Free tools that just work.
Fast, practical tools for formatting, encoding, validating, converting, generating, and working with everyday developer data. Everything runs 100% locally in your browser.
Essential Developer Tools
JSON Formatter
JSON ToolsFormat, beautify, and pretty-print JSON data in your browser. Configure indentation (2 spaces, 4 spaces, tabs), pinpoint syntax errors, and copy or download cleanly structured JSON.
JSON Validator
JSON ToolsValidate JSON syntax instantly with detailed error diagnostics. Identify unescaped quotes, trailing commas, missing braces, and structural issues in your JSON payloads.
JWT Decoder
Encoding ToolsDecode and inspect JSON Web Tokens (JWT) client-side. View header algorithms, payload claims, expiration timestamps, and active status without transmitting tokens.
Base64 Encoder
Encoding ToolsEncode plain text, UTF-8 strings, and special characters into Base64 format online. Fast, secure, and client-side conversion compliant with RFC 4648.
UUID / GUID Generator
GeneratorsGenerate cryptographically secure Version 4 (v4) UUIDs and GUIDs using the browser's Web Crypto API. Batch generate single or bulk unique identifiers.
SQL Formatter & Beautifier
Web & Dev ToolsBeautify, format, and indent SQL queries online. Standardize SELECT, INSERT, UPDATE, JOINs, and subqueries with clean uppercase keywords and indentation.
Browse by Category
{ }JSON Tools
Format, validate, minify, escape, and convert JSON data structures
JSON Formatter
Format, beautify, and pretty-print JSON data in your browser. Configure indentation (2 spaces, 4 spaces, tabs), pinpoint syntax errors, and copy or download cleanly structured JSON.
JSON Validator
Validate JSON syntax instantly with detailed error diagnostics. Identify unescaped quotes, trailing commas, missing braces, and structural issues in your JSON payloads.
JSON Minifier
Minify and compress JSON data by stripping unnecessary whitespace, line breaks, and indentation. Reduce payload byte size for faster API responses and optimized storage.
JSON to CSV Converter
Convert JSON objects and arrays into clean CSV spreadsheets. Automatically extract headers, handle nested fields, escape commas, and export to Excel or Google Sheets.
CSV to JSON Converter
Convert CSV data and spreadsheet tables into clean, structured JSON arrays. Automatically parse headers, detect numeric values, and output formatted JSON.
JSON String Escape / Unescape
Escape and unescape JSON strings for safe embedding into code, shell commands, SQL queries, or string literals. Handle double quotes, newlines, and backslashes.
🔐Encoding Tools
Encode and decode Base64, URLs, HTML entities, and inspect JWT claims
Base64 Encoder
Encode plain text, UTF-8 strings, and special characters into Base64 format online. Fast, secure, and client-side conversion compliant with RFC 4648.
Base64 Decoder
Decode Base64 encoded strings back into clean, readable text. Full UTF-8 and multilingual character support with instant error detection for corrupted payloads.
URL Encoder
Encode URLs and query string parameters using standard percent-encoding (RFC 3986). Safely encode spaces, ampersands, slashes, and international characters.
URL Decoder
Decode percent-encoded URL strings and query parameters back into human-readable text. Converts %20, %26, %3F, and UTF-8 hex sequences back into characters.
JWT Decoder
Decode and inspect JSON Web Tokens (JWT) client-side. View header algorithms, payload claims, expiration timestamps, and active status without transmitting tokens.
HTML Entity Encoder
Encode and decode HTML entities online. Convert &, <, >, ", and ' into named or numeric HTML entities (&, <, >, ") to prevent XSS vulnerabilities.
📝Text Tools
Count words, compare diffs, convert casing, and deduplicate lines
Word & Character Counter
Free online word counter and text statistics analyzer. Calculate word count, character count (with/without spaces), sentences, paragraphs, and reading time in real time.
Character Counter
Count exact characters, letters, digits, spaces, and byte lengths in real time. Ideal for SEO meta descriptions, social media character limits, and string validation.
Text Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case, UPPERCASE, lowercase, and Title Case. Clean and normalize variable names and headlines.
Text Diff Checker
Compare two text snippets or code blocks side by side. Highlight additions, deletions, and inline differences with color-coded visual diffing.
