FormatCalc library
Developer tools
without the noise.
Free developer tools from FormatCalc. Fast, private, and processed entirely in your browser. Choose a tool below to get started—no account or upload required.
Unix Timestamp Converter
Convert Unix timestamps to readable dates and back.
UUID Generator
Generate unique UUIDs instantly.
SHA-256 Hash Generator
Create a SHA-256 hash from any text.
JWT Decode
Decode a JSON Web Token header and payload without sending it anywhere.
JWT Header to JSON
Extract and format the header from a JSON Web Token.
JWT Payload to JSON
Extract and format the payload claims from a JSON Web Token.
JSON to TypeScript Interface
Generate TypeScript interfaces from a JSON object or array.
JSON to Zod Schema
Generate a Zod validation schema from JSON data.
JSON to GraphQL Type
Generate GraphQL type definitions from a JSON object.
JSON to Go Struct
Generate Go struct definitions and JSON tags from JSON.
JSON to Python Dataclass
Generate Python dataclasses with type annotations from JSON.
JSON to Java Class
Generate Java classes with fields from JSON data.
JSON to C# Class
Generate C# classes and JSON property names from JSON.
JSON to PHP Array
Convert JSON data into a ready-to-use PHP array.
JSON to JavaScript Object
Turn JSON into a formatted JavaScript object declaration.
JavaScript Object to JSON
Convert a simple JavaScript object literal into valid JSON.
cURL to Fetch
Convert a cURL request into the browser Fetch API.
cURL to Axios
Convert a cURL request into an Axios request.
cURL to Python Requests
Convert a cURL request into Python requests code.
cURL to Node.js
Convert a cURL request into modern Node.js Fetch code.
HTTP Headers to JSON
Convert raw HTTP headers into a JSON object.
JSON to HTTP Headers
Convert a JSON object into HTTP header lines.
Query String to JSON
Convert URL query parameters into a JSON object.
JSON to Query String
Convert a JSON object into a URL-encoded query string.
URL Parser
Extract the protocol, host, path, query, and hash from a URL.
OpenAPI YAML to JSON
Convert an OpenAPI YAML document into formatted JSON.
OpenAPI JSON to YAML
Convert an OpenAPI JSON document into readable YAML.
GraphQL Query Formatter
Format a GraphQL query or mutation for easier reading.
Regex Escape/Unescape
See escaped and unescaped forms of regular-expression text.
Cron Expression to Human Text
Explain a five-field cron expression in plain English.
Human Text to Cron Expression
Turn common scheduling phrases into five-field cron expressions.
Docker Compose YAML to JSON
Convert Docker Compose YAML into formatted JSON.
Kubernetes YAML to JSON
Convert Kubernetes YAML manifests into formatted JSON.
JSON to Kubernetes YAML
Convert a Kubernetes JSON manifest into readable YAML.
Regex Tester
Test a JavaScript regular expression against sample text.
Lorem Ipsum Generator
Generate placeholder copy for layouts and prototypes.
Color Converter
Convert HEX, RGB, and HSL colors into a practical palette.