Fill in a fillable PDF form entirely in your browser — upload a PDF with an AcroForm, and the tool automatically detects its text fields, checkboxes, radio buttons, and dropdowns so you can fill them in and download the completed PDF. No upload, powered by pdf-lib.
Drag and drop a fillable PDF form here, or click below to browse.
When you upload a PDF, this tool opens it with pdf-lib and asks for its AcroForm — the standard PDF structure that holds every interactive field definition, including each field's name, type, and (for radio buttons and dropdowns) its list of valid options. The tool then walks through every field it finds and checks its underlying type against four supported categories: text fields, checkboxes, radio button groups, and dropdowns, generating the right kind of input control for each one automatically. There's no manual setup or field mapping required — the generated form always matches exactly what the original PDF's creator built.
Text fields accept free-form typed input and optionally enforce a maximum character length set by the original form. Checkboxes represent a simple on/off choice, like agreeing to terms or opting into a category. Radio button groups let you pick exactly one option from a fixed set (like a Yes/No/Not Applicable question), where the PDF itself defines which value each option represents. Dropdowns work similarly to radio groups but present their options as a select menu rather than a row of buttons, typically used when a field has many possible options (like choosing a state or country).
Once you click Fill PDF, the tool reloads the original file and, for each field, calls pdf-lib's field-specific update method — setText for text fields, check or uncheck for checkboxes, and select for radio groups and dropdowns — using the value you entered. pdf-lib automatically regenerates each field's visual appearance to reflect the new value, so the change is immediately visible whenever the PDF is opened, not just recorded invisibly in the underlying data. Any field your value can't be applied to (for example, if it's marked read-only in the original PDF) is safely skipped rather than causing the whole operation to fail.
This tool fills in field values while keeping the form fully interactive — the resulting PDF still has real, editable form fields, just with your answers already populated. This is different from 'flattening' a form, a separate operation (not performed here) that would permanently convert filled field values into static page content and remove the ability to edit them further. Keeping the form interactive is usually preferable, since it lets you or anyone else who receives the PDF revisit and adjust individual answers without starting over.
Reading the AcroForm, rendering the generated input controls, and writing your answers back into the PDF are all performed by the pdf-lib JavaScript library running directly in your browser, with no server-side processing step at any point. This means there's no file size limit imposed by an upload restriction, no wait for a network round-trip, and sensitive form data — the kind found in medical intake forms, tax documents, or job applications — never leaves your device.
PDF Form Filler pairs naturally with these PDF tools for finishing and sharing documents.