Client-side
JSON Formatter Online: Format, Validate & Minify Instantly
Use this JSON formatter online to format, validate, and minify JSON instantly. Also converts XML to JSON and JSON to XML — all free, no server uploads.
Developer tools, guides,
and cheat sheets
Free browser-based tools, language guides, and quick-reference cheat sheets. Fast, distraction-free, and built for developers who ship.
Popular tools
View all tools → Client-side
Base64 Encoder/Decoder — Free Online Tool
Encode and decode Base64 strings instantly in your browser. Supports standard text and URL-safe Base64 formats — no data sent to servers.
Client-side
Regex Tester — Free Online Tool
Test regular expressions against text with real-time match highlighting. See all matches, groups, and an explanation of your pattern.
Client-side
JWT Decoder — Free Online Tool
Decode and inspect JWT tokens instantly in your browser. Parses header, payload, and shows expiry. No verification — client-side only.
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See all languages →Trending cheat sheets
All cheat sheets →CSS Border Cheat Sheet: Selectors and Properties
CSS border properties, selectors, the box model, colors, flexbox, and pseudo-classes covered in one quick-reference cheat sheet for web developers.
Markdown Cheat Sheet: Complete Reference for Developers
Markdown cheat sheet with horizontal rule markdown syntax, text formatting, links, tables, code blocks — your complete quick reference for writing docs.
Python String Methods: split, join, replace, strip & More
Python string methods cheatsheet: every built-in str method with syntax, working examples, and pitfalls — split, join, replace, strip, casefold, and more.
Git Commands Cheat Sheet
The complete git commands cheat sheet: setup, staging, branching, merging, remotes, stashing, history, undoing, and recovery — all in one place.
Linux Commands Cheat Sheet
Linux commands cheatsheet covering bash commands, file management, permissions, process control, networking, and terminal commands for developers.
Docker Commands Cheat Sheet
Complete docker commands cheatsheet covering docker run, Dockerfile, containers, images, volumes, networks, and Docker Compose for every stage of development.
Regex Cheat Sheet
The complete regex cheatsheet: character classes, anchors, quantifiers, groups, lookaheads, flags, and validation patterns for Python and JavaScript.
CSS Flexbox Cheat Sheet
Master CSS Flexbox with this cheat sheet covering flex container and flex item properties, alignment, ordering, and responsive layout patterns with examples.
Latest from the blog
All posts →Collapsible HTML Tags, Attributes and Elements Reference
Collapsible HTML with <details> and <summary> explained, plus a reference for essential HTML tags, attributes, and semantic elements every developer needs.
What Are Indexes in SQL? A Complete Guide
What are indexes in SQL? Learn how database indexes work, which types exist, when to use them, and how to create indexes that make queries faster.
Stack vs Heap Memory: Key Differences Explained
Understand stack and heap memory: how each works, when to use them, and how to avoid common memory pitfalls like stack overflows and memory leaks.
Parsing JSON in PHP: json_decode() Without the Surprises
Master php json decode: choose arrays or objects, handle the null ambiguity, avoid big-integer precision loss, and build a reliable decode function.
TypeScript Tuples: Fixed-Length Typed Arrays Explained
Learn what typescript tuples are, how they differ from arrays, and how to use labeled, optional, and readonly tuples with real examples and common pitfalls.
What Is a Cross Join in SQL? Examples Explained
Learn what is cross join in SQL, how it generates a Cartesian product, when to use it, and see practical examples in MySQL, PostgreSQL, and more.