Fill PDF forms in your browser: real AcroForm fields, or type over any flat PDF. Add checkmarks, flatten if you want. Free, no upload — files never leave your device.
Fill PDF forms free in your browser — real AcroForm fields or type over any flat PDF; files never leave your device. OpenPDF auto-detects AcroForm fields and turns them into proper text inputs, checkboxes and dropdowns you click and fill in place; PDFs without fields get an overlay mode where you click anywhere to type text or drop ✓/✗ marks. Flattening the result into the page is optional, so the form stays editable until you choose to save, and nothing is ever uploaded to a server.
Yes. If your PDF has real AcroForm fields, OpenPDF detects them automatically and turns them into proper text inputs, checkboxes, and dropdowns you can click and fill in place.
You can still fill it. Use Add text to click anywhere on the page and type, or add checkmark and cross marks — no AcroForm required.
No. Filling runs entirely in your browser with pdf-lib. Your PDF never leaves your device, and nothing is stored on a server.
OpenPDF is an independent project built around one principle: the PDFs you edit should never leave your device. Every tool — merge, split, sign, organize, annotate, compress, watermark, add page numbers — runs entirely in your browser using WebAssembly and modern JavaScript APIs. There is no upload step, no account, no email harvesting, and no premium tier gating the useful features. The codebase and the third-party scripts loaded for analytics and advertising are visible in the page source — Google AdSense and Google Analytics 4 load only after you accept cookies in the consent banner — so anyone can audit what is running before trusting the tool with sensitive contracts, scanned IDs, or financial documents.
By Marco B. · Last updated: