Free online developer tools.
JSON, JWT, diff, formatting, and more — processed locally, so your data never leaves your machine.
JSON & data
Shape, convert, and fake structured data.
Code & auth
Format code, preview markup, inspect tokens.
Text
Transform and compare plain text.
Everyday utilities
Documents and quick generators.
Learn
Interactive references for core CS concepts.
Why developers use it
Fast, private, and free — the way everyday tooling should be.
Runs in your browser
Privacy is the default. There's no database for your input — every developer tool processes data locally with modern browser APIs.
Developer first
Built by a developer, for developers. No ads, no clutter, keyboard-friendly — just the utilities you need.
Free, no account
No subscriptions, no paywalls, no sign-up. Essential tools for building the web should be free for everyone.
Frequently asked questions
Is my data shared with any third party?
No. Tool input is processed locally in your browser and never sent anywhere. The site uses cookie-free, aggregate analytics (Cloudflare and Vercel) for page views and performance only — see the privacy policy.
Can I use these tools for commercial projects?
Yes — gbkarki.com.np is free for personal, educational, and commercial use.
Do the tools work offline?
Mostly. Because the tools are client-side, once a page has loaded most features keep working without a connection.
What tools are included?
19 tools and references across JSON & data, code, text, documents, and learning — including a JSON Formatter & Validator, JWT Decoder, HTML Editor, ATS Resume Builder, and sorting visualizers.
How can I request a new tool?
Send your idea through the Support page.
A complete toolkit for JSON, code & dev workflows
Having a reliable set of utilities saves hours. Whether you're a frontend engineer debugging state, a backend developer verifying authentication tokens, or a DevOps specialist writing automation, gbkarki.com.np puts the common tasks in one place — no dozen browser tabs, no untrusted third-party sites.
Mastering JSON data management
JSON is the lingua franca of the web, but raw, unformatted JSON is hard to read. The JSON Formatter & Validator validates and beautifies it with tree, table, and raw views, plus auto-fix for common syntax errors.
- Instant validation with clear error locations.
- Minification for smaller network payloads and storage.
- Key conversion (camelCase, snake_case, PascalCase) without touching values.
Learn more about the JSON standard.
Code editors & formatting
Prototype without leaving the browser. The HTML Editor gives you a live HTML/CSS/JS preview, and the Code Formatter beautifies HTML, Java, Python, and MySQL on demand.
Security & token inspection
When you're debugging authentication flows you need to see exactly what's inside your tokens. The JWT Decoder & Signer breaks a JSON Web Token into header, payload, and signature — entirely in your local session, so claims and secrets never touch the network.
Read the JWT introduction to understand how tokens are structured.
Text, data & mock API utilities
The Diff Viewer highlights additions, deletions, and character-level changes between two blocks of text. The Text Converter handles case, URL encoding, and Base64, and the Mock API Generator creates dummy JSON responses for frontend work without a backend.
Documents, utilities & learning
Beyond the IDE: an ATS Resume Builder with PDF export, a QR Generator, and interactive references for HTTP status codes, sorting algorithms, and core data structures.
Find it useful? Pass it on.
Sharing with a teammate is the best way to support the project.