Fill PDF Forms Online — Free & Private
Fill in PDF form fields, checkboxes, and dropdowns in your browser, with the option to lock the form when you're done.
Open a PDF form and complete every field right in your browser — text boxes, checkboxes, and choice lists. When you're finished, you can lock the form so the answers can't be changed.
How to fill a PDF form (3 steps)
- Open the PDF form. All of its fields are listed automatically.
- Type your answers, tick checkboxes, and pick options as needed.
- Choose whether to lock the form, then save.
Which files it works with
This tool works with PDFs that have form fields built into the file (AcroForm), such as forms an organization has prepared for filling in on a computer. It reads every field and shows them as a list for you to complete:
- Text fields — type your answer. Thai text is supported too: the font is embedded automatically so all characters display correctly.
- Checkboxes — checked or unchecked.
- Choice fields — pick from the options the form defines.
If the file has no form fields — a scan, for example, or a form made of plain lines — the tool will suggest using Edit PDF to place text anywhere on the page instead, or turning it into a fillable form with Make Fillable Form.
The "lock form after filling" option
Tick this when you're done and don't want anyone to change the answers. Your entries are converted into regular page content and the form fields are removed, which suits documents you're actually submitting. If you might need to edit later, leave it unticked — or keep an unlocked copy as well.
Tips
- After filling, open the file in another viewer to double-check. Some forms define small fields, and long text may be shrunk to fit.
- Need to sign as well? Take the file straight to Sign PDF.
FAQ
Can I fill forms in Thai?
Yes. When you type Thai text, the Thai font is embedded automatically.
What if the file has no form fields?
Use the Edit PDF tool to type text and place it anywhere on the page.
What does locking the form do?
It makes the filled-in fields uneditable, which suits the final version you submit.
Why does my text disappear when I open the file on my phone?
Some viewer apps don't display values stored in form fields. Try ticking "lock form after filling": the text becomes part of the page and shows up in every program.
How do I fill date or number fields?
Type them as text in the format the form asks for. The tool does not calculate or validate formats.
Can I edit my answers later?
Yes, as long as you didn't lock the form. Open the filled file in this tool again and your previous entries will be there to edit.
📖 Full guide: Fill and sign PDF documents online