Filling out a PDF form without Acrobat is completely doable — most tools that can view a PDF can also fill in interactive form fields, and for forms without interactive fields there are overlay methods that work just as well. You almost certainly already have what you need.
Interactive Forms: Most Viewers Handle These Already
If the PDF has interactive form fields — text boxes, checkboxes, radio buttons, dropdown menus that respond when you click them — you can fill them in Adobe Reader (free), Preview on Mac, Microsoft Edge on Windows, or any modern browser. Click into a text field and type. Click a checkbox to check it. Select from a dropdown. These basic interactions work in virtually all PDF viewers without Acrobat Pro.
After filling the form, save it. In Preview: File → Export as PDF saves the filled version. In Edge: the browser will prompt you to save when you close. In Chrome: go to Print → Save as PDF to capture the filled state. Some viewers save automatically; others require an explicit save step — confirm the filled values are in the saved file before closing.
Non-Interactive Forms: Adding Text as Overlays
Many PDF forms aren't interactive — they look like forms visually but have no clickable fields, just blank lines or boxes printed on the page. For these, you add text as overlays positioned over the form fields. WukongPDF's PDF Editor handles this: upload the form, use the text tool to click on a blank area and type the response, position and resize the text to fit the field, and repeat for each field. Download the filled form when done.
Preview on Mac works for this too — open the Markup toolbar, select the text tool, click where you want to type, and add the text. The font and size can be adjusted to match the form's existing text style, which makes the filled version look more natural. The text sits as an annotation layer over the form image, appearing in the right place when viewed or printed.
Signing Where Required
Most forms that need to be filled out also need a signature. The same tools handle both: fill the text fields first, then add a signature image to the signature line using the signature tool in Preview, WukongPDF's Sign PDF tool, or Adobe Reader's Fill & Sign feature. Reader's Fill & Sign function is particularly convenient because it combines form filling and signature in one interface — you can handle both steps in the free app without switching tools.
When a Form Refuses to Save Filled Fields
Some PDFs are locked in ways that prevent saving filled form data — the creator restricted the PDF to disallow saving with data, intending that the form be printed and submitted on paper. When you fill such a form and try to save, the viewer may warn that the data won't be saved, or the saved file may appear blank when reopened.
The workaround: print the filled form to PDF (using Save as PDF on Mac or Microsoft Print to PDF on Windows) rather than saving it normally. The print-to-PDF process creates a new PDF from the rendered page — a flat image of the filled form — that preserves the visible content regardless of the original form's restrictions. The result is a completed form you can save, share, and archive without the original form's restrictions applying.
Filling Forms on Mobile
On iPhone, the Files app handles interactive form fields directly — tap a field and the keyboard appears. For non-interactive forms, the Markup tool in Files works for adding text overlays, though positioning text precisely on a phone screen is fiddly. Adobe Reader on iOS handles both interactive and non-interactive forms better than the built-in tools and is worth installing for anyone who regularly fills forms on a phone. On Android, Adobe Reader is similarly the most capable free option for mobile form filling.