Gapellu PDF Editor
Online Document Automation & Real-Time Invoice Generation SaaS
SaaS
2025
Next.js, Tailwind CSS +3
Enterprise Live
About the Project
Gapellu PDF Editor is a SaaS document automation platform designed for businesses that generate official invoices and purchase orders. WebTech Studio developed its browser-based template editing, live previews, dynamic row calculations, and locked PDF export engine.
Technologies Used
Features & Technical Innovations
Fillable templates for Invoices and Purchase Orders with editable text fields and dynamic tables.
Live preview feature that updates in real-time as users type, ensuring WYSIWYG fidelity.
Easy PDF export with fields embedded and locked for professional use.
Dynamic row addition in tables for itemized billing, with automatic calculations.
Mobile-responsive and touch-optimized UI for teams working on the go.
The Challenge
Gapellu was built to solve the pain of offline PDF editing and manual document prep. Challenges included creating real-time editable overlays on fixed templates, ensuring accurate export layout, and designing a fast, accessible UI for all device types.
Precision in Field Mapping
Accurately aligning input fields with pre-existing template coordinates was essential for professionalism.
User-First Form Experience
Simplifying complex document structures (like dynamic rows) into a smooth UX.
Consistent Output Across Browsers
Ensuring consistency in downloaded PDFs regardless of OS or device type.
Performance with PDF Rendering
Rendering high-resolution templates and handling user inputs without lag or stutter.
Our Solution
Leveraging a combination of React hooks, coordinate-mapped fields, and PDF-Lib, we built a system that allows users to edit business documents with confidence and ease. The UI was fine-tuned for performance, simplicity, and cross-platform usability.
Template-Driven PDF Editing
Mapped input positions over static PDFs using absolute positioning and form state binding.
Preview-As-You-Type Interface
Created a real-time rendering interface using React-PDF that visually updates with every keystroke.
Clean UI with Mobile Optimization
Implemented a responsive, minimalist UI for optimal interaction on phones, tablets, and desktops.
Locked Export with PDF-Lib
Used PDF-Lib to generate non-editable, professional-grade PDFs from filled templates.
Expandable Row Logic
Added dynamic rows in invoice templates with real-time total calculations for each entry.
Why This Project Stands Out
Truly No-Code PDF Editing
No setup, no downloads—just fill and export right in the browser.
Scalable & Ready for Integration
Designed for future integration with CRMs or inventory systems via APIs.
Precision & Usability Combined
Marries a highly visual UI with reliable PDF processing under the hood.
The Results & Business Impact
Used by SMEs and Admin Teams
Businesses in logistics, retail, and services use Gapellu to streamline document generation.
Improved Workflow Efficiency
Reduced document prep time by over 60% compared to manual editing or Word-based templates.
Consistent, Branded Output
Output files are aligned with standard layouts, maintaining branding and professionalism.
Positive Reception from Early Users
Praised for its clean interface, ease of use, and the accuracy of final exports.