Developer Tools
The core developer toolbox on UtilityBoxHub: 19 fast, dependable utilities for everyday development work — formatting and validating JSON, XML, YAML, SQL, and Markdown; decoding and generating JWTs; testing regex; building and parsing cron schedules; converting Base64, URLs, HTML entities, and timestamps; generating hashes and UUIDs. Every one of them runs entirely in your browser, so nothing you paste — API responses, tokens, secrets, or anything else — is ever uploaded anywhere.
JSON Formatter & Validator
Format, minify, and validate JSON instantly in your browser.
XML Formatter & Validator
Format and validate XML instantly in your browser.
YAML Formatter & Validator
Format, validate, and convert YAML to JSON instantly.
Regex Tester
Test regular expressions with live-highlighted matches and groups.
Markdown to HTML Preview
Preview Markdown as rendered HTML, with a raw HTML view you can copy.
JSON to Python Converter
Generate Python dataclasses from a JSON sample, with types inferred automatically.
JWT Decoder
Decode a JWT's header, payload, and expiry status instantly.
SQL Formatter
Format and beautify SQL queries with Standard SQL, MySQL, and PostgreSQL support.
Cron Expression Parser
Explain a cron expression in plain English and see its next 5 run times.
JSON to TypeScript Converter
Generate TypeScript interfaces from a JSON sample, with types inferred automatically.
cURL to Python/JavaScript Converter
Convert a cURL command into equivalent Python (requests) or JavaScript (fetch) code.
JWT Generator
Build and sign a JWT from a custom header, payload, and secret using HS256.
Cron Expression Generator
Build a valid cron expression using simple field pickers, with a plain-English preview.
Base64 Encode/Decode
Encode text to Base64 or decode Base64 back to text.
URL Encoder/Decoder
Encode text for URLs or decode URL-encoded text back to plain text.
HTML Entity Encoder/Decoder
Encode text to HTML entities or decode HTML entities back to plain text.
Unix Timestamp Converter
Convert between a Unix timestamp and a human-readable date, in local time and UTC.
Hash Generator (MD5, SHA-1, SHA-256, SHA-512)
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text.
UUID/GUID Generator
Generate random UUID v4 / GUID values, one at a time or in bulk.