Free Developer Tools
Format JSON, test regular expressions, decode tokens and generate test data for your next development task.
22 tools · no sign-up · free to use
JSON Formatter
Pretty-print, minify and validate JSON, with parse errors located by line and column. In your browser, no upload.
Open free tool →Base64 Encoder / Decoder
Encode text or files to Base64, turn images into data URIs with CSS and <img> snippets, and decode Base64 back to a previewable file. Nothing leaves your browser.
Open free tool →Regex Tester
Test a regular expression against sample text with live match highlighting, capture groups and replace preview. Free, in your browser.
Open free tool →JWT Decoder
Decode a JWT's header and payload, read the expiry in plain language, verify HS, RS, PS and ES signatures, or sign a new token. Nothing leaves your browser.
Open free tool →Cron Expression Generator
Build a cron schedule from dropdowns or paste one, read it in plain English, and see the next 10 run times in your zone and UTC. Free, in your browser.
Open free tool →Lorem Ipsum Generator
Generate lorem ipsum or readable English dummy text by paragraphs, sentences or words, as plain text, HTML or Markdown.
Open free tool →Dummy Text Generator
Click 1 to 10 and the paragraphs are on your clipboard. Lorem ipsum, English, German, French or Spanish.
Open free tool →Unix Timestamp Converter
Convert epoch seconds, milliseconds, microseconds or nanoseconds to dates in any time zone, and back. Live clock, batch mode, code snippets.
Open free tool →UUID Generator
Generate UUID v4 or time-ordered v7, ULIDs and NanoIDs in bulk, or paste an ID to see its version and embedded timestamp.
Open free tool →URL Encoder / Decoder
Percent-encode or decode text for URLs in component, full-URL or form mode, and edit a URL's query parameters in a table.
Open free tool →HTML Entity Encoder
Escape text for HTML with named or numeric entities, decode &-style references back to characters, and search an entity reference table.
Open free tool →Number Base Converter
Convert integers of any size between binary, octal, decimal, hex, base 32, base 36 and any base 2–36, with a two's complement view.
Open free tool →SQL Formatter
Format messy SQL into readable, consistently indented queries for PostgreSQL, MySQL, T-SQL, BigQuery and more. Runs in your browser.
Open free tool →JSON to TypeScript
Paste a JSON sample and get TypeScript interfaces, a Zod schema, JSON Schema or types for Go, Python, Java, C#, Kotlin, Swift and Rust.
Open free tool →curl to Code
Paste a curl command, including Chrome "Copy as cURL", and get the same request in Python, JavaScript, Node, Go, PHP, Ruby, Java, C#, wget or HTTPie.
Open free tool →YAML Validator
Validate YAML with the exact line and column of each error, and catch the mistakes parsers accept silently: yes/no booleans, tabs, duplicate keys.
Open free tool →HTTP Status Codes
Every official HTTP status code from 100 to 511, plus nginx, Cloudflare and AWS codes, with when to use each.
Open free tool →User Agent Parser
See your own user agent and client hints, or parse any UA string into browser, engine, OS, device and CPU. Bulk mode with CSV.
Open free tool →Chmod Calculator
Tick read, write and execute boxes to get the octal mode and chmod command, or decode 755, 644 and rwxr-xr-x.
Open free tool →.gitignore Generator
Combine .gitignore templates for languages, frameworks, editors and operating systems into one clean file.
Open free tool →Subnet Calculator
Network, broadcast, host range and mask for any CIDR; split networks with VLSM, expand IPv6 and find overlapping ranges.
Open free tool →Docker Run ⇄ Compose
Turn a docker run command into a docker-compose.yml service, or a Compose service back into docker run.
Open free tool →