Fill a PDF Form — Type Into the Fields and Save
Opens the real form fields inside a PDF and turns them into an ordinary web form you can type into — text boxes, checkboxes, radio buttons and dropdowns, with whatever was already filled in shown as it stands. Save it back as a PDF that is still editable, or flatten it so the answers become permanent. The document stays on your computer throughout.
Most people reach for this after being sent an official form and discovering that the free PDF reader on their machine will not save what they typed, or that the website offering to help wants an account and an upload. Application forms, tenancy agreements, tax declarations and consent forms are exactly the documents you should not be posting to a third-party server, and that is the difference here: the parsing and the saving both happen in the browser tab.
Two kinds of PDF that look identical
A PDF with interactive fields — an AcroForm — carries named boxes that a reader can focus and type into. A flat PDF is just a picture of a form: printed lines and labels with nothing behind them. They look the same on screen, and the quick test is to click on a line and see whether a cursor appears. This page works with the first kind. For the second, type on top of the page with the PDF editor, which places your text as an annotation.
Flatten or leave editable
Flattening merges each answer into the page content and removes the field. The result is a document whose answers cannot be changed by the next person to open it, it renders identically everywhere, and it will never lose its values to a reader that handles forms badly — which is why it is the right choice for anything you are sending on. Leave the form editable when someone else still has sections to complete, or when you expect to revise your own answers later.
When a field refuses a value
Form fields carry a font, and that font often only covers the basic Latin alphabet. Typing an accented character, a currency symbol, or non-Latin script into such a field can fail, because the character simply is not in the font the document embedded. When that happens the field is named in the message after saving rather than the whole document failing, so you can decide whether to transliterate the value or fill that box some other way.
Related: add a signature, attach supporting pages, or strip the metadata before you send the file back.
How to use Fill PDF Form
- Drop the PDF form onto the page. It is read in your browser, so nothing is uploaded.
- Every interactive field appears as a labelled input, with any value the document already contained.
- Fill in what you need. Fields the document marks as read-only are shown but locked, exactly as the author intended.
- Decide whether to flatten. Flattened answers cannot be edited afterwards, which is usually what you want before sending it on.
- Click Download Completed PDF. The original file is untouched and you get a filled copy.
Features
- Reads the real fields — text boxes, multi-line notes, checkboxes, radio groups and dropdowns, each with its own control.
- Existing values preserved — a partly completed form opens with its answers in place rather than blank.
- Optional flattening — lock the answers into the page, or keep the form live for the next person.
- Read-only fields respected — shown for context, but not editable, so you cannot accidentally alter a locked reference number.
- Honest error reporting — if a field’s font cannot encode a character, that field is named instead of the save failing silently.
- Nothing is uploaded — the form, and everything you type into it, stays on your device.
Frequently Asked Questions
Why does my PDF show no fields?
It has no interactive form inside it. Scanned paper and flat designs are pictures of a form, not a form. Use the PDF editor to type on top of the page instead.
Should I flatten the form?
Flatten it if you are sending the completed document to someone else: the answers become part of the page, cannot be edited, and will display the same in every reader. Leave it unflattened if the form still needs input from another person or you expect to change your own answers.
Is my data sent anywhere?
No. The PDF is parsed with pdf-lib inside this tab and the filled copy is generated locally. Nothing you type is transmitted, which is the point when the form asks for a national insurance number or a bank account.
One of my answers did not save. Why?
Almost always because the character is missing from the font the form embeds — accented letters, curly quotes, currency symbols and non-Latin scripts are the usual culprits. The message after saving names the fields that were skipped so you can adjust them.
Can I fill a signature field?
Digital signature fields are cryptographic and are not filled here. To place a drawn or typed signature image on the page, use Sign PDF.
Does it work on a locked or password-protected form?
Not while it is encrypted. Unlock it first with Unlock PDF using the password, then fill the unlocked copy.
Will the form look the same after I save it?
Yes. Only the field values change; the page content, fonts and layout are left exactly as they were. Flattening changes how the values are stored, not how the page is drawn.