Developer Tools Guides & Tutorials
Articles, guides and tutorials about developer tools - JSON, Base64, hashing and developer utilities. Featured reading: UUID vs GUID: Generate Version 4 IDs Online (When to Use Which); Common Regex Patterns You Can Test Online (Email, URL, Phone); JSON Schema Validator in your browser, no signup; Free Regex Tester With Live Match Highlighting.
UUID vs GUID: Generate Version 4 IDs Online (When to Use Which)
UUID and GUID are the same 128-bit identifier. When to use v4, what is not a unique ID, and a free in-browser generator.
Common Regex Patterns You Can Test Online (Email, URL, Phone)
Test email, URL, phone and whitespace regex against real samples before production. Live highlighting, no paste-into-a-black-box.
JSON Schema Validator in your browser, no signup
JSON on its own carries no rules. Free in your browser, no account needed.
Free Regex Tester With Live Match Highlighting
Write and test regular expressions with instant, color-coded match highlighting, no more guessing why a pattern silently fails.
CSS Box Shadow Generator: what it does and how to use it
Visually design a CSS box-shadow - adjusting offset, blur, spread, color, and opacity with live preview - and generates the exact CSS syntax to copy, rather
URL Parser in your browser, no signup
A URL packs six distinct pieces of information into one string, and when it is long enough to wrap across three lines nobody can read it accurately.
SQL Query Generator in your browser, no signup
Building a query through a form rather than typing it removes the syntax errors and, more usefully, the structural ones.
How to use API Tester online, free
Build and send HTTP requests (GET, POST, PUT, DELETE, etc.) with custom headers, query parameters, and a request body, then inspect the full response -
JSON Formatter for Developers: Debug API Responses Fast
Pretty-print a minified API payload, find the missing comma, and minify again for production. Browser JSON formatter for debugging, not a generic intro.
How to use JSON Compare online, free
Comparing JSON with an ordinary text diff produces a lot of noise. Free in your browser, no account needed.
SQL Formatter Online Free: Beautify Queries Instantly
Pretty-print messy SQL with clear indentation - free SQL formatter for debugging and reviews.
Mock Data Generator in your browser, no signup
Generate realistic-looking fake data - names, emails, addresses, and more - as CSV or JSON, useful for populating a test database, demoing an application