool names the field and the character instead of silently dropping your answer or throwing an error at you.