Free developer tools
Small, fast tools for working with APIs. They run entirely in your browser: no sign-up, and nothing you paste leaves your machine.
JSON Formatter & Validator
Beautify, validate and minify JSON, with exact error locations.
Open tool →Unix Timestamp Converter
Convert epoch time to a date and back, in any time zone.
Open tool →AI Tool & MCP Server Generator
Turn any API request into an OpenAI or Claude tool definition, or an MCP server.
Open tool →JSON Schema Generator
Create a JSON Schema from any JSON sample, with formats and required fields.
Open tool →JSON to TypeScript & Zod
Generate TypeScript types or a Zod schema from any JSON sample.
Open tool →JWT Decoder
Decode JWT tokens, explain every claim and verify signatures.
Open tool →UUID Generator
Generate random UUID v4 or time-ordered v7 IDs in bulk, and inspect any UUID.
Open tool →Base64 Encoder & Decoder
Encode and decode Base64 and Base64URL text, files and images.
Open tool →Cron Expression Explainer
Translate cron schedules into plain English and see the next run times.
Open tool →cURL Converter
Turn curl commands into Python, JavaScript, Go, PHP or Ruby code.
Open tool →Convert curl to your language
Debugging an error? See what every HTTP status code means. Looking for data to work with? Browse free APIs that need no key.