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Fill PDF Forms Online Fill out interactive PDF form fields in your browser.

PDF Form Filler illustration
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PDF Form Filler

Fill out interactive PDF form fields in your browser.

1

Upload PDF Form

Drop a PDF with form fields.

2

Fill Fields

Enter values for detected text, checkbox, and dropdown fields.

3

Download

Save the filled PDF form.

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What Is PDF Form Filler?

The PDF Form Filler automatically detects interactive form fields in your PDF and presents them for editing. Supports text fields, checkboxes, dropdowns, and radio groups. Simply upload your PDF form, fill in the values through an intuitive interface, and download the completed form. The tool preserves all original formatting and non-form content. Ideal for filling out government forms, applications, contracts, or any PDF with interactive fields. All processing stays in your browser — your sensitive form data never leaves your device.

Why Use PDF Form Filler?

  • Auto-detects all form field types
  • Supports text, checkbox, dropdown, and radio fields
  • Preserves original document formatting
  • Sensitive data stays in your browser

Common Use Cases

Government Forms

Fill out tax forms, applications, and permits.

Contracts

Complete contract fields digitally.

Applications

Fill job or school application forms.

Insurance

Complete claim forms and policy documents.

Technical Guide

Uses pdf-lib to load the PDF and access its AcroForm. Iterates through form fields using getForm().getFields(), extracting field names and types. Renders appropriate input controls for each field type (text input for PDFTextField, checkbox select for PDFCheckBox, text input for PDFDropdown and PDFRadioGroup). When filling, uses the corresponding pdf-lib methods: setText, check/uncheck, select. The filled PDF is saved preserving all original content.

Tips & Best Practices

  • 1
    Form fields are auto-detected — no manual setup needed
  • 2
    Leave fields empty to keep their original values
  • 3
    Checkbox values are "true" or "false"
  • 4
    For dropdowns, enter an exact option value

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Frequently Asked Questions

Q What field types are supported?
Text fields, checkboxes, dropdown menus, and radio button groups.
Q What if no fields are found?
The PDF may not have interactive form fields. It might use static text instead.
Q Can I add new fields?
This tool fills existing fields. Use PDF Form Creator to add new fields.
Q Does filling flatten the form?
No, fields remain editable. Use PDF Flatten to make them permanent.
Q Is my data secure?
Yes, all form filling happens locally in your browser. No data is sent anywhere.

About This Tool

PDF Form Filler is a free online tool by FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration or installation required.