json
JSON Formatter
Format and beautify JSON
Format JSON, encode Base64, calculate age, pick colors, generate UUIDs, test regex, convert units — 100+ free tools in one fast, searchable workspace. No account, no ads, no data collection.
Every tool runs entirely in your browser. No data ever leaves your device.
Popular tools
Fast access to the most useful formatters, encoders, validators, and converters without loading the full library on the homepage.
json
Format and beautify JSON
json
Validate JSON input
base64
Encode text to Base64
base64
Decode Base64 to text
jwt
Decode JWT payload
regex
Test a regex pattern from line 1 against the remaining text
uuid
Generate a UUID
url
Encode text for URLs
url
Decode URL-encoded text
sql
Format SQL queries for easier reading
csv
Convert CSV data into a JSON array
xml
Format and beautify XML with proper indentation
Explore dedicated hubs for all your development domains. From JSON manipulation to cryptography and CSS styling.
JSON (JavaScript Object Notation) is the backbone of modern web APIs and configuration files. Our free JSON tools let you format messy payloads, validate syntax, minify for production, compare two documents for differences, and convert JSON to CSV, XML, or YAML — all without installing anything or uploading your data to a server.
Base64 encoding converts binary data into a set of 64 ASCII characters that can safely travel through text-based protocols like HTTP, email (SMTP), and JSON. Our free Base64 tools cover encoding and decoding for plain text, URL-safe Base64 (used in JWTs and OAuth tokens), images as data URLs, and converting any URL to a Base64 string — all in your browser.
Regular expressions (regex) are a powerful pattern-matching syntax used in almost every programming language. Our free browser-based regex tools let you test patterns against sample text with live highlighting, validate regex syntax, extract all matches, perform find-and-replace operations, and escape special characters — without any backend or signup.
Cryptographic hash functions convert any input into a fixed-length fingerprint that cannot be reversed. Our free online hash tools let you generate MD5 checksums, SHA-256 and SHA-512 hashes, HMAC signatures, Bcrypt password hashes, and CRC32 checksums — and verify file integrity by comparing hash values, all entirely in your browser.
CSV (Comma-Separated Values) is the universal format for exchanging tabular data between spreadsheets, databases, and APIs. Our free online CSV tools let you convert CSV to JSON arrays, convert JSON back to CSV, validate CSV structure for column consistency, and format raw comma-separated data — all without uploading your file to any server.
XML (eXtensible Markup Language) remains the standard for enterprise APIs, SOAP web services, RSS/Atom feeds, Android resource files, and data interchange in banking and government systems. Our free XML tools let you format messy XML into readable indented output, validate XML syntax, and convert XML to JSON — entirely in your browser.
YAML (YAML Ain't Markup Language) is the standard format for Kubernetes manifests, Docker Compose files, GitHub Actions workflows, Ansible playbooks, and most modern DevOps configuration. Our free YAML tools let you format and lint YAML files, validate syntax and indentation, and convert between YAML and JSON — all in your browser.
CSS is the styling language of the web. Our free online CSS tools help you format messy stylesheets for code review, minify CSS to reduce file size and improve page load speed, extract all color values or properties from existing CSS, convert px to rem for responsive design, and visually generate CSS for box shadows, gradients, border radius, and clip paths.
SQL (Structured Query Language) is the universal language for relational databases — MySQL, PostgreSQL, SQLite, SQL Server, and Oracle. Our free SQL tools let you format complex, hard-to-read SQL queries with proper keyword casing and indentation for code review, and minify SQL to compress queries for storage or transmission.
Markdown is the lightweight markup language used for GitHub READMEs, documentation sites, blog posts, and developer notes. Our free Markdown tools give you a live preview renderer, a Markdown-to-HTML converter, and syntax generators for tables, links, images, lists, and fenced code blocks — all in your browser.
Color representation varies across web design, print, and code. Our free color tools let you convert between HEX, RGB, HSL, and CMYK color formats, use a visual color picker to get exact codes, look up any CSS color name to get its HEX and RGB values, and generate a full Tailwind CSS color palette from a base color.
JSON Web Tokens (JWT) are the standard format for authentication and authorization in modern APIs — used by OAuth 2.0, OpenID Connect, Firebase Auth, and most REST APIs. Our free JWT tools let you decode any JWT token to inspect its header, payload claims (sub, iss, exp, iat), and algorithm — all in your browser, without sending tokens to any server.
URLs must follow strict encoding rules to be valid across browsers, servers, and APIs. Our free URL tools cover everything: percent-encoding special characters for safe transmission, decoding encoded URLs back to readable text, parsing any URL into its scheme, host, path, and query components, building query strings from key-value pairs, and extracting all URLs from a block of text.
Secure passwords are the first line of defense for online accounts and systems. Our free password tools let you generate cryptographically strong random passwords with custom length, character sets (uppercase, lowercase, numbers, symbols), check the strength of an existing password, and generate random PINs — all running locally in your browser, never stored or transmitted.
Date and time calculations are a constant source of developer headaches — timezone conversions, epoch timestamps, date arithmetic, and ISO 8601 formatting. Our free date tools cover Unix timestamp conversion, date difference calculation, age calculation, timezone conversion, ISO date formatting, and time duration math — all without leaving your browser.
Whether you are writing content for SEO, academic work, or social media, understanding your text's statistics is essential. Our free text analysis tools count words, characters (with and without spaces), sentences, paragraphs, and lines, calculate reading time by word count, find the most frequently used words, and compute average word length — all instantly in your browser.
String manipulation is one of the most common tasks in development and content work. Our free string tools cover case conversion (upper, lower, sentence, title), string reversal, URL slug generation, removing punctuation, and deleting empty lines — all running instantly in your browser with no backend required.
