How to add fillable fields to an existing PDF
If all you have is the PDF (no Word file, no original design file), you can still make it fillable. You add form fields on top of the existing page: a text field over each blank line, a checkbox over each tick box, and so on. The page itself does not change. This guide covers which fields to use, a free way to add them, and the paid tool most people reach for.
Pick the right field for each question
| Question on the form | Field to add | Settings worth checking |
|---|---|---|
| Name, email, phone | Text field | Single line; a font size that fits the box |
| Address, notes, “anything else?” | Text field | Multi-line, with scrolling turned off if you want answers to stay visible when printed |
| Tick all that apply | Checkboxes | One checkbox per option, each with its own name |
| Pick one (Yes / No, size S/M/L) | Radio buttons | Give every button in the group the same name, so only one can be chosen |
| Fixed list of answers | Drop-down (list or combo box) | Enter the options in the order people expect |
| Date | Text or date field | Show the format in the label, for example MM/DD/YYYY |
| Signature line | Text field or signature field | A typed-name field works in every reader; drawn or digital signatures depend on the app |
Free: add fields in LibreOffice Draw
LibreOffice Draw can open a PDF, let you draw form controls over it, and export a new PDF with working fields.
- Install LibreOffice (free) and open your PDF with LibreOffice Draw.
- Check the page closely. Draw turns the PDF’s text into editable text boxes, and missing fonts can be swapped, so spacing may shift. If the result looks wrong, see the tip below.
- Turn on View → Toolbars → Form Controls and switch on Design Mode.
- Draw a Text Box, Check Box or Option Button over each place an answer belongs.
- Right-click each one, open Control Properties, and give it a unique name. Option buttons that belong together are the exception: give them all the same Name, which is how LibreOffice groups them.
- Export with File → Export As → Export as PDF, tick Create PDF form on the General tab, and save under a new name.
- Open the new file in a browser and a PDF reader, and test every field.
Tip if the layout shifts: turn each page into an image first (many PDF viewers and free tools can export a page as PNG at 150–300 dpi), insert that image into a blank Draw page sized to match, and draw your fields on top. The text is no longer selectable, but the page looks exactly like the original. This is the same approach we describe for scanned forms.
Paid: Adobe Acrobat’s Prepare a form tool
Acrobat’s Prepare a form tool (All tools → Prepare a form) analyzes a PDF and adds fields automatically; Adobe says auto-detection is on by default. It is the most common tool for this job, and it keeps the original page as it is. Form editing is part of Acrobat’s paid plans, so check Adobe’s current pricing and trial terms. Automatic detection is a starting point, not a finished form. Expect to fix field sizes, add missed checkboxes, change field types, and rename fields.
What about free online editors?
Several websites offer to add form fields in the browser. Before you use one, read its limits (page caps, watermarks, sign-up requirements) and its privacy terms. You are uploading your file to its server. That matters less for a blank template than for anything with real people’s details in it. Never upload a filled-in form to a tool you have not vetted.
Finish with a quick test
- Press Tab from the first field. Does the cursor move down the page in reading order?
- Type the longest answer you expect. Does it fit, or does the text shrink to nothing?
- Tick and untick every box. Do radio buttons in a group switch off each other?
- Save, close and reopen. Are the answers still there?
- Open it on a phone. That is where many people will fill it in.
Or have the fields added for you
Adding fields is quick on a short form and tedious on a long one, especially one with tables and dozens of tick boxes. We add text fields, checkboxes, radio buttons, date fields and a signature area, set the tab order, and test the file in Chrome and Firefox. $29 covers 1–3 pages, and $59 covers 4–10. You share a link to the blank PDF; there are no uploads.
For the big picture, read converting a PDF to a fillable form.
FAQ
Does adding fields change how my PDF looks?
It should not. Fields sit on top of the page. The exception is a tool that rebuilds the page when it opens it, such as LibreOffice Draw with some fonts; check the layout before you export.
Can I add fields in Apple Preview or Chrome?
Preview and browsers can fill in fields that already exist, and some let you type text on top of the page as an annotation, but they do not create real form fields. You need a tool such as LibreOffice Draw or Adobe Acrobat.
What is the difference between checkboxes and radio buttons?
Checkboxes let people tick any number of options. Radio buttons in the same group allow only one choice, which suits Yes/No questions.
Can you add fields that calculate totals?
Yes. Calculated fields that add up prices or quantities are a $19 add-on to either tier.
Rather not do it yourself?
Share a link to the blank PDF and we add the fields for you. $29 for 1–3 pages, $59 for 4–10, usually back within 24 hours.