Fillable uses browser-side PDF parsing to auto-detect form fields for a one-time $4 fee

Fillable is a one-off web tool that converts flat, non-interactive PDFs into fillable forms without requiring a subscription. It works entirely in the browser, using pdf.js to replay each page's drawing instructions and identify lines, rectangles, and text that indicate form fields. The tool applies rule-based classification to distinguish checkboxes, text fields, date fields, signature fields, and table cells based on geometry and nearby label text. Edge cases such as zip codes and multi-line fields are handled through specific logic refined from real-world form testing. Users pay a single $4 fee per document, and the server independently validates all coordinates before writing the final PDF.