44 developer guides, tutorials, and references — all free.
CLAUDE.md is the memory file Claude Code reads at the start of every session. Learn where it lives, what to put in it, and how to write one that actually improves results.
Read articleSkills package reusable instructions and files that Claude Code loads on demand. Learn the SKILL.md format, progressive disclosure, and how to install skills in one command.
ReadThe most useful MCP servers for Claude Code — databases, browsers, docs, and dev platforms — with what each one does and how to install any of them in one command.
ReadTwelve practical habits that make Claude Code faster and more reliable — from writing a strong CLAUDE.md to planning changes, managing context, and building a custom setup.
ReadSkills vs agents vs slash commands in Claude Code, compared plainly: what each is, how it's triggered, when to use it, and how to install each one.
ReadA practical cheat sheet for Claude Code slash commands: every built-in command in one table, plus how to build and install your own custom /commands.
ReadClaude Code is Anthropic's agentic CLI for coding in your terminal. Learn how it works, how to install it, and its core building blocks in this 2026 guide.
ReadA balanced look at Claude Code and Cursor in 2026: terminal agent vs AI IDE, autonomy, extensibility, when to pick each, and how to run both together.
ReadLearn what Claude Code subagents are, how the .claude/agents folder and frontmatter work, and how to install ready-made agents from ToolZip in one command.
ReadConfigure Claude Code with settings.json and CLAUDE.md: the three settings files and their precedence, the permissions allow and deny model, and project memory.
ReadLearn how MCP servers extend Claude Code with databases, browsers, and docs. Configure .mcp.json, pick a transport, and install servers in one command.
ReadLearn how Claude Code slash commands work: the .claude/commands markdown format, arguments, when to use commands vs subagents, and how to install them fast.
ReadLearn how Claude Code hooks run shell commands on lifecycle events to lint on save, block dangerous commands, and fire desktop notifications on their own.
ReadThe best Claude Code agents for developers in 2026: code reviewer, debugger, security auditor, database expert and more, each with a one-line install command.
ReadCurated list of free online developer tools: JSON formatters, regex testers, encoders, converters. Browser-based, private, no signup.
ReadWhat makes a password strong, how entropy works, why length beats complexity, and modern NIST best practices with examples.
ReadCreate QR codes for URLs, Wi-Fi, email, phone, and text. Static vs dynamic, sizing, design tips, and scanning troubleshooting.
ReadReduce image sizes by 60-80% without quality loss. Format selection, responsive images, lazy loading, and Core Web Vitals tips.
ReadRegex patterns for US, UK, international, and E.164 phone numbers. Formatting variations, country codes, and regex vs libraries.
ReadMaster CSS gradients with examples. Linear, radial, conic syntax, color stops, repeating gradients, and creative design patterns.
ReadFix the 10 most common JSON syntax errors: trailing commas, single quotes, unquoted keys, and unexpected tokens with examples.
ReadCompare texts to spot every difference. Online diff tools, command-line diff, VS Code, Git diff, and programmatic comparison.
ReadUse MD5, SHA-256, SHA-512 to verify downloads. Step-by-step instructions for Windows, Mac, and Linux with examples.
ReadSQL formatting standards for readable queries. Indentation, keyword casing, JOIN layout, subqueries, CTEs, and team style guides.
ReadWhat Lorem Ipsum is, why designers use it, when NOT to, 8 creative alternatives, and how much text you need for any design.
Read20 most useful regex patterns for email, URL, phone, date, IP, and password validation. Copy-paste ready with explanations.
ReadHow JSON Web Tokens work: three-part structure, common claims, security best practices, and when to use JWTs vs sessions.
ReadWhat URL encoding is, which characters need it, %20 vs +, and how to encode in JavaScript, Python, and PHP. Practical examples.
ReadDifferences between HEX, RGB, and HSL. When to use each, conversion tips, and practical CSS color management advice.
ReadWCAG contrast ratio requirements for AA and AAA. How to check, fix, and design accessible color combinations for text and UI.
ReadWhat Unix timestamps are, why developers use epoch time, seconds vs milliseconds, timezone pitfalls, and the Year 2038 problem.
ReadComplete Markdown syntax reference: headings, bold, italic, links, images, code blocks, tables, task lists, and GFM extensions.
ReadWhen to use camelCase, snake_case, kebab-case, PascalCase, and CONSTANT_CASE. Conventions for JS, Python, CSS, SQL, and APIs.
ReadFive proven ways to convert Markdown files to PDF — browser-based, Pandoc CLI, VS Code, programmatic, and online converters. Compare quality, learn fixes for common issues (page breaks, code blocks, images), and pick the right method for READMEs, docs, and reports.
ReadCompare MD5 and SHA-256 side by side. Differences in security, speed, output size, and when to use each for checksums and passwords.
ReadCompare JSON and YAML side by side. Key differences in syntax, features, and when each is better for configuration, APIs, and data exchange.
ReadCompare UUID v4, v7, ULID, and NanoID. Differences in randomness, sortability, size, and performance for databases and APIs.
ReadMaster cron syntax with this guide. The 5-field format, special characters, common schedules, and examples for Linux, AWS, and Kubernetes.
ReadDifferences between px, rem, and em in CSS. When to use each for fonts, spacing, and responsive layouts with accessibility best practices.
ReadCompare WebP, AVIF, and PNG image formats. Compression ratios, quality, browser support, and when to use each for web performance.
ReadWhat Base64 encoding is, how the algorithm works, and when to use it. Covers data URIs, JWT tokens, and API authentication with code examples.
ReadThe correct regex pattern for email validation, why simple patterns fail, and implementation in JavaScript, Python, and PHP.
ReadMaster Unix file permissions. Learn what 755, 644, and 777 mean, symbolic notation, and security best practices with an interactive calculator.
ReadValidate JSON data, fix common syntax errors, and learn why validation matters for APIs and configs. Practical examples and free tools.
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