Free Developer Utilities & Encoders
Streamline your engineering workflow with OnlineToolsZone's free developer utilities. Format and validate JSON, decode JWT tokens, minify JavaScript and CSS code, generate secure Base64 hashes, test regular expressions, and convert UNIX timestamps—all from a single, fast developer workbench. Every tool is built with developers in mind: keyboard shortcuts, instant copying, syntax highlighting, and zero telemetry on your payloads. Sensitive strings, access tokens, and private data are processed client-side in your browser wherever possible for maximum security.
HTML Formatter
Format and beautify messy HTML code with proper indentation.
Regex Tester
Test and debug regular expressions with live match highlighting.
Color Converter
Convert colors between HEX, RGB, HSL, and CMYK formats with a live picker.
Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa.
JSON to CSV Converter
Transform structured JSON data into clean CSV spreadsheets and vice-versa.
JWT Decoder
Decode and inspect JSON Web Tokens headers and payload data in your browser.
Markdown to HTML
Convert GitHub Flavored Markdown into semantic HTML with live formatted preview.
Website SEO Auditor
Analyze meta tags, OpenGraph data, headings, and Core Web Vitals for any webpage.
Chemical Engineering Simulator
Interactive sandbox for chemical reaction kinetics, thermodynamics, and mass transfer.
Civil Engineering Simulator
Analyze beam deflection, truss loads, and shear-moment diagrams interactively.
Electrical Engineering Simulator
Simulate AC/DC circuits, RLC resonance, and signal filters in real time.
Engineering Sandbox Hub
Comprehensive suite of engineering modeling tools and physics calculators.
❓ Frequently Asked Questions about Developer Tools
Everything you need to know about formats, privacy, and free usage.
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