Duplicate Line Remover
Remove duplicate lines from text lists, CSV records, and logs. Options for case-sensitive deduplication, sorting alphabetically, and stripping empty lines.
⚡Generators
Generate UUIDs, secure passwords, QR codes, hashes, and timestamps
UUID / GUID Generator
Generate cryptographically secure Version 4 (v4) UUIDs and GUIDs using the browser's Web Crypto API. Batch generate single or bulk unique identifiers.
Cryptographic Hash Generator
Compute cryptographic hashes (SHA-256, SHA-512, SHA-384, SHA-1, MD5) in real time using the native Web Crypto API. 100% private client-side execution.
Secure Password Generator
Generate random, cryptographically strong passwords using browser CSPRNG (Web Crypto API). Configure length, numbers, symbols, and view entropy strength.
QR Code Generator
Generate custom QR codes online for URLs, text, Wi-Fi networks, and contact info. Download high-resolution PNG QR codes instantly with zero tracking.
Unix Timestamp Converter
Convert Unix epoch timestamps (seconds and milliseconds) to human-readable UTC and local date formats, or convert dates into Unix epoch seconds.
Lorem Ipsum Placeholder Generator
Generate custom Lorem Ipsum dummy text for design mockups, wireframes, and website prototypes. Generate paragraphs, sentences, or word counts instantly.
🌐Web & Dev Tools
Format SQL & XML, parse URLs, convert color codes, and test RegEx
SQL Formatter & Beautifier
Beautify, format, and indent SQL queries online. Standardize SELECT, INSERT, UPDATE, JOINs, and subqueries with clean uppercase keywords and indentation.
XML Formatter & Beautifier
Format, pretty-print, and indent XML documents online. Check tag nesting, clean whitespace, and beautify RSS feeds, SOAP payloads, and SVG files.
YAML Formatter & Validator
Format, clean, and validate YAML configurations online. Standardize indentation for Docker Compose, Kubernetes manifests, and GitHub Actions workflows.
RegEx Tester & Debugger
Test and debug regular expressions online in real time. Highlight match groups, test flags (g, i, m, s), and validate regex patterns with JavaScript engine accuracy.
Color Code Converter
Convert color codes instantly between HEX, RGB, HSL, HSV, and CMYK. Preview color palettes, copy CSS color values, and adjust alpha transparency.
URL & Query String Parser
Parse and break down URLs into protocol, hostname, port, path, query parameters, and hash fragments. Inspect and debug URL query string keys and values.
Latest Technical Guides
In-depth documentation, standards breakdowns, and real-world code examples.
What Is JSON? The Complete Guide to JavaScript Object Notation
A comprehensive guide to JSON (JavaScript Object Notation). Learn JSON syntax, data types, objects, arrays, practical API examples, and standard serialization practices.
JSON Syntax Explained: Grammar, Types & RFC 8259 Rules
Deep dive into RFC 8259 JSON syntax rules. Learn precise escaping sequences, string encoding, number formatting, and bracket balancing to write valid JSON.
How to Validate JSON: Syntax Checking & Schema Strategies
Learn how to validate JSON data online, programmatically in JavaScript, Python, and Go, and using JSON Schema ($schema) for robust API contracts.
How to Format & Pretty-Print JSON: Tools & Code Techniques
Learn how to format and pretty-print JSON online, in VS Code, with CLI tools like jq, and programmatically in Python and JavaScript.
Why Developers Choose ToolNest
100% Client-Side Privacy
Everything runs directly in your browser via Web APIs. Your JSON, secrets, tokens, and payloads never leave your computer.
Zero Latency Execution
No waiting on backend servers or queuing requests. Tools process your input instantly in memory with real-time feedback.
Always Free & Open
No accounts, no subscriptions, and no paywalls. Every utility is available immediately whenever you need it.
Responsive & Accessible
Designed for speed and keyboard navigation. Clean layouts that work on desktops, laptops, tablets, and phones.
Built by AfriBa Labs
ToolNest is developed and maintained by AfriBa Labs, an independent software studio focused on building practical digital products and useful tools.
Visit AfriBa Labs→