Quick math calculations should not require opening a spreadsheet. Our free number tools cover percentage calculations, percentage change (increase or decrease), average (mean) calculation, prime number checking, factorial computation, and Roman numeral conversion — all instantly in your browser.
SVG (Scalable Vector Graphics) is the standard format for icons, logos, and illustrations on the web — infinitely scalable without quality loss. Our free SVG tools let you minify and optimize SVG files to reduce size, convert SVG to React JSX components, embed SVG as a CSS background data URI, and preview SVG files directly in your browser.
Create and read QR codes directly in your browser with focused pages for the most common QR intents. Generate URL, WiFi, vCard, text, email, phone, SMS, WhatsApp, social, location, and event QR codes, then download PNG or SVG files without an account, watermark, or server upload.
ASCII (American Standard Code for Information Interchange) assigns a numeric code to every printable character. These tools let you convert plain text to ASCII decimal values and decode ASCII codes back to text — useful for debugging character encoding issues, teaching computing fundamentals, or inspecting binary data streams.
Binary is the base-2 number system used at the lowest level of all digital computers. These tools cover the most common binary tasks: converting text to its binary representation, decoding binary strings back to readable characters, and converting binary numbers to decimal and back. All conversions run instantly in the browser with no upload required.
Hexadecimal (base-16) is widely used in programming, networking, and cryptography because it compactly represents binary data — two hex digits map exactly to one byte. These tools let you convert any text to its hexadecimal representation and decode hex strings back to readable text, making it easy to inspect raw data, debug encoding issues, or work with hash values and color codes.
HTML entities allow special characters like <, >, &, and " to appear safely in HTML documents without being interpreted as markup. These tools handle the most common HTML encoding tasks: escaping characters into entity form for safe display in web pages, decoding entities back to readable text, and converting HTML markup to clean Markdown for content reuse.
These tools handle the conversion between image files and Base64-encoded data URIs — a common pattern for embedding images directly into HTML, CSS, or JSON without referencing external files. Encode an image file to Base64, decode a Base64 string to preview the image, or fetch an image from a remote URL and encode it inline.
ROT13 is a simple substitution cipher that shifts each letter by 13 positions in the alphabet. Applying it twice returns the original text, making it its own inverse. The more general ROT-N variant lets you shift by any number from 1–25. These tools are commonly used to hide puzzle solutions, obscure spoilers, or demonstrate basic cipher concepts.
Open Graph meta tags control how your pages appear when shared on social networks like Facebook, LinkedIn, and Twitter. Getting these tags right improves click-through rates from social shares. These tools help you generate and preview the correct meta tag markup without needing a dedicated marketing platform.
A URL slug is the part of a web address that identifies a specific page — clean, lowercase, and hyphen-separated for readability and SEO. This tool converts any title, heading, or phrase into a properly formatted slug by removing special characters, collapsing spaces into hyphens, and lowercasing everything, following standard URL best practices.
Unicode is the universal character encoding standard that covers virtually every writing system on earth. Unicode escape sequences (like \u0041 for 'A') are used in programming languages, JSON, and configuration files to represent characters that may not render safely in certain contexts. These tools let you encode text to Unicode escapes and decode escape sequences back to their original characters.
Unix timestamps represent a moment in time as the number of seconds (or milliseconds) elapsed since January 1, 1970 00:00:00 UTC. They are the standard way to store and transmit dates in APIs, databases, and log files. These tools convert between Unix timestamps and human-readable dates, generate the current epoch time, and convert timestamps to local timezone-aware date strings.
All-in-one toolkit
FreeToolkit brings together essential browser-based utilities in a single place so you can format payloads, decode strings, validate data, generate values, and move through small development tasks without switching between slow or cluttered tools.
Whether you are checking API responses, cleaning input, transforming structured data, or generating quick development helpers, the toolkit is designed to stay fast, readable, and useful across mobile and desktop screens.
Move from formatting and validation to conversion and generation without leaving the same clean workspace.
All tools run directly in the browser. Your data never touches a server — perfect for sensitive API keys, passwords, and private payloads.
Responsive pages, focused layouts, and direct tool access keep friction low on desktop and mobile.
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FAQ
Quick answers for visitors who want to understand how the library works before diving into the full tool collection.
Yes. Every tool on FreeToolkit runs entirely in your browser using JavaScript. Your data never leaves your device and is never sent to any server. This means you can even use most tools offline once the page is loaded.
Completely free. There are no subscriptions, no premium tiers, and no paywalls. All 100+ tools are available without payment of any kind. The site is supported by non-intrusive advertising.
No account, no email, no login required. Open any tool and start using it immediately. There is no registration process of any kind.
Your data stays 100% private. All processing happens locally in your browser. Nothing is uploaded to any server. You can safely paste API keys, passwords, private JSON data, or any sensitive content without risk.
FreeToolkit focuses on speed, privacy, and depth. Every tool runs locally in the browser (no server round-trips), every tool page has detailed documentation and examples, and the entire library is searchable from one page. No bloat, no forced sign-ups.
Yes. The All Tools page groups the full library into one searchable and filterable view so you can quickly find the exact utility you need across all categories.
Yes. The homepage, All Tools page, and individual tool pages are built with responsive layouts so the interface stays readable and usable across screen sizes from phones to large monitors.
The library includes utilities for JSON, Base64, JWT, regex, UUID, URL handling, password and hash workflows, SQL, CSV, XML, YAML, CSS, SVG, text processing, color conversion, date and timestamp tools, and more — over 100 tools across 20+ categories.