🛠 Developer Tools

{ } JSON Formatter & Validator

Paste your JSON and instantly format, beautify, or minify it. Validates syntax and highlights errors.

📚 Level Up

Clean CodeRobert C. Martin — write better, cleaner code

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🔐 Base64 Encode / Decode

Encode text to Base64 or decode Base64 back to plain text. Supports UTF-8.

📚 Learn More

Web Security for DevelopersReal threats, practical protection

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🆔 UUID Generator

Generate random UUID v4 identifiers instantly. Click to copy, or generate 10 at once.

.* Regex Tester

Test regular expressions with live matching as you type.

📚 Master Regex

Mastering Regular ExpressionsThe definitive regex guide

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#️⃣ Hash Generator

Generate SHA-256, SHA-1, or SHA-512 hashes from any text.

🔐 Security

Cybersecurity EssentialsPractical security fundamentals

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🔗 URL Encode / Decode

Encode special characters for URLs, or decode percent-encoded strings.

📚 Web Dev

Learning Web DesignHTML, CSS, JS fundamentals

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🔑 JWT Decoder

Paste a JSON Web Token to decode its header and payload.

📚 Security

OAuth 2 in ActionUnderstand tokens and auth flows

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🕰 Timestamp Converter

Convert Unix timestamps to human-readable dates and vice versa.

Unix Timestamp Or Human Date

📚 Recommended

The Linux Command LineMaster the terminal

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🎨 Color Converter

Convert between HEX, RGB, and HSL color formats with live preview.

Enter HEX, RGB, or HSL

🎨 Design Tools

Color and Light by James GurneyUnderstand color theory

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📝 Text Diff Checker

Compare two blocks of text line by line.

📚 Version Control

Pro Git BookMaster Git inside and out

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📄 Lorem Ipsum Generator

Paragraphs

📚 Design

Don't Make Me ThinkClassic UX design book

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🔒 Password Generator

Generate secure random passwords with customizable length and characters.

Length Uppercase (A-Z) Lowercase (a-z) Numbers (0-9) Symbols (!@#$...)

🔐 Protect Your Passwords

YubiKey 5 NFCHardware security key — strongest 2FA protection

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📱 QR Code Generator

Generate QR codes from any URL or text instantly.

📱 Recommended

QR Code Sticker PaperPrint your own QR codes

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📝 Markdown Preview

Type Markdown and see a live HTML preview.

📚 Writing

Docs for DevelopersWrite technical documentation that works

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⏰ Cron Expression Parser

Parse cron expressions and understand when they run.

📚 DevOps

The Phoenix ProjectA novel about IT and DevOps

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📋 Git Cheat Sheet

Searchable reference of common Git commands.

📚 Git Mastery

Pro Git BookThe complete Git reference

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🌐 HTTP Status Codes

Complete searchable reference of HTTP status codes.

📚 Web Development

HTTP: The Definitive GuideUnderstand the web protocol

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🔤 ASCII Table

Searchable ASCII character table with decimal codes.

📚 Programming

Code by Charles PetzoldHow computers work from the ground up

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📝 Word & Character Counter

Count words, characters, sentences, and paragraphs. Estimates reading time.

🔤 Case Converter

Convert text to UPPERCASE, lowercase, Title Case, or Sentence case instantly.

🖼 Image to Base64

Convert any image to a Base64 data URI string. Drag and drop or click to select.

⏱ Pomodoro Timer

25-minute focus sessions with 5-minute breaks. The proven productivity technique.

25:00

Focus Time

⏳ Countdown Timer

Set a countdown to any date. See days, hours, minutes, and seconds remaining.

Target Date Label (optional)

.tool-box{display:block!important}Free Online Developer ToolsLifeStack offers free online developer tools including a JSON formatter and validator, Base64 encoder and decoder, UUID v4 generator, regular expression tester, SHA-256 hash generator, URL encoder and decoder, JWT token decoder, Unix timestamp converter, HEX RGB HSL color converter, text diff checker, secure password generator, QR code generator, Markdown preview, cron expression parser, Git cheat sheet, HTTP status codes reference, and ASCII table. All tools run in your browser with no signup required.