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Fill PDF Forms

Fill in PDF form fields directly on the page — free and private.

Use this tool free →

NilPDF Fill Forms scans a PDF for its fillable AcroForm fields and lets you complete them directly on the rendered page, entirely inside your browser. Text fields, checkboxes, and radio buttons all work the same way they would in a desktop PDF reader. When you're done, download the filled PDF as-is with fields still editable, or turn on Flatten to bake your entries permanently into the page and remove the interactive fields. Nothing is ever uploaded to a server.

100% private. Your files are processed entirely inside your browser using WebAssembly. Nothing is uploaded to any server. NilPDF has no backend — there is no server to send your files to.

Frequently Asked Questions

Is filling in a PDF form really free?

Yes — completely free, unlimited use, no account required.

Are my PDF files safe when I fill them in?

Your files never leave your device. All processing happens in your browser using WebAssembly (Pyodide). NilPDF has no server — there is nothing to upload to.

What does "Flatten" do?

Flattening bakes your entered values permanently into the page content and removes the interactive form fields, so the result can no longer be edited as a form. Leave it off if you want the filled PDF to stay editable.

What if my PDF has no fillable fields?

NilPDF will tell you the file has no fillable form fields. Only PDFs with an actual AcroForm (interactive form fields) can be filled this way — a scanned or flat PDF has no fields to detect.