Developer tools that just work
A growing library of free, browser-based utilities for developers. No account, no tracking, no bloat — open a tool and get to work.
JSON / YAML Formatter
Format, validate, and diff JSON or YAML. Instantly spot syntax errors and beautify payloads.
Regex Tester
Test regular expressions with live match highlighting and capture group inspection.
Cron Expression Builder
Build and validate cron expressions with a human-readable schedule preview.
Unix Time Converter
View the current Unix timestamp live and convert between Unix timestamps and human-readable dates.
Base64 Encoder/Decoder
Encode plain text to Base64 or decode Base64 back to text. Supports standard and URL-safe variants.
JWT Decoder
Decode JSON Web Tokens to inspect headers, payload claims, and expiry status.
URL Encoder/Decoder
Percent-encode or decode URLs and URL components. Parse a URL into its individual parts.
Text Diff Checker
Compare two texts line by line. Added lines highlighted green, removed lines red.
Color Converter
Convert colors between HEX, RGB, and HSL formats with a live color swatch.
UUID Generator
Generate cryptographically random UUID v4 identifiers one at a time or in bulk.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text input.
User Agent Parser
Paste any User Agent string to identify the browser, OS, device type, and rendering engine.
iFrame Tester
Preview any URL inside an iFrame with configurable dimensions and sandbox settings.
DNS Propagation Checker
Check DNS records across multiple global resolvers and verify propagation status.
SSL Certificate Checker
Inspect SSL/TLS certificates — expiry, issuer, chain validity, and cipher details.
About Dev-Utilities
Dev-Utilities is a collection of free developer utilities that run entirely in your browser. Every tool is designed to be fast, focused, and reliable — no unnecessary features, no sign-up walls, no ads cluttering your workflow.
Client-side tools like the JSON formatter and regex tester execute entirely in your browser using JavaScript — your data never leaves your machine. Server-side tools like the DNS propagation checker and SSL certificate inspector make server requests on your behalf, letting you bypass browser restrictions and get accurate results from multiple global vantage points.
The site is open for use by anyone — from junior developers learning the ropes to senior engineers who just need a quick utility during an incident. Bookmark the tools you use most and they will always be here, fast and free.