Yuitility
167 browser tools for calculations, text, images and PDFs.
File processing happens on your device. Optional AI chat and contact messages use servers. No sign-up required.
Explore Live Tools • Architecture • Threat Model • Contributing • Changelog
Why Yuitility??
Most web calculators, image converters, and PDF tools suffer from two major flaws:
- Privacy Exposure: They force you to upload sensitive files (tax forms, salary slips, private contracts, client images) to unknown cloud servers just to merge a page or resize a photo.
- Friction and Bloat: They clutter the screen with aggressive ads, paywalls, slow round-trips, and artificial rate limits.
Yuitility solves this fundamentally through browser engineering.
File tools use Canvas, Web Workers, WebAssembly, Web Crypto and in-memory streams to process files locally. Optional AI chat sends messages through the server to the selected provider; contact forms also use the server. Hosting requests and external resource downloads remain network activity.
Features and Capabilities
- Local file processing: Uploaded tool files are processed in browser memory. Downloads are saved by the browser; preferences may persist locally.
- Browser calculations: Calculators run locally after their code loads. Some tools need additional libraries, models or external data.
- 167+ Interactive Tools:
- Developer Utilities: JSON Formatter & Validator, Base64 En/Decoder, JWT Inspector, Regex Tester, Hash Generator, QR Code Engine, Fake Data Generator.
- PDF Suite: Merge, Split, Compress, Rotate, Watermark, Image to PDF, Metadata Editor (powered by in-memory
pdf-lib).
- Media & Image Tools: In-browser AI Background Remover, Image Compressor, Resizer, Format Converter (PNG/JPEG/WebP), Meme Maker, Photo Collage Grid.
- Financial Engines: Home Loan EMI with Prepayment & Tax Savings, SIP Compound Forecaster with Step-Up inflation models, Salary / Take-Home Estimator.
- Academic Conversions: CGPA formula scenarios and custom scales. Institutional applicability must be checked against the user's actual course and regulations.
- Math, Lifestyle & Converters: Scientific Calculator, Unit Converter, Unix Timestamp Engine, Time Zone Calculator, BMI / Body Metric Analyzers.
- PWA caching: Previously loaded tools may work offline. Uncached code, models, external data and AI chat require a connection.
- Embeddable Widgets: Distraction-free, responsive iframe widgets (
/embed/[slug]) for documentation and developer blogs.
Architecture and Tech Stack
User Input ──> In-Memory File Buffer ──> WebAssembly / Web Workers ──> Instant DOM / Canvas / Blob Output
│
(Zero Server Hops)
- Framework: Next.js 16 (App Router) with statically generated content pages and server API routes.
- Language: TypeScript 5.8 configured with strict type-safety.
- Styling: Tailwind CSS v4 with high-contrast Dark Mode support.
- Core Libraries:
pdf-lib, @imgly/background-removal, framer-motion, lucide-react.
- CI/CD & Security: GitHub Actions (Node 20 & 22 matrix), GitHub CodeQL SAST, Dependabot.
- SEO checks: Registry integrity, metadata and internal-link checks, plus a production-preview HTTP crawl. These checks do not establish rankings, accessibility certification or the correctness of every tool.
For full architectural blueprints, see docs/architecture.md.
Quick Start and Local Development
Prerequisites
- Node.js:
v20.x or v22.x (LTS recommended)
- npm:
v10.x or higher
Installation
-
Clone the repository:
git clone https://github.com/anubhav-n-mishra/yuitility.git
cd yuitility
-
Install dependencies:
npm install
-
Start local development:
npm run dev
Open your browser to http://localhost:3000.
Quality Gates and NPM Scripts
All code must pass strict verification gates prior to merge:
| Command | Purpose |
|---|
npm run dev | Starts the local Turbopack development server on port 3000. |
npm run typecheck | Strict TypeScript compilation check via tsc --noEmit. |
npm run lint | Fast static syntax, security marker, emoji prohibition, and path leakage linter. |
npm test | Runs unit tests (batching, deduplication) and static SEO audits. |
npm run build | Compiles optimized production bundle across all 350+ static routes. |
npm run verify | Runs all gates in sequence: typecheck $\rightarrow$ lint $\rightarrow$ test $\rightarrow$ build. |
npm run seo:audit | Enforces SEO title lengths, description bounds, and FAQ schema. |
Security and Privacy
We treat user security as a primary invariant. Please refer to our Security Policy (SECURITY.md) and Security Threat Model for details on our trust boundaries and responsible vulnerability disclosure process.
Contributing
We welcome community contributions, bug fixes, UI improvements, and new client-side tools!
- Please read our Contribution Guidelines (CONTRIBUTING.md) and Code of Conduct (CODE_OF_CONDUCT.md).
- Follow our tutorial on Adding a New Tool.
- Ensure
npm run verify passes with zero errors before opening a Pull Request.
License and Terms
This repository is Source-Available under the Yuitility License.
- You are welcome to: View, clone, study, fork, and test this software locally, and submit Pull Requests or bug reports back to this repository.
- You may NOT: Deploy, host, distribute, or operate public or commercial replicas or competing services using this code or its assets.
Copyright (c) 2026 Anubhav Mishra. All rights reserved.
