Developer
Gauntlet Loop Prompt Generator
Builder/critic agent prompts with brakes built in
FREEOpen tool
Essential developer utilities: JSON formatter, regex playground, SQL formatter, JWT decoder, Base64 encoder, UUID generator, diff checker, and more.
Every developer needs a reliable set of online utilities. Our developer tools handle the everyday tasks — formatting JSON, testing regex patterns, decoding JWTs, converting cURL commands to code, and more.
All tools run entirely in your browser with zero server communication. Your code, API keys, and data never leave your device. No accounts, no tracking, no limits.
Builder/critic agent prompts with brakes built in
Format, validate & diff JSON — runs entirely in browser
Test regex live — railroad diagrams + plain English explained
Beautify and format SQL queries instantly
Decode JWT header, payload & expiry — tokens stay private
Encode and decode Base64 instantly
Generate unique IDs with one click
MD5, SHA-1, SHA-256, SHA-512 hashes in your browser
Compare two texts and spot every difference instantly
Convert cURL commands to Python, JavaScript, Go, and PHP
Validate, compare, and convert .env files
Format, validate and minify XML with syntax highlighting
Convert timestamps to human dates and back
Build cron jobs visually — no syntax to memorize
Write Markdown with instant live preview and HTML export
Compare AI API costs across every major LLM
Count tokens & estimate costs for GPT-5.4, Claude 4.6 & Gemini 3.1 Pro
Visualize project dependencies as an interactive graph