PDF Form Filler
Fill interactive PDF form fields directly in your browser. Detect and fill text fields, checkboxes, dropdowns, and radio buttons — no upload required.
How to Use
Fill PDF forms in four steps:
- Upload your PDF form — Drag and drop or click to browse. The tool automatically detects all interactive form fields and displays them in an editable list.
- Fill in the fields — Type text into text fields, check or uncheck checkboxes, select dropdown options, and choose radio button values. Each field shows its name and type.
- Choose output options — Enable Flatten to permanently embed your entries into the page content, making the form non-editable. Leave it off to keep fields interactive.
- Save and download — Click Save Form to generate the filled PDF. Download the result for printing, sharing, or submission.
All processing runs in your browser using pdf-lib. No files leave your device.
About This Tool
PDF forms use the AcroForm standard defined in the PDF specification to embed interactive fields directly into documents. Unlike HTML forms that exist as separate elements, PDF form fields are overlaid on page content at specific coordinates, with their visual appearance defined by appearance streams and their data stored in the document's AcroForm dictionary.
How pdf-lib reads and writes form fields
pdf-lib provides a high-level PDFForm API that abstracts the complexity of AcroForm dictionaries. The getForm() method returns an object with typed field accessors — getTextField(), getCheckBox(), getDropdown(), and getRadioGroup(). Each returns a typed object with methods like setText(), check(), or select(). When the document is saved, pdf-lib automatically updates both the field value and its appearance stream.
The AcroForm dictionary structure
The document catalog contains an /AcroForm dictionary with a /Fields array referencing all top-level field objects. Each field dictionary contains /T (field name), /FT (field type: Tx, Btn, Ch), /V (current value), and /Rect (position on the page). Fields can have children — radio buttons share a parent field name but have individual widget annotations for each option.
Form flattening and its implications
Flattening a form converts interactive fields into static page content. The field values are drawn directly into the page content stream, and the AcroForm dictionary is removed. This is the standard approach for final document distribution — it ensures that the filled values appear identically in every PDF viewer, prevents further editing, and reduces file size by removing form metadata. Flattening is typically required for court filings, insurance claims, and government form submissions.
All processing happens client-side in your browser. To permanently embed form data, use the flatten option. To remove form interactivity from any PDF, try PDF Flatten. To add stamps or watermarks after filling, use PDF Add Stamps.
Why Use This Tool
Filling PDF forms in the browser addresses common document workflow needs:
- No software required — Many users don't have Adobe Acrobat or other PDF editing software. Browser-based form filling works on any device with a modern browser, including Chromebooks and tablets.
- Government and legal forms — Tax forms, permit applications, and court filings are often distributed as fillable PDFs. This tool lets users complete them without purchasing specialized software.
- HR and onboarding — Employment forms, W-4s, direct deposit authorizations, and benefits enrollment documents are commonly fillable PDFs that need quick completion.
- Insurance and healthcare — Claim forms, pre-authorization requests, and patient intake forms are frequently distributed as fillable PDFs with strict formatting requirements.
- Education — Scholarship applications, enrollment forms, and administrative paperwork at educational institutions often use fillable PDF formats.
- Privacy — Forms containing Social Security numbers, medical information, financial data, or other sensitive information should never be uploaded to third-party servers. This tool processes everything locally.
Every document stays on your device — critical for forms containing personal, medical, financial, or legal information.