04Category
Developer tools
Formatters, encoders, decoders, generators and references.
Featured
Popular
- JSON FormatterBeautify or minify JSON with your indentation
- UUID GeneratorGenerate UUID v4 and time-ordered v7 IDs
- Base64 EncoderEncode text or files as Base64 and data URLs
- Timestamp ConverterUnix time, ISO 8601 and time zones
- Color PickerPick and convert HEX, RGB, HSL, HSV and OKLCH
- Mock Data GeneratorSynthetic users, orders and more — JSON, CSV, SQL or TypeScript
- Contrast CheckerWCAG 2 contrast ratio for text and UI
- URL CleanerStrip utm_, fbclid, gclid and other tracking from links
All Developer tools
- Text
Regex Tester
Live matching, capture groups and replace
Regex Patterns
Ready-made patterns for emails, URLs, dates and more
- Text · JSON
Diff Checker
Compare text, JSON or code side by side
JWT Decoder
Decode header and claims, verify HMAC signatures
Base64 Encoder
Encode text or files as Base64 and data URLs
- Text
Base64 Decoder
Decode Base64 back to text or a file
- Text
URL Encoder
Percent-encode text and parse query strings
- Text
URL Decoder
Decode percent-encoded URLs and parameters
- Text · HTML
HTML Encoder
Escape text as HTML entities
- Text · HTML
HTML Decoder
Turn & and ' back into characters
Hash Generator
SHA-1, SHA-256, SHA-384, SHA-512 and HMAC
UUID Generator
Generate UUID v4 and time-ordered v7 IDs
Nano ID Generator
Short, URL-safe random IDs with custom alphabets
Timestamp Converter
Unix time, ISO 8601 and time zones
- SQL
SQL Formatter
Format and highlight SQL for many dialects
- SQL
SQL Minifier
Collapse SQL onto a single line
- YAML
YAML Formatter
Validate and format YAML, convert to JSON
- YAML · JSON
YAML ⇄ JSON
Convert between YAML and JSON both ways
- XML
XML Formatter
Pretty-print, minify and validate XML
- XML
XML Validator
Check that XML is well-formed
Cron Expression Helper
Explain cron schedules and preview next runs
HTTP Status Codes
Every status code with meaning and usage
MIME Type Lookup
Find the MIME type for an extension, or the reverse
User-Agent Inspector
Parse browser, engine, OS and device from a UA string
Browser Info
Screen, features and capabilities of this browser
Keyboard Inspector
See key, code and modifiers for any keypress, plus app shortcuts
- Text
Hex Encoder
Text to hexadecimal UTF-8 bytes
- Text
Hex Decoder
Hexadecimal bytes back to text
- Text
Text ⇄ Binary
Text to 8-bit binary and back
- Text
Text ⇄ ASCII Codes
Characters to decimal byte values and back
- Text
Text ⇄ Octal
Characters to octal byte values
- Text
Unicode Escape Converter
Text ⇄ \u escapes, code points and back
- Text
Text ⇄ Unicode Code Points
U+0041 notation for every character
- Text
Base32 Encode / Decode
RFC 4648 Base32 (used by TOTP secrets)
- Text
ROT13
The classic letter-rotation cipher
- Text
Morse Code Translator
Text ⇄ Morse code
- Text
Unicode Character Inspector
Code point, UTF-8/16 bytes and type of every character
- JSON
JSON Minifier
Remove whitespace and see the size saved
- JSON
JSON Sort Keys
Alphabetize keys at every level
- JSON
JSON Flatten
Nested objects to dot-path keys
- JSON
JSON Unflatten
Dot-path keys back to nested JSON
- JSON
JSON Escape
Turn text into a JSON string literal
- JSON
JSON Unescape
Turn a JSON string literal back into text
- JSON
JSONPath Tester
Query JSON with $.store.book[*].title and filters
- JSON
JSON to TypeScript
Generate interfaces from a JSON sample
- Text
URL Parser
Break a URL into protocol, host, path, query and fragment
URL Cleaner
Strip utm_, fbclid, gclid and other tracking from links
UTM Cleaner
Remove UTM campaign parameters from a link
Query String Builder
Build properly encoded ?key=value strings
Query String Parser
See every parameter in a URL, decoded
UTM Link Builder
Campaign URLs with utm_source, medium and campaign
HTTP Client
Send GET, POST, PUT, PATCH and DELETE requests from your browser
cURL Converter
Turn a cURL command into fetch, Axios, Python, Go or PHP
cURL Generator
Build a cURL command from a request form
fetch() Code Generator
JavaScript fetch code for any request
Axios Code Generator
Axios request code for any request
HTTPie Command Generator
HTTPie commands for any request
HTTP Headers Reference
What every common request and response header does
Git Command Reference
Everyday git commands, with undo recipes
ASCII Table
All 128 ASCII characters with decimal, hex, octal and binary
Gitignore Generator
Combine templates for Node, Python, Go, Rust, Next.js, IDEs and OSes
Conventional Commit Builder
Well-formed commit messages with type, scope and breaking changes
Git Branch Name Generator
Clean branch names from a ticket and description
SemVer Calculator
