Load a PDF, fill its interactive form fields and export, everything stays on your device.
PDF fill lets you complete interactive AcroForm fields in a PDF, text inputs, checkboxes, radio buttons and dropdowns, and download the filled document with pdf-lib.
The tool renders each field at its location in the page so you can fill naturally, and the values are embedded into the PDF when you download. It supports standard AcroForm fields (the most common format), but not signature fields or XFA-based LiveCycle forms.
No. Every operation runs inside your browser tab using JavaScript and WebAssembly. Your file is read into memory on your own device, processed there, and the result is offered as a local download. Nothing is transmitted to Sunasty or any third party. You can verify it yourself: open your browser DevTools, go to the Network tab, and watch, no request carries your file.
The tool supports the main AcroForm field types: single-line and multiline text fields, checkboxes, radio button groups and dropdown lists. Signature fields are not filled by this tool, to sign a document, use the PDF sign tool on Sunasty.
PDF fill writes your values into the interactive AcroForm fields and downloads the result while keeping those fields editable in a viewer. PDF flatten then takes a filled (or annotated) PDF and makes the values permanent and non-interactive, run flatten after fill if you want to lock in the data before sharing.
It works with PDFs that use standard AcroForm fields, which is the most common format. XFA-based forms (used in some Adobe LiveCycle documents) use a different architecture and are not supported by this tool.
Yes, once the page has loaded. Because the processing happens on your device, you can disconnect from the network and the tool keeps working. This is the clearest proof that your data never leaves your machine.
It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.