Developer Tools
Free online developer tools for web development, including code minifiers (CSS, HTML, JS), JSON and YAML converters, JWT decoder, Cron builder, and hashing tools. Built for performance and privacy. Instant processing directly in your browser.
JSON Formatter
Clean, format, and validate your JSON data instantly.
Base64 Encoder / Decoder
Encode and decode data using Base64 encoding scheme.
URL Encoder/Decoder
Securely encode and decode URLs and data strings.
MD5 Hash Generator
Generate secure MD5 cryptographic hashes for any text.
Regex Tester
Test and debug your Regular Expressions in real-time.
SQL Formatter
Format and beautify your SQL queries instantly.
CSS Minifier
Minify CSS files instantly by stripping comments and unnecessary whitespace.
HTML Minifier
Minify HTML by removing comments and extra spaces to optimize loading times.
JavaScript Minifier
Lightweight JS minifier that strips comments and collapses whitespace.
JSON Diff Checker
Compare two JSON objects and view the differences with a unified text diff.
YAML to JSON
Convert YAML to JSON and vice versa instantly as you type.
JWT Decoder
Decode and inspect JWT tokens securely. Check payload claims and expiration.
Cron Expression Builder
Visual cron expression editor that translates cron syntax into plain English.
HTML Entity Encoder
Live-typing HTML entity encoder and decoder with a quick reference table.
Free Developer Tools for Everyday Tasks
FluxToolkit developer tools are built for programmers, web developers, and DevOps engineers who need fast, reliable utilities without the overhead of installing software or signing up for services. Format JSON, minify code, decode tokens, build cron expressions, and more—directly in your browser with zero data transmission.
Essential utilities for modern development
Developer workflows often involve repetitive tasks like formatting code, encoding URLs, or validating JSON. These tools eliminate the friction of manual formatting or searching for syntax online. Whether you are debugging an API response, preparing production code, or testing a regex pattern, everything runs locally for maximum speed and privacy.
Code minification and formatting
Minify CSS, HTML, and JavaScript to reduce file sizes and improve load times. The JSON Formatter validates and pretty-prints JSON with syntax highlighting. The SQL Formatter cleans up messy queries with proper indentation. Each tool preserves your code structure while optimizing output for production or readability as needed.
Data transformation and encoding
Convert between JSON and YAML, encode and decode URLs, handle Base64 encoding for text and files, and format SQL queries. These utilities handle the data transformation tasks that come up during API development, configuration management, and content processing.
Security and authentication utilities
The JWT Decoder parses and validates JSON Web Tokens without sending them to external services. The Hash Generator creates MD5, SHA-1, SHA-256, and SHA-512 hashes for passwords, checksums, and data integrity verification. All processing happens in your browser—no credentials or tokens leave your device.
Developer Tools FAQ
Are these developer tools free to use?
Yes. All FluxToolkit developer tools are completely free with no sign-up required. You can use them instantly from any device with a web browser, whether on desktop, tablet, or mobile.
Is my code or data sent to a server?
No. The developer tools are designed to process everything locally in your browser using JavaScript. Your code, API responses, tokens, and configuration data never leave your device for routine processing tasks.
What is the difference between formatting and minifying code?
Formatting (pretty-printing) adds whitespace and line breaks to make code readable and easy to navigate during development. Minifying removes all unnecessary whitespace, comments, and line breaks to reduce file size for production deployment. Both operations preserve the functional code while optimizing for different use cases.
How do I decode a JWT token?
Paste your JWT token into the JWT Decoder tool. It will parse the header and payload sections, display the algorithm, issue time, expiration, and any custom claims. You can verify signatures by entering your secret key. The tool works entirely in your browser—no token is sent externally.
Can I format SQL queries for different database systems?
The SQL Formatter handles standard SQL syntax and produces clean, indented output compatible with most database systems including MySQL, PostgreSQL, SQLite, and SQL Server. It adds proper line breaks and spacing to make complex queries readable.
What hash algorithms are supported?
The Hash Generator supports MD5, SHA-1, SHA-224, SHA-256, SHA-384, and SHA-512. These can be used for checksums, data integrity verification, or password hashing. Note that MD5 and SHA-1 are cryptographically weak and should not be used for security-sensitive applications.
How do I create a valid cron expression?
Use the Cron Builder tool to visually construct cron expressions. Select the minute, hour, day, month, and weekday using dropdown menus or presets. The tool shows the human-readable schedule and lists the next few execution times so you can verify the expression matches your intent.
Can I test regex patterns with these tools?
Yes. The Regex Tester lets you input a pattern and test strings to see matches highlighted in real time. You can enable case-insensitive and global flags, and the tool explains what parts of your pattern match to help debug complex expressions.
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