Parse, compare and bump versions; check npm ranges
SemVer Parser
Major, minor, patch, pre-release and build parts
GitHub URL Parser
Owner, repo, branch and path — plus raw, clone and ZIP links
- CSV
CSV to SQL INSERT
INSERT statements (and CREATE TABLE) from CSV
- JSON
JSON to SQL INSERT
INSERT statements from an array of JSON objects
SQL INSERT Generator
Batch INSERTs for PostgreSQL, MySQL, SQLite and SQL Server
SQL IN Clause Generator
Turn a list of values into IN (…)
Mock Data Generator
Synthetic users, orders and more — JSON, CSV, SQL or TypeScript
Mock JSON Generator
Synthetic JSON records from a schema
Mock CSV Generator
Synthetic CSV datasets from a schema
- HTML
HTML Formatter
Beautify HTML with consistent indentation
- HTML
HTML Minifier
Remove whitespace and comments from HTML
CSS Formatter
Beautify CSS rules and media queries
CSS Minifier
Smaller CSS with strings and comments handled safely
HTML / CSS / JS Playground
Write code and see it run in a locked-down sandbox
CSS Playground
Try CSS against live HTML
JavaScript Playground
Run JavaScript with a console — no network access
Regex Escape
Escape special characters so text matches literally
Regex Splitter
Split text on a regular expression
Regex Match Extractor
Pull every match or capture group into a list
JWT Generator / Signer
Sign JWTs with HS256, RS256, PS256, ES256 or EdDSA
Subnet / CIDR Calculator
Network, broadcast, host range and mask for any IPv4 CIDR
Subnet Splitter
Divide a network into equal smaller subnets
IP Range to CIDR
The smallest set of CIDR blocks covering a range
IPv6 Calculator
Compress, expand and analyse IPv6 addresses and prefixes
IP Address Converter
IPv4 as integer, hex, binary and IPv4-mapped IPv6
chmod Calculator
Unix permissions: checkboxes, octal, symbolic and umask
- Text
Code to Image
Beautiful highlighted code screenshots for slides and posts
- Image · SVG
Favicon Generator
favicon.ico, PNG favicons, Apple touch and PWA icons from a logo or letter
- Image · SVG
App Icon Generator
Every iOS and Android launcher icon size from one image
- Image
Sprite Sheet Generator
Pack icons or frames into one PNG with CSS and JSON
Placeholder Image Generator
Dummy images of any size as PNG, JPG, WebP or SVG
- Image
Image to Base64
Encode an image as a Base64 data URI for HTML or CSS
- HTML
HTML to PDF
Print sanitized HTML as a PDF via your browser
- JSON
JSON Studio
Format, validate, explore and convert JSON
- JSON
JSON Formatter
Beautify or minify JSON with your indentation
- JSON
JSON Validator
Find syntax errors with exact line and column
- JSON
JSON Viewer
Collapsible tree view for large documents
- JSON
JSON Schema Generator
Infer a JSON Schema from sample data
- JSON
JSON Diff
Compare two JSON documents, key order ignored
Unix Timestamp
Current epoch time and conversions
- Text
camelCase
Convert text to camelCase
- Text
PascalCase
Convert text to PascalCase
- Text
snake_case
Convert text to snake_case
- Text
kebab-case
Convert text to kebab-case
- Text
Slug Generator
Turn titles into clean URL slugs
- Text
Whitespace Visualizer
Reveal tabs, NBSPs and invisible characters
- Text
CONSTANT_CASE
Convert text to CONSTANT_CASE
- Text
dot.case
Convert text to dot.case
- Text
path/case
Convert text to path/case
- Text
lowercase
Convert text to lowercase
- Text
UPPERCASE
Convert text to UPPERCASE
- Text
Title Case
Convert text to Title Case
- Text
Sentence case
Convert text to Sentence case
Color Picker
Pick and convert HEX, RGB, HSL, HSV and OKLCH
Contrast Checker
WCAG 2 contrast ratio for text and UI
CSS clamp() Generator
Fluid font sizes and spacing between two viewport widths
Hex Viewer
Raw bytes of any file in hex and ASCII, with search and an inspector
px ⇄ rem / em Converter
Pixels to rem and em (and back) for any root size
Viewport Unit Calculator
vw, vh, vmin and vmax to pixels
8px Grid Calculator
Snap sizes to an 8-point (or any) grid
Golden Ratio Calculator
Split a size by φ and build a golden type scale
Number Base Converter
Binary, octal, decimal, hex and any base 2–36 — any size
Random String Generator
Random strings from any character set
Secret Key Generator
256-bit keys as hex, Base64 or Base64URL
File Hash / Checksum
SHA-256, SHA-384, SHA-512 and SHA-1 of any file — verify downloads
2FA Code Generator (TOTP)
Live authenticator codes from a secret or otpauth:// link, plus setup QR codes
Key Pair Generator
Ed25519, RSA and ECDSA keys as OpenSSH, PEM and JWK
SSH Key Generator
id_ed25519 / id_rsa key pairs ready for ~/.ssh and GitHub
RSA Key Generator
2048–4096-bit RSA keys in PEM (SPKI / PKCS#8)
- Image
Open Graph Image (1200×630)
Link-preview images for websites and blogs