JSON Formatter
Beautifies or minifies JSON.
Developer Tools
Everyday utilities for formatting and validating code, converting data formats, generating keys and CSS, and writing server config. Every tool runs in your browser, so nothing you paste is sent to a server.
All Developer Tools
JSON Validator
Checks JSON syntax and explains any error in plain English.
UUID Generator
Generates random v4 and time-ordered v7 UUIDs.
URL Encoder / Decoder
Percent-encodes and decodes text for URLs.
Base64 Encoder / Decoder
Encodes and decodes Base64 for text and files.
Unix Timestamp Converter
Converts between Unix epoch time and readable dates, in both directions.
Hash Generator
Computes checksums of text or files and compares them with an expected hash.
JWT Decoder
Decodes JSON Web Tokens, explains the claims, and verifies HS, RS, PS, and ES signatures.
Regex Tester
Highlights regex matches live, lists capture groups and offsets, and previews replacements.
Cron Expression Parser
Explains cron schedules in plain English and lists the next run times.
Diff Checker
Compares two texts or code files and highlights added, removed, and changed lines.
Color Converter
Converts colors between HEX, RGB, HSL, HSV, and CMYK and checks WCAG contrast.
Password Generator
Creates strong random passwords with a chosen length and character set.
JSON Viewer
Shows JSON as a collapsible tree with search and copyable paths.
JSON Schema Validator
Validates JSON data against a JSON Schema (draft 2020-12 or draft-07) and lists every error.
XML Formatter
Beautifies XML with clean indentation or minifies it to one line.
XML Validator
Checks XML for well-formedness and explains each syntax error.
XML to JSON Converter
Converts XML into readable JSON, with attributes and repeated elements handled.
JSON to XML Converter
Converts JSON into well-formed, indented XML.
XML to YAML Converter
Converts XML into readable YAML, keeping attributes and repeated elements.
YAML to XML Converter
Converts YAML documents into well-formed, indented XML.
HTML to YAML Converter
Turns HTML markup into a YAML tree of elements, attributes, and text.
YAML Validator & Formatter
Finds YAML syntax errors by line and reformats YAML with clean indentation.
HTML Formatter
Beautifies HTML with consistent indentation, including inline CSS and JavaScript.
CSS Formatter
Beautifies CSS with one declaration per line and consistent indentation.
JavaScript Formatter
Beautifies minified or messy JavaScript with your chosen indent and brace style.
CSS Minifier
Minifies CSS and shows the size saving, raw and gzipped.
JavaScript Minifier
Minifies JavaScript with Terser and reports the size saving.
SQL Formatter
Formats SQL queries for MySQL, PostgreSQL, SQLite, SQL Server, and more.
PHP Formatter
Re-indents PHP code safely without touching strings, comments, or inline HTML.
GraphQL Formatter & Validator
Formats or minifies GraphQL queries and schemas and reports syntax errors.
OpenAPI Validator
Checks OpenAPI 3.x and Swagger 2.0 specs for structural errors and broken $refs.
Markdown Preview
Live Markdown editor with GitHub-flavored preview and HTML export.
cURL Command Builder
Builds copy-ready cURL commands with headers, auth, and a body, quoted for your shell.
.htaccess Redirect Generator
Generates .htaccess redirect rules for pages, HTTPS, www, and domain moves.
.htaccess Validator
Checks .htaccess files for unknown directives, unclosed blocks, and bad rewrite rules.
Htpasswd Generator
Creates .htpasswd lines with bcrypt, APR1-MD5, or SHA-1 hashes for Basic Auth.
Robots.txt Generator
Creates robots.txt rules for search and AI crawlers and tests URLs against them.
Web App Manifest Generator
Creates a web app manifest and the HTML tags to make a site installable.
HTML Form Generator
Builds accessible HTML forms field by field with a live preview.
SQL Query Generator
Generates CREATE, INSERT, SELECT, UPDATE, and DELETE statements for four databases.
Sed Command Generator
Builds sed commands for substitution, deletion, printing, and inserts, with a live preview.
Sed Command Validator
Checks sed command syntax and explains each part in plain English.
PHP Serialize / Unserialize
Converts PHP serialized strings to readable JSON and back, safely.
Printf Format Tester
Runs printf and sprintf format strings with test arguments and explains each placeholder.
HMAC Generator
Signs text or files with HMAC-SHA256 and other hashes, and checks signatures.
Bcrypt Generator
Creates bcrypt password hashes and checks passwords against existing hashes.
RSA Key Generator
Creates RSA key pairs as PEM, OpenSSH, and JWK, entirely in the browser.
Basic Auth Header Generator
Builds and decodes HTTP Basic Authorization headers.
TOTP Generator
Shows live TOTP codes from a secret, verifies codes, and makes the setup QR code.
Random Token Generator
Generates secure random tokens and API keys with a chosen length, alphabet, and prefix.
WordPress Salt Generator
Generates the eight wp-config.php keys and salts in ready-to-paste form.
Blowfish Secret Generator
Generates phpMyAdmin's blowfish_secret for config.inc.php, old and new formats.
Password Strength Checker
Estimates how guessable a password is and explains what weakens it.
HTML Entity Encoder / Decoder
Encodes text into HTML entities and decodes named, decimal, and hex entities.
URL Parser
Breaks a URL into its parts and lets you edit query parameters.
MIME Type Lookup
Finds MIME types by extension and detects a file's real type from its content.
