Developer Tools
Data formats, code formatting, encoding, and generators - 58 tools
XML to JSON
XML to JSON, attributes kept as @_ keys
JSON to XML
JSON to indented XML under a root element
TSV to CSV
Tab-separated text to CSV, quoted where needed
CSV to TSV
Comma, semicolon, or pipe CSV to tab-separated text
Excel to JSON
XLSX, XLS, or ODS sheets to JSON objects
Excel to CSV
One CSV per sheet of an XLSX, XLS, or ODS file
CSV to Excel
Build an .xlsx or .xls workbook from CSV
TOML to JSON
Parse TOML into indented JSON
JSON to TOML
Write a JSON object as TOML tables
JSON Formatter
Validate JSON and indent it, keys sorted on request
JSON Minifier
Validate JSON and strip its whitespace
UUID Generator
Up to 1,000 UUIDs, version 4 or version 7
Lorem Ipsum Generator
Placeholder text by paragraphs, sentences, or words
Base64 Encode and Decode
Text to Base64 or URL-safe Base64, and back
URL Encoder
Percent-encode a value or a full URL, and decode
Hash Generator
MD5, SHA, CRC32 for text and files
Password Generator
Random passwords or EFF word passphrases
CSV to JSON
CSV to objects, arrays, or JSON Lines
JSON to CSV
JSON array to CSV, nested keys as dotted columns
CSS Formatter
Format or minify CSS
HTML Formatter
Re-indent HTML with its inline CSS and scripts
JS Minifier
Minify JavaScript with Terser
JavaScript Formatter
Format with js-beautify or minify with Terser
SCSS to CSS
SCSS to expanded or compressed CSS
TypeScript to JavaScript
TypeScript in, plain JavaScript out, enums converted
XML Formatter
Check that XML is well-formed and indent it
SQL Formatter
Format SQL in one of 12 dialects
Regex Tester
Test a JavaScript regex: matches, groups, replace
Markdown Previewer
See Markdown rendered as you type
Markdown to HTML
Markdown to a complete HTML5 document
JWT Decoder
Decode a JWT and verify its signature
Markdown Editor
Write Markdown, download the .md and .html
API Tester
Send GET, POST, PUT, PATCH, or DELETE requests
Number Base Converter
Bases 2 to 36, fractions and signs included
YAML to JSON
YAML to JSON; several documents become an array
JSON to YAML
JSON to block-style YAML
Color Picker
Pick a color and read its HEX and RGB values
Unix Timestamp Converter
Unix time in s, ms, µs, or ns to dates and back
Aspect Ratio Calculator
Simplify a ratio and compute the missing side
URL Parser
Split a URL into its parts and query parameters
HTML Encoder
Escape HTML special characters, decode entities
HTML Entity Decoder
Decode named and numeric HTML entities
Unicode Converter
Text to UTF-16 escape sequences and back
Hex to Text
Text to UTF-8 bytes in hex, and back
JSON to TypeScript
TypeScript interfaces from a JSON sample
JSON to Go Struct
Go structs with json tags from a JSON sample
JSON to Rust Struct
Rust structs for serde from a JSON sample
JSON to Python Class
Python dataclasses from a JSON sample
JSON to PHP Class
A PHP array or typed PHP 8 classes from JSON
JSON to C# Class
C# classes with System.Text.Json attributes
CSV to SQL
CREATE TABLE and INSERT statements from CSV
SQL to CSV
Rows of INSERT statements to CSV
.env to JSON
.env lines to JSON and back, dotenv rules
Code Minifier
Minify JavaScript, TypeScript, CSS, or HTML
Diff Viewer
Line-by-line diff with changed words highlighted
Code Formatter
Format code in 13 languages
Cron Expression Explainer
Check a 5-field cron expression and its next runs
Cron Expression Builder
Build a cron expression from 8 presets
About Developer Tools
These tools transform text you paste, or a file you open, on the page itself, with libraries such as SheetJS for Excel, Terser for JavaScript, and Dart Sass for SCSS. The code and data you give them are not sent to our server. API Tester sends your request to the address you type, and Markdown Previewer and Markdown Editor let your browser load the pictures your Markdown links to, from their own hosts. The page covers data formats (JSON, XML, YAML, TOML, CSV, Excel), code formatting and minifying, encodings (Base64, URL, HTML, Unicode, hex), generators, and types from JSON for six languages.
How to use Developer Tools
- 1Find the tool by task: convert a data format, format or minify code, encode or decode, generate values, or inspect a token, URL, or timestamp.
- 2Paste your input or, where the tool offers it, open a file such as a CSV file or an Excel workbook.
- 3Correct the input if the tool reports an error: the JSON, XML, YAML, and TOML tools check that it parses before converting it.
- 4Copy the output or download it; Excel to CSV gives a ZIP with one CSV per sheet when the workbook has several.
Frequently asked questions
Is the code or data I paste sent anywhere?
No, with two exceptions: API Tester sends your request from your browser to the address you type, and the two Markdown previews let your browser fetch linked pictures from their hosts. If a tool shows an error or the page crashes, our error log receives the cleaned message, the tool name, and your browser's name and version, but never your pasted JSON or code.
Why does API Tester fail on an API that answers elsewhere?
The browser enforces CORS: when the API does not allow calls from other websites, your browser blocks the response, and API Tester cannot show it.
Which languages can I generate types for from JSON?
Six: TypeScript interfaces, Go structs, Rust structs for serde, Python dataclasses, PHP 8 classes, and C# classes. Each tool reads a JSON sample, and most make one type per nested object.
Are the generated passwords and UUIDs random?
Yes. Password Generator and UUID Generator draw their random values from crypto.getRandomValues, the browser's cryptographic random source, not from Math.random. A version 7 UUID also contains its creation time.
Tips and tricks
- ✓Paste a JSON response from API Tester into JSON to TypeScript to get matching interfaces.
- ✓Compare two versions of a config file in Diff Viewer; changed words inside a line are highlighted.
- ✓Unix Timestamp Converter guesses seconds, milliseconds, microseconds, or nanoseconds from the number of digits.
- ✓Choose UUID version 7 when the IDs should sort by creation time, version 4 when they should reveal nothing.