Fill & sign PDFs
without uploading
Fill 4 field types, draw or type a signature, and download the finished PDF in 3 steps. Handles files up to 100 MB — tax forms, contracts, rental applications. All processing stays in your browser.
Free online PDF form filler with signature support
No subscriptions required. Zero file uploads. All processing happens locally in your browser.
Fill form fields
Supports 4 interactive field types — text boxes, checkboxes, radio buttons, and dropdowns — in any PDF with native form fields.
Add signatures
2 signature methods: draw with mouse, finger, or stylus, or type your name and render it in a handwriting-style font.
Type on any PDF
Click anywhere on non-fillable PDFs to place text. Works with scanned forms and flat documents that lack interactive fields.
Privacy first
Zero file uploads. All PDF processing runs locally in your browser — files never leave your device.
A PDF form filler that keeps your files on your device
FillFox is a free, browser-based PDF form filler that handles 4 interactive field types — text boxes, checkboxes, radio buttons, and dropdowns — plus text overlays on non-fillable PDFs and electronic signatures. Your files are never uploaded to a server. The app uses pdf.js to render pages and pdf-lib to write your changes back into the PDF, all within your browser's tab.
Online PDF fillers typically require file uploads to remote servers before you can edit anything. FillFox does not. You drop a PDF into the browser, fill the fields or click anywhere to add text, draw or type a signature, and download the finished file. A typical form takes under 60 seconds from drop to download. There is no account to create, no software to install, and no file size limit for Pro users (free tier supports files up to 100 MB).
Common use cases include tax forms, rental agreements, school enrollment paperwork, medical intake forms, and basic contracts. For scanned or "flat" PDFs that lack fillable fields, FillFox lets you click anywhere on the page to place text — so you can fill out virtually any PDF, not just interactive ones. Signatures can be drawn with a mouse, finger, or stylus, or typed and rendered in a handwriting-style font.
How to fill a PDF form in 3 steps
A typical form takes under 60 seconds from drop to download. No account required.
Drop your PDF
Drag and drop or select any PDF up to 100 MB. It loads in your browser — nothing is uploaded to a server.
Fill, sign & annotate
Fill 4 field types, draw or type a signature, or click anywhere to place text on non-fillable PDFs.
Download your PDF
Export the completed document as a PDF. Your filled fields, text, and signatures are baked in.
Pricing
Start free. Upgrade when you need more.
Prices shown exclude applicable taxes.
Free
- Unlimited PDF exports
- Fill interactive form fields
- Add text to any PDF
- Typed signatures
- Drawn signatures with pressure
- Page navigation & zoom
- PDFs up to 100 MB
Pro
- Everything in Free
- No file size limit
- Signature vault (save & reuse)
- Ad-free experience
Crate Pass
Best Value- All Cashew Crate apps
- Everything in Pro
- No ads anywhere
- New apps added regularly
- Cancel anytime
Prices shown exclude applicable taxes.
Frequently asked questions
FillFox processes all PDF files entirely in your browser using JavaScript. Files are never uploaded to any server — the app has no backend that can access, read, or store your documents. Once you close the tab, your PDF data is gone from memory.
FillFox supports both interactive PDFs and non-interactive ("flat") PDFs. For interactive forms, it handles 4 field types: text boxes, checkboxes, radio buttons, and dropdowns. For flat PDFs — like scanned documents or locked forms — you can click anywhere on the page to place text. This covers tax forms, rental agreements, government paperwork, and most other documents.
FillFox offers two ways to sign a PDF. You can draw a signature using your mouse, finger, or stylus on a canvas, or type your name and have it rendered in a handwriting-style font. Both options produce a PNG image that gets embedded directly into the PDF on export. Pro users can also save signatures to a vault for reuse across multiple documents.
FillFox is free for all core features: filling form fields (text boxes, checkboxes, radio buttons, dropdowns), adding text overlays to flat PDFs, and drawing or typing signatures. Free use supports PDF files up to 100 MB with no daily limit. Pro costs $3/month and adds a signature vault for saving and reusing signatures, removes the file size cap, and removes ads.
FillFox works on phones and tablets in any modern mobile browser. You can fill form fields, draw signatures with touch input, type text onto non-fillable PDFs, and download the completed file — all without installing an app. The interface adapts to smaller screens with touch-friendly controls.
FillFox produces electronic signatures that are suitable for most everyday documents — rental agreements, tax forms, school enrollment, HR paperwork, and basic contracts. These qualify as electronic signatures under laws like the US ESIGN Act and EU eIDAS regulation for standard transactions. Some legal contexts (court filings, notarized documents) may require certified digital signatures with PKI verification, which FillFox does not provide.
After cancellation, Pro access continues until the end of your current billing period. Once it expires, you return to the free tier with the 100 MB file size limit. Signatures already saved in your browser remain accessible. You can re-subscribe at any time to regain Pro features.
Email [email protected] with your order number and a description of the issue.