All 60 Free Developer Tools
The complete directory of every tool on FastDevKit. JSON formatters, encoders, generators, CSS builders, and more — all free, all client-side, no signup required.
Encoding & Decoding Tools
Encode, decode, and convert data between different formats instantly in your browser.
Base64 Encoder / Decoder
Encode or decode any text and files to and from Base64 format with one click.
Base64 Encode & Decode Online
A dedicated online Base64 encoding and decoding tool with file support and batch mode.
Image to Base64 Converter
Convert images (PNG, JPG, SVG, GIF) to Base64 data URIs for embedding in HTML and CSS.
Base64 to Image Converter
Decode a Base64 string back into a downloadable image file with preview.
URL Encoder / Decoder
Percent-encode or decode URLs and query strings for safe transmission in HTTP requests.
HTML Entity Encoder / Decoder
Convert special characters to HTML entities and vice versa to prevent XSS and display issues.
String Escape / Unescape
Escape and unescape strings for JSON, HTML, XML, CSV, and JavaScript contexts.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal (base 2/8/10/16).
Generators & Builders
Generate UUIDs, passwords, QR codes, placeholder content, and more with customizable options.
UUID Generator
Generate RFC 4122 compliant UUIDs (v1 and v4) in bulk with copy-to-clipboard support.
Generate UUID Online
Quick online UUID/GUID generator with formatting options and batch generation up to 1000.
Password Generator
Create strong, cryptographically secure passwords with customizable length, symbols, and entropy display.
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words for mockups and prototypes.
Cron Expression Generator
Build and validate cron expressions visually with plain-English explanations and next-run previews.
Crontab Guru
An interactive crontab expression editor with real-time parsing, examples, and next execution times.
QR Code Generator
Create QR codes for URLs, text, Wi-Fi credentials, and vCards with customizable size and colors.
Placeholder Image Generator
Generate custom placeholder images with specific dimensions, colors, and text overlays.
Meta Tag Generator
Generate SEO-optimized meta tags, Open Graph, and Twitter Card markup for your web pages.
JWT Generator
Create signed JSON Web Tokens with custom claims, expiration, and algorithm selection (HS256, RS256).
Markdown Table Generator
Build Markdown tables visually with a spreadsheet-like interface and auto-alignment.
Security & Hashing Tools
Hash data, decode tokens, inspect HTTP security headers, and analyze network requests.
Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes of any text or file instantly.
JWT Decoder
Decode and inspect JSON Web Token headers, payloads, and signatures without any server calls.
HTTP Headers Reference
Browse a complete reference of HTTP request and response headers with security best practices.
HTTP Status Codes
Comprehensive reference for all HTTP status codes (1xx–5xx) with descriptions and use cases.
Chmod Calculator
Calculate Unix file permissions in symbolic and octal notation with an interactive checkbox UI.
IP Address Lookup
Look up geolocation, ISP, ASN, and timezone information for any IP address or your own.
Text & Code Processing
Format, minify, validate, diff, and transform text, JSON, SQL, Markdown, and more.
JSON Formatter & Beautifier
Format, beautify, and validate JSON with syntax highlighting, tree view, and customizable indentation.
JSON Format Online
A fast online JSON formatter with collapsible tree view, search, and minify/beautify toggle.
JSON Validator
Validate JSON syntax with detailed error messages pointing to the exact line and character.
JSON Path Evaluator
Query and extract data from JSON documents using JSONPath expressions with live preview.
JSON Diff Viewer
Compare two JSON documents side-by-side with highlighted additions, deletions, and changes.
JSON to TypeScript
Convert JSON objects to TypeScript interfaces and types automatically with nested support.
JSON to CSV Converter
Convert JSON arrays to CSV and CSV files to JSON with header mapping and delimiter options.
Text Diff Checker
Compare two blocks of text and see additions, deletions, and modifications highlighted inline.
Regex Tester
Test JavaScript regular expressions in real time with match highlighting, groups, and flag toggles.
Regex Cheatsheet
A quick-reference guide for regular expression syntax, quantifiers, anchors, and lookarounds.
