Pele

Pele is an open source rendering library focused on one job: turning Mermaid diagram syntax into SVG. Rather than shipping a full diagramming framework, it takes the text you already write in Mermaid and outputs clean SVG markup, which keeps the integration surface small and the output easy to style or embed.

The project emphasizes efficiency. Its documentation compares Pele with Mermaid.js on bundle size and render time, reporting a gzipped bundle of roughly 230 kB against 1.6 MB, and render times from 0.05 to 0.3 ms versus 6 to 82 ms. It lists zero direct dependencies and states support for every diagram type built into Mermaid 12.1.0.

Theming is handled through CSS variables such as background, foreground, line, surface, and border colors. Because colors and fonts are set in CSS, changes apply without re-rendering the diagram, which simplifies dark mode and brand styling. On small screens, Pele adapts the layout rather than scaling the diagram down.

The site includes a playground for editing Mermaid syntax and seeing the SVG output, plus documentation covering how it works, API, theming, compatibility, and security. Developers building dashboards, documentation sites, or internal tools that need embedded diagrams are the natural audience.

To evaluate it, start with the playground using a diagram from your own project, then check the compatibility and security pages before adopting it. Pele is a focused, performance-oriented alternative for teams that want Mermaid synta