HTML Tools

Build single-file applications combining HTML, CSS, and JavaScript that deliver useful functionality without build steps, frameworks, or servers.

Based on Simon Willison's patterns from building 150+ such tools.

When to Use

• "Build me a tool that..."
• "Create a simple app to..."
• "Make a utility for..."
• Client-side data processing or visualization
• Tools that should work offline or be easily shared
• Prototypes that need to ship fast

When to Skip