Fill a PDF form

How to fill a PDF form here

1. Open the form. Tap Choose a PDF or drop the file on the box. The page reads the form's fields: text boxes, multi-line boxes, checkboxes, radio buttons, dropdowns and option lists.
2. Fill it in. On the page puts a real input over each box, scaled with the page, so you type where you see it; Tab moves through the fields page by page in the order the form defines. As a list shows every field with its label, page and type, which is easier on a phone. Both views are the same answers.
3. Save or flatten. Save gives yourform-filled.pdf with the boxes still editable. Flatten gives yourform-flattened.pdf with the answers printed on the page and no fields left.

What it cannot do

• XFA forms. Some government and tax forms are built as XFA, Adobe's XML form format. No browser library fills them; this page says so instead of saving a broken copy. Adobe Acrobat Reader still opens them.
• Password-protected files. A PDF that needs a password to open, or that is encrypted against changes, cannot be opened here. If you know the open password, Unlock PDF saves a copy without it.
• Calculated fields do not recalculate. Totals, dates and other boxes driven by the form's JavaScript keep whatever value they had; type the result yourself or let Acrobat recompute it.
• It does not sign. A signature field is listed but not filled. Add a drawn or typed signature with Sign PDF after you save.
• Latin letters only. Answers are drawn with the standard Helvetica font, which covers English and most Western European letters (é, ø, ß) but not Greek, Cyrillic, Arabic or Chinese. The page tells you instead of writing an unreadable file.
• Boxes without fields. If the PDF is a scan or a printout saved as PDF, the boxes are only drawn lines; there is nothing to fill, and Sign PDF lets you type on top instead.

What happens to the file

A fillable PDF stores each box as an AcroForm field: a name, a type, a value and one or more widgets, the rectangles on the page where the box is drawn. This page reads them with pdf-lib, draws the pages with PDF.js (the viewer inside Firefox) and lays an input over each widget rectangle. Both libraries are pinned copies served from this page and load only when you open a file.

If a text field has a MaxLen (common for ID numbers, postcodes and comb boxes with one letter per square), the input stops at that length and the value is cut to it again before writing, because a PDF reader would refuse or truncate a longer value anyway. A 20-character name box keeps the first 20 characters.

On Save, only the fields you changed get new values and freshly drawn appearances, so the rest of the form, its pages, fonts and links are copied as they were. On Flatten, every field's appearance is drawn into the page content and the fields are removed; the text stays selectable and searchable in the result.

Questions

What is the difference between Save and Flatten?

Save keeps the boxes as boxes, so anyone can still correct an answer in a PDF reader. Flatten turns the answers into ordinary page text and removes the boxes. Send a flattened copy when you want the answers fixed; keep a saved copy for yourself in case you need to change something.

Why does it say my form is an XFA form?

XFA forms keep the form as XML inside the PDF instead of as normal fields. Browsers, Apple Preview and the libraries here cannot fill them, and Adobe has deprecated the format. Open the form in Adobe Acrobat Reader, or ask the issuer for a standard fillable PDF.

Is my PDF uploaded anywhere?

No. The file and your answers stay in this page's memory. The page fetches only its own code from this site and sends an anonymous page-view count with a fixed event name (open, save or flatten); no request contains the file, its name or anything you typed.

How do I fill a PDF form on a phone?

Tap Choose a PDF and pick the form from Files or Drive. On a narrow screen the fields open as a list with labels and page numbers; switch to On the page to check where each answer lands. Then tap Save or Flatten.