Document Tools
Fill PDF forms, add signatures, and type on any PDF — all in your browser. No uploads, no accounts. Works with tax forms, contracts, and government documents.
What you get
Privacy first
FillFox is designed to be fast, simple, and distraction-free. Open it in any modern browser and get started in seconds — no downloads, no installations, no account required.
Most of our file tools process everything locally in your browser. Productivity tools store data locally by default with optional cloud sync when you sign in.
Get started
Learn more
A research report comparing 3 specialized browser-based PDF tools for merging, form filling, signing, and invoice generation. Feature matrix, pricing breakdown, and use case recommendations included.
We tested the top free PDF form fillers for privacy, features, and ease of use. Here's how they compare when you need to fill tax forms, contracts, and applications online.