FillDef — Private PDF Filler & Web Form Autofill

Companion to the FillDef PDF filler. Autofills web forms from your encrypted profile. Encrypted on-device — we can't read it.

FillDef is a private PDF filler — and this Chrome extension brings the same encrypted profile to web forms. The main FillDef product is a web app at filldef.com that fills and signs fillable PDFs (W-9, NDAs, vendor onboarding, government forms, leases) entirely in your browser. PDF bytes never leave your device. This extension is the optional companion: install it when you also want one-click autofill on web forms — job applications, signups, tax portals — using the same encrypted profile. Your profile is encrypted on your device before it ever touches our servers — we can't read it. ✨ WHY PEOPLE INSTALL THIS • You already use FillDef for PDFs and want web forms covered too. • You're tired of password managers half-filling complex forms and giving up on the rest. • You don't want a Chrome extension reading every keystroke and sending it to an AI server. ⚡ WHAT IT DOES • Detects form fields on any page and maps them to your saved profile in milliseconds. • A local pattern dictionary handles 80–90% of common English fields instantly, with no network call. • Lets you click a field after fill to swap in a different saved value. • Mirrors your profile (encrypted with AES-256-GCM) into browser.storage.local as a local cache so autofill works instantly and offline. The canonical copy lives encrypted on FillDef's servers (we can't decrypt it) — uninstalling the extension does not delete your profile. • Shares one credit balance with the FillDef PDF filler. 5 fills are free every month; credit packs start at $1.99 and never expire. 🤖 HOW THE AI FALLBACK WORKS For unusual or non-English field labels (e.g. "Steueridentifikationsnummer"), the extension sends the field LABEL only — no profile values, no page content, no document content — to a Gemini model via the FillDef Edge Function. The AI matches the label to a profile key like "tax_id." Your actual data never leaves the browser. You can verify in DevTools → service worker → Network: the only outgoing request body contains field labels. 🔒 PRIVACY ARCHITECTURE • Profile encrypted with AES-256-GCM via the Web Crypto API. Encryption key derived from your account and never leaves your browser. We store only the ciphertext on our servers — we can't decrypt it. • PDFs are processed by the web app at filldef.com using PDF.js + pdf-lib — fully client-side; PDF bytes never reach a server. • AI requests carry only field labels (e.g. "First name"), never values. • Manifest V3, no remote code, no analytics SDK in the extension. ✅ WHAT YOU NEED • A free FillDef account (sign up at filldef.com — takes 30 seconds). • Chrome (Firefox and Edge are on the roadmap). 🚫 WHAT IT DOES NOT DO • Does not auto-submit forms — you always review before sending. • Does not solve captchas or attempt anything bot-like. • Does not record what you filled or where. • Does not work on legal e-signature flows (DocuSign-style PKI). 🔗 LEARN MORE • Web app: https://filldef.com • Privacy details: https://filldef.com/privacy • Pricing: https://filldef.com/pricing