Plotly.js is a JavaScript charting library and interactive graphing framework used to create web-based visualizations. It functions as a high-performance data visualization engine that utilizes both SVG for static elements and WebGL for hardware-accelerated rendering of large datasets and complex 3D plots.
The library is distinguished by specialized toolkits for financial analysis, such as candlestick and OHLC charts, and geographic mapping tools for rendering choropleth and scatter maps with custom projections. It also supports complex scientific visualizations, including Sankey diagrams, parallel coordinates, and sunbursts.
The system provides comprehensive capabilities for user interaction, including zooming, panning, and frame-based data transition animations. It includes utilities for axis scaling, mathematical expression rendering, and the export of interactive plots into static image formats. To optimize web performance, the library allows for the generation of custom bundles containing only the specific chart modules and trace types required for a project.