Fill PDF Form
Fill existing AcroForm fields and optionally flatten the completed PDF
About this tool
Fill PDF Form edits fields that already exist in a standard AcroForm PDF. After you choose a file, the tool lists text fields, multiline inputs, checkboxes, radio groups, dropdowns, and option lists with their current values, required flags, and read-only state. You can update supported fields and download either an editable form or a flattened copy whose field appearances are written into the page. This is designed for applications, intake forms, checklists, and QA samples where the field structure is already present. It does not create new fields, edit scanned-page pixels, apply digital signatures, unlock encrypted files, or process XFA forms. Text appearances use the PDF standard Helvetica font; unsupported characters are rejected with a visible error instead of producing a file with missing text. Processing happens locally in the browser, so the PDF and entered values are not uploaded.
Frequently Asked Questions
Which PDF form fields can I fill?
The tool supports existing AcroForm text and multiline fields, checkboxes, radio groups, dropdowns, and option lists. Buttons and signature fields are shown for context but remain read-only.
Can this tool create new fields on a scanned form?
No. A scan is page imagery rather than an interactive form, and this tool only fills fields already defined in the PDF. Use a full PDF form authoring application to add fields first.
Why are XFA forms not supported?
XFA uses a different dynamic form system that pdf-lib cannot reliably edit. When XFA is detected, the tool blocks export rather than creating a PDF whose values may be ignored by the form viewer.
What does flatten after filling do?
Flattening writes the visible field appearances into page content and removes the interactive controls. It is useful for a final submission copy, but the flattened fields cannot be edited later, so keep the original.
Can I enter Chinese, emoji, or other non-Latin text?
The built-in appearance font is standard Helvetica with WinAnsi encoding. If changed text cannot be encoded, the tool stops with a named field error; use a desktop editor that can embed the required font for those characters.
Does it add or validate a digital signature?
No. Signature fields are not modified, and the tool does not create cryptographic signatures. A separate visible-signature tool can place an image, but that is also different from certificate-based signing.
Are the PDF and form values uploaded?
No. Reading fields, applying changes, generating appearances, flattening, and saving all run in your browser. The source PDF and entered values do not leave your device.
Keep browsing