CSS Gradient Generator
Builds linear, radial, and conic CSS gradients visually and copies the CSS.
Box Shadow Generator
Designs layered and inset CSS box shadows with a live preview.
Text Shadow Generator
Creates CSS text shadows, glows, and outlines on your own preview text.
Border Radius Generator
Shapes corners with CSS border-radius, including elliptical blob shapes.
Flexbox Generator
Builds flexbox layouts visually, for the container and each item.
CSS Loader Generator
Creates pure CSS loading spinners and animations with no images or JavaScript.
CSS Filter Generator
Builds CSS filter effects on a sample image and copies the filter CSS.
CSS Transform Generator
Builds 2D and 3D CSS transforms with a live preview.
Scrollbar Generator
Generates custom scrollbar CSS for all browsers, standard and WebKit.
HTML Table Generator
Turns a grid or pasted spreadsheet data into accessible HTML table code.
HTML Live Preview
Runs HTML, CSS, and JavaScript live in a secure sandbox with a console.
Meta Redirect Generator
Builds a meta refresh redirect page with a JavaScript fallback and a visible link.
QR Code Generator
Creates QR codes for links, Wi-Fi, contacts, and more, as PNG or SVG.
QR Code Scanner
Reads QR codes from images, pasted screenshots, or the camera, in the browser.
Barcode Generator
Makes Code 128, EAN, UPC, Code 39, and ITF-14 barcodes with check digits.
Credit Card Validator
Checks card number format: Luhn checksum, brand, and length.
Test Card Number Generator
Generates format-valid test card numbers and lists official sandbox test cards.
Lorem Ipsum Generator
Generates lorem ipsum paragraphs, sentences, words, or list items as text or HTML.
Google SERP Preview
Previews how a title and meta description may appear in Google results.
JSON, XML, and YAML
- JSON Formatter, JSON Validator, and JSON Viewer tidy, check, and explore JSON. The JSON Schema Validator checks data against a schema.
- XML Formatter and XML Validator do the same for XML, and the YAML Validator catches indentation mistakes in config files.
- Convert between formats with XML to JSON, JSON to XML, XML to YAML, YAML to XML, and HTML to YAML. The JSON to CSV and JSON to YAML converters live under Converters.
- Check API descriptions with the OpenAPI Validator.
Formatting and minifying code
Beautify code with the HTML, CSS, JavaScript, SQL, PHP, and GraphQL formatters. Shrink files for production with the CSS Minifier and JavaScript Minifier, and compare two versions with the Diff Checker. Markdown Preview renders documentation as you write it.
Encoding, security, and identifiers
URL encoding, Base64, and HTML entities can be reversed. A hash can't, which is why it is used to check that data hasn't changed. The JWT Decoder reads and verifies tokens, the Password Generator creates strong secrets, and the Htpasswd Generator hashes Basic Auth passwords. For IDs and time, use the UUID Generator and Unix Timestamp Converter.
Keys, secrets, and authentication
Sign and check API messages with the HMAC Generator, hash passwords with the Bcrypt Generator, and create key pairs with the RSA Key Generator. The Basic Auth Header Generator and TOTP Generator help when you set up logins and two-factor codes. For config secrets there are the Random Token, WordPress Salt, and Blowfish Secret generators, and the Password Strength Checker tells you how long a password would hold up.
CSS and HTML generators
Build CSS visually and copy the code: gradients, box shadows, text shadows, border radius, flexbox layouts, loaders, filters, transforms, and scrollbars. For markup, the HTML Table Generator writes accessible tables and the HTML Live Preview runs a snippet safely in a sandbox.
Codes and test data
Make QR codes and barcodes, or read a QR code from a screenshot with the QR Code Scanner. To test payment forms, check numbers with the Credit Card Validator and get test card numbers that pass format checks. The Lorem Ipsum Generator fills a layout with placeholder text.
Testing and command-line helpers
- Regex Tester highlights matches and groups as you type.
- Cron Expression Parser explains a schedule and lists the next runs.
- cURL Command Builder, Sed Command Generator, and Sed Command Validator write and check shell commands.
- Printf Tester and PHP Serialize / Unserialize help with PHP and C strings.
Web server and site setup
Write Apache rules with the .htaccess Redirect Generator and check them with the .htaccess Validator. Control crawlers with the Robots.txt Generator, make a site installable with the Web App Manifest Generator, and start front-end work with the Color Converter, HTML Form Generator, and SQL Query Generator.
The URL Parser splits a link into its parts, the MIME Type Lookup gives the right Content-Type for a file, the Meta Redirect Generator covers hosts without server redirects, and the SERP Preview shows how a title and description may look in Google.
Frequently asked questions
Is my data sent to a server?
No. All developer tools run in your browser. A few tools download a library the first time you use them, such as the SQL formatter or Terser, but your input never leaves your device.
What is the difference between encoding and hashing?
Encoding, such as Base64 or URL encoding, can be reversed to get the original data back. A hash can't be reversed. It is used to check that data hasn't changed.
Do these tools need a server to test my requests?
No. Generators such as the cURL builder and the .htaccess generator only write text for you to run or upload. They never contact your server.
Are the generated keys and secrets safe to use?
They are created in your browser with the Web Crypto random number generator and are never sent or stored. For production servers, many teams still generate keys on the machine that uses them.
Can I use these tools for commercial work?
Yes. The tools are free to use for any purpose.