SQL Formatter
Format and beautify SQL queries for MySQL, PostgreSQL, SQLite, and T-SQL with customizable style.
SQL to MongoDB Query
Translate SQL SELECT statements to MongoDB find() and aggregate() query syntax.
Markdown Preview
Write Markdown on the left and see a live HTML preview on the right with GFM support.
Markdown to HTML
Convert Markdown text to clean HTML with optional syntax highlighting and copy support.
HTML Prettifier
Format and indent messy HTML into clean, readable code with customizable indentation.
HTML to JSX Converter
Convert HTML markup to valid JSX for React components, handling class, style, and attributes.
CSS Minifier
Minify CSS stylesheets by removing whitespace, comments, and redundant code to reduce file size.
JavaScript Minifier
Compress and minify JavaScript code to reduce bundle size for faster page loads.
YAML / JSON Converter
Convert between YAML and JSON formats bidirectionally with validation and formatting.
TOML Converter
Parse and convert TOML configuration files to JSON and back with syntax validation.
Case Converter
Convert text between camelCase, snake_case, kebab-case, PascalCase, UPPER_CASE, and more.
Text Counter
Count characters, words, sentences, paragraphs, and estimate reading time of any text.
Converters & Utilities
Convert timestamps, units, data formats, and inspect Open Graph metadata.
Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa across multiple timezones.
Epoch Converter
Convert epoch/Unix time to date and date to epoch with millisecond precision and timezone support.
Unit Converter
Convert between units of length, weight, temperature, data size, speed, and more.
SVG to CSS Background
Convert SVG code to a CSS background-image data URI with URL encoding and optimization.
OG Debugger
Preview how your page looks when shared on social media by fetching Open Graph and Twitter Card meta.
Twitter Card Validator
Validate and preview Twitter Card meta tags to ensure your content looks great when shared.
Design & CSS Tools
Generate CSS layouts, gradients, shadows, and pick colors with visual editors.
Color Picker
Pick colors with a visual editor and convert between HEX, RGB, HSL, and CSS named colors.
CSS Gradient Generator
Create beautiful linear and radial CSS gradients with a visual editor and copy-ready code.
Box Shadow Generator
Design CSS box shadows visually with multiple layers, inset, blur, and spread controls.
Flexbox Playground
Learn and experiment with CSS Flexbox properties using an interactive visual playground.
CSS Grid Generator
Build CSS Grid layouts visually by defining rows, columns, gaps, and areas with live preview.
Aspect Ratio Calculator
Calculate and convert aspect ratios for images, videos, and responsive design containers.
Frequently Asked Questions
What are the best free developer tools available online?
FastDevKit offers 60 free developer tools including JSON formatter, Base64 encoder/decoder, UUID generator, regex tester, hash generator, JWT decoder, CSS generators, and many more. All tools run entirely in your browser with no signup or installation required.
Are these online coding tools safe to use with sensitive data?
Yes. Every tool on FastDevKit processes data 100% client-side in your browser. Your data never leaves your device and is never sent to any server, making them safe for use with API keys, tokens, and other sensitive information.
Do I need to create an account to use these developer tools?
No. All 60 tools on FastDevKit are completely free and require no signup, login, or account creation. Just open any tool and start using it immediately.
Can I use these tools on mobile devices?
Yes. All FastDevKit tools are fully responsive and work on smartphones, tablets, and desktop browsers. The interface adapts to your screen size automatically.
What types of developer tools does FastDevKit offer?
FastDevKit provides tools across six categories: Encoding & Decoding (Base64, URL, HTML entities), Generators (UUID, password, QR code, cron), Security (hash, JWT, chmod), Text & Code (JSON, SQL, regex, Markdown), Converters (timestamp, units, YAML), and Design (color picker, gradients, Flexbox, Grid).
How do these tools compare to paid alternatives like DevUtils or CyberChef?
FastDevKit provides the most commonly needed developer tools in a fast, web-based interface with zero installation. Unlike desktop apps, it works on any device with a browser. Unlike CyberChef, it has a clean modern UI designed for quick daily tasks. All 60 tools are free forever.
Start Using Free Developer Tools Now
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