Pdf Form Filler

How It Works

1. Opens the PDF template
2. Iterates through form fields
3. Sets values for matching field names
4. Handles checkboxes by setting both /V (value) and /AS (appearance state)
5. Saves the filled PDF

Field Name Matching

Field names should match exactly as they appear in the PDF form. Common patterns:

• German forms: Herr, Frau, Dienstreise, Geschäftsnummer LfF
• English forms: Full Name, Email, Agree, Submit
• Date fields: Date, DOB, Start Date

To discover field names in your PDF, use list_pdf_fields():

from pdf_form_filler import list_pdf_fields

fields = list_pdf_fields("form.pdf")
for field_name, field_type in fields:
    print(f"{field_name}: {field_type}")

Field types:

• text: Text input field
• checkbox: Boolean checkbox
• radio: Radio button
• dropdown: Dropdown select
• signature: Signature field

Example: Job Application Form

fill_pdf_form(
    input_pdf="job_application.pdf",
    output_pdf="job_application_filled.pdf",
    data={
        "Full Name": "Jane Smith",
        "Email": "[email protected]",
        "Phone": "555-1234",
        "Position": "Software Engineer",
        "Years Experience": "5",
        
        # Checkboxes
        "Willing to relocate": True,
        "Available immediately": False,
        "Background check consent": True,
    }
)

Advanced Usage

Partial fills

Only fill specific fields, leave others blank:

data = {"Name": "Jane Doe"}  # Only Name is set
fill_pdf_form("form.pdf", "form_filled.pdf", data)

Dynamic field detection

Get all fields and prompt for values:

from pdf_form_filler import list_pdf_fields

fields = list_pdf_fields("form.pdf")
data = {}
for field_name, field_type in fields:
    if field_type == "text":
        data[field_name] = input(f"Enter {field_name}: ")
    elif field_type == "checkbox":
        data[field_name] = input(f"Check {field_name}? (y/n): ").lower() == 'y'

fill_pdf_form("form.pdf", "form_filled.pdf", data)

Batch fills

Fill multiple PDFs with the same data:

import os
from pdf_form_filler import fill_pdf_form

data = {"Name": "John Doe", "Date": "2026-01-24"}

for filename in os.listdir("forms/"):
    if filename.endswith(".pdf"):
        fill_pdf_form(
            f"forms/{filename}",
            f"forms_filled/{filename}",
            data
        )

Troubleshooting

Checkboxes not showing visually

Some PDF viewers don't render checkboxes immediately. The value is set correctly (/On or /Off), but appearance isn't regenerated. Try opening in:

• Adobe Reader (will render automatically)
• Firefox (has better form support)
• evince or okular on Linux (usually works)

Field names not found

Use list_pdf_fields() to confirm exact field names. PDF forms can be tricky:

• Some use unusual names (e.g., Field_1 instead of descriptive names)
• Some have nested field structures

Text appears cut off

Some PDFs have narrow text fields. Either:

1. Use shorter values
2. Reduce font size in the PDF template itself
3. Manual editing after filling

Bundled Script

See scripts/fill_pdf_form.py for the full implementation using pdfrw.