Javid
Senior Software Engineer & Founder
Javid is a senior software engineer and founder of SelfDevKit. He builds developer tools with a focus on privacy, offline capability, and native performance.
He also builds products like DroneBundle.com using SelfDevKit. Every tool in SelfDevKit started as something he needed himself.
Articles by Javid
Base64 Decode: How to Decode Base64 Strings, Files, and Data
Learn how to base64 decode strings in every major language, the CLI, and desktop tools. Covers troubleshooting, URL-safe variants, and privacy.
Crontab Generator: How to Build and Debug Cron Expressions
Learn cron syntax, build expressions with a crontab generator, and debug cron jobs that fail silently.
Unix Timestamp Converter: How Epoch Time Works and How to Convert It
Use this unix timestamp converter guide with code examples in 6 languages, seconds vs milliseconds reference, and Y2038 explained.
SQL Formatter Online: Best Tools and Why Offline Might Be Better
Compare the best SQL formatter online tools and learn when offline formatting is the safer, faster choice for developers.
Code Diff Checker: How to Compare Code and Read Diff Output
Learn how to use a code diff checker to compare files, read unified diff output, and spot changes fast.
JSON to TypeScript: How to Generate Type-Safe Interfaces from JSON
Convert JSON to TypeScript interfaces automatically. Learn manual and automated approaches with real code examples.
RGB Color Picker: How RGB Works, CSS Syntax, and Developer Workflows
Use an RGB color picker to find exact color values, convert formats, and write modern CSS with confidence.
Image Converter: The Developer Guide to PNG, JPG, WebP, and More
An image converter transforms files between PNG, JPG, WebP, GIF, and TIFF. Learn each format and why offline conversion matters.
SQL Formatter: How to Beautify and Format SQL Queries
Learn how to format SQL queries for readability. Covers style conventions, code examples, and offline formatting tools.
URL Parser: How to Break Down and Debug URLs Like a Pro
Learn how a URL parser breaks URLs into components like protocol, host, path, and query strings for faster debugging.
HTML Formatter: Beautify, Minify, and Validate HTML the Right Way
Learn how to use an HTML formatter to beautify messy markup, minify for production, and validate your code offline.
UUID Generator: How to Create Unique IDs (v4, v7, ULID, and More)
Generate UUIDs and unique IDs for your projects. Learn which version to use, how they work, and why UUID v7 is replacing v4.
Hex Color Picker: The Developer Guide to Color Formats, Contrast, and Workflows
Use a hex color picker to find exact color codes, convert between formats, and check WCAG contrast.
How to Decode JWT Tokens: GUI, CLI, and Code Methods
Learn how to decode JWT tokens using desktop tools, command-line one-liners, and code in JavaScript, Python, and Go.
Base64 to Image: Decode, Convert, and Troubleshoot
Learn how to convert base64 to image and back with code examples in JavaScript, Python, and Node.js, plus fixes for the most common decoding errors.
JWT Secret Key Generator: How to Create Secure Signing Keys
Learn how to generate a JWT secret key that actually meets RFC 7518 requirements, plus the format decisions developers always get wrong.
JSON to Dart: The Complete Guide for Flutter Developers
Learn every approach to JSON to Dart conversion: manual fromJson, json_serializable, and freezed, with real-world nested object examples.
JSON Minify: How to Compress JSON and Where It Actually Helps
Learn how to JSON minify for production, cut file sizes by up to 40%, and avoid the privacy risks of pasting sensitive data into online tools.
How to Unescape JSON: A Practical Guide for Developers
Learn how to unescape JSON strings in Python, JavaScript, and Go with code examples and debugging tips.
From Web to Native: Building iOS Apps with SelfDevKit Developer Tools
Learn how I use SelfDevKit to build native iOS applications like FeelClose, a long-distance couples app. From debugging Supabase APIs to decoding JWTs, see the developer tools that power mobile development.
Building Real-World Services with SelfDevKit: A Developer Case Study
Learn how I use SelfDevKit to build production services like Is It Visible, a mountain visibility forecasting platform. From JSON debugging to URL encoding, see the developer tools that power real projects.
Regex Tester Guide: Learn Regular Expressions with Practical Examples
Master regex with this comprehensive regex tester guide. Learn regex syntax, common patterns for validation, capture groups, and how to test expressions effectively with real-world examples.
Hash Generator Guide: MD5, SHA256, and Cryptographic Hashing Explained
Learn how hash generators work and when to use MD5, SHA256, SHA512, or BLAKE. Understand hashing for file integrity, password security, and API authentication with practical examples.
Base64 Encode and Decode: Complete Guide for Developers
Learn how to base64 encode and decode text and images. Understand data URIs, when to use Base64, and how to convert images to Base64 strings for HTML, CSS, and APIs.
Secure Password Generator: The Complete Guide to Creating Unbreakable Passwords
Learn how to generate truly secure passwords in 2025. Understand password entropy, strength analysis, and why offline generators are the only safe choice for your credentials.
JWT Decoder & Validator: The Complete Guide to JSON Web Tokens
Learn how to decode, validate, and debug JWT tokens securely. Understand JWT structure, algorithms, claims, and why offline decoders protect your authentication secrets.
JSON Formatter, Viewer & Validator: The Complete Guide for Developers
Learn how to format, view, validate, and debug JSON data efficiently. Discover the best JSON tools for developers and why offline formatters protect your sensitive API data.
Why Offline-First Developer Tools Matter More Than Ever
Discover why privacy-focused, offline developer tools are essential in 2025. Learn how local processing protects your API keys, JWT tokens, and sensitive data while delivering instant performance.
Getting Started with SelfDevKit: The Complete Guide to 50+ Offline Developer Tools
Master SelfDevKit from installation to advanced workflows. Learn how to use JSON tools, JWT decoder, ID generators, and 50+ developer utilities to boost your productivity while keeping your data completely private.