Chart.js
What it is: Simple JavaScript charting library. Canvas-based, responsive, animated charts.
What It Does Best
Easy to start. Import one file, 10 lines of code, you have a working chart.
Responsive by default. Charts resize automatically. Mobile-friendly out of the box.
Smooth animations. Entrance animations, hover effects built-in. Looks modern without effort.
Pricing
Free. Open source, MIT license.
When to Use It
✅ Web apps need standard charts (bar, line, pie)
✅ Want something working in minutes
✅ Team doesn't know D3.js
✅ Dashboards with common chart types
When NOT to Use It
❌ Need custom, unique visualizations (D3.js better)
❌ Complex interactions beyond basic hover (D3.js better)
❌ Very large datasets (canvas performance limits)
Bottom line: D3.js without the learning curve. Perfect for 80% of web charting needs. Quick, pretty, and simple.