2026 Free PDF Tool Report: Browser-Based Solutions for Forms, Merging, Compression, and Invoicing
Executive Summary
PDF editing has traditionally required desktop software like Adobe Acrobat or server-based services that upload your files for processing. A newer category of browser-based PDF tools now handles merging, splitting, compression, form filling, signing, and invoice generation without uploading files to any server. All processing runs in the browser tab using JavaScript libraries such as pdf-lib, pdf.js, and pdfmake.
This report evaluates 3 specialized PDF tools from the Cashew Crate suite: PaperMint (PDF manipulation), FillFox (form filling and signing), and InvoiceSnap (invoice generation). Each tool targets a different PDF workflow. We compare features, processing models, pricing, and recommended use cases.
Tools Evaluated
PaperMint is a PDF toolkit with 5 tools: merge multiple PDFs into one file, split a PDF into separate pages, compress PDFs across 3 DPI levels (72, 96, and 144), drag-and-drop page reordering, and PDF-to-image conversion (PNG or JPG output). It accepts files of any size, limited only by available device memory.
FillFox is a PDF form filler and document signer. It supports 4 interactive form field types (text boxes, checkboxes, radio buttons, dropdowns) and lets users click anywhere on non-fillable or scanned PDFs to place text. Signatures can be drawn with a mouse, finger, or stylus, or typed and rendered in a handwriting-style font. FillFox uses pdf.js for rendering and pdf-lib for writing changes back into the PDF.
InvoiceSnap is a client-side invoice generator that outputs PDF files. Users fill in business details, client info, and line items, then download a formatted invoice. It supports 25 currencies with localized symbol placement, 3 invoice templates (Classic, Modern, Bold), auto-incrementing invoice numbers (INV-0001, INV-0002, etc.), and automatic subtotal, discount, tax, and total calculations. It generates PDFs using pdfmake.
Feature Matrix
| Feature | PaperMint | FillFox | InvoiceSnap |
|---|---|---|---|
| Merge PDFs | Yes | No | No |
| Split PDFs | Yes | No | No |
| Compress PDFs | Yes (3 DPI levels) | No | No |
| Reorder pages | Yes (drag-and-drop) | No | No |
| Convert to images | Yes (PNG, JPG) | No | No |
| Fill form fields | No | Yes (text, checkbox, radio, dropdown) | No |
| Add signatures | No | Yes (draw or type) | No |
| Type on non-fillable PDFs | No | Yes | No |
| Create invoices | No | No | Yes |
| Auto-numbering | No | No | Yes (INV-0001 sequence) |
| Multi-currency | No | No | Yes (25 currencies) |
| Invoice templates | No | No | Yes (3 templates) |
| Auto-calculations | No | No | Yes (subtotal, discount, tax, total) |
The three tools have no overlapping functionality. PaperMint handles PDF file manipulation, FillFox handles document annotation and signing, and InvoiceSnap handles PDF creation from structured data.
Processing Model
All three tools process data in the browser. No PDF files are uploaded to a server during normal operation.
PaperMint uses pdf-lib for merge, split, reorder, and compress operations. PDF-to-image conversion renders pages via the browser's canvas API. All file I/O happens in browser memory. PaperMint also works offline after the initial page load.
FillFox uses pdf.js (Mozilla's PDF renderer) to display pages and pdf-lib to embed form field values, text overlays, and signature images back into the PDF. The edited PDF is assembled and downloaded entirely within the browser tab.
InvoiceSnap does not process existing PDF files. Instead, it generates new PDF documents from form input using pdfmake, a client-side PDF generation library. The resulting invoice PDF is created in memory and downloaded directly. Business profiles and invoice numbers persist in the browser's localStorage. InvoiceSnap is a static app with no backend database for invoice storage.
For all three tools, closing the browser tab clears the working data from memory. No files are retained on any server.
Pricing Comparison
| Aspect | PaperMint | FillFox | InvoiceSnap |
|---|---|---|---|
| Free tier | 5 operations/day | Unlimited exports, 100 MB file limit | Unlimited invoices |
| Free features | All 5 tools, no file size limits | Form filling, text overlays, typed and drawn signatures | 3 templates, 25 currencies, auto-calculations, PDF download |
| Pro price | $3/mo | $3/mo | $3/mo |
| Pro adds | Unlimited operations, ad-free | No file size limit, signature vault (save and reuse), ad-free | Logo on invoices, business profile saving, ad-free |
| Gating model | Daily limit (5 ops/day) | Feature-gated | Feature-gated |
PaperMint uses a daily operation limit: free users get 5 operations per day across all tools, and Pro removes that cap. FillFox and InvoiceSnap are feature-gated: core functionality is unlimited on the free tier, while Pro unlocks additional capabilities (signature vault for FillFox; logo embedding and business profile saving for InvoiceSnap).
All three apps are included in Crate Pass ($15/mo), which grants Pro access to every Cashew Crate app. Prices exclude applicable taxes.
Use Case Recommendations
Browser Compatibility
PaperMint works in Chrome, Firefox, Safari, and Edge. Chrome and Firefox handle large files best due to their memory management. PaperMint also functions offline after the first page load.
FillFox works on any modern browser including mobile browsers on phones and tablets. Touch input is supported for drawn signatures. The interface adapts to smaller screens with touch-friendly controls (minimum 44px touch targets).
InvoiceSnap runs in all modern browsers. Since it generates PDFs from form data rather than processing uploaded files, memory constraints are not a factor.
All three tools require JavaScript to be enabled.
Conclusion
PaperMint, FillFox, and InvoiceSnap cover distinct PDF workflows with no overlap between them. For users who need to manipulate existing PDF files, fill forms, sign documents, or generate invoices, these three tools handle the most common tasks without uploading files or installing software.