How to fill a PDF form

How to fill the form, step by step

Filling a PDF form takes under a minute:

1. Open the Fill forms tool.
2. Drag the PDF with the form into the window, or click to pick it.
3. Type one field=value pair per line, with the exact field name from the source PDF.
4. Download the filled document you get at the end.

Nothing to install, no account and no upload wait. The whole job happens on your computer, start to finish.

Tips for filling forms

• Field names count to the letter. Upper case, lower case, spaces and accents are all part of the name. If it does not match, the error message shows the exact name it did not recognise. A PDF reader with a forms panel, like Adobe Acrobat Reader, also shows field names when you hover over them.
• To check a checkbox. Use 1 (or sim, true, x, on) to check it, and 0 (or an equivalent empty value) to uncheck it.
• Dropdowns and option groups only accept the PDF's own values. A value outside the list is refused rather than accepted blindly, so the document never ends up with an option the form's interface never shows.
• Digital signatures and buttons cannot be filled with text. They are AcroForm field types that do not take text; the tool refuses them rather than pretending it wrote something.
• Use flatten to close the document. If you tick the flatten option, the value becomes part of the page drawing and the field can no longer be edited afterwards.

It only works with PDFs that have real AcroForm fields

The tool writes into form fields the PDF already has: text boxes, checkboxes, dropdowns and radio groups drawn as actual fields. A "drawn" form, lines and boxes that are just drawing, or plain text pretending to be a field, common in scans, has no AcroForm at all, and the tool refuses rather than pretending it filled something. There is no box detection or OCR here.

If the document has digital signatures or buttons, those fields stay untouched: they are AcroForm types that cannot be filled with text. If what you need is to write a line at an exact spot on the pages, use the Add text tool; to sign, use Sign PDF. And the PDF properties tool shows what the document holds, without changing it.

The field=value format, line by line

Each line names one field: the exact field name in the PDF, an equals sign and the value, for example, name=Jane Smith. One field per line, with no practical limit on the number of lines: filling thirty fields at once is perfectly normal.

There is no preview list of fields inside the tool today: write the name you believe is right and, if it does not match, the error message states which name it did not recognise. Check upper case, lower case, spaces and accents, all of which count toward the field name.

Is filling forms free? What are the limits?

This tool is part of the Premium subscription, EUR 1.99 a month, which removes the limits on every tool and adds OCR. Sign PDF opens on the free plan, with one signature a day.

Sources

• BestPDFInTheWorld, Preencher formulários
• Adobe, PDF forms (AcroForm)