Kroki
FreeLiveLast verified 24 Sept 2026
Renders 30+ text-based diagram formats (PlantUML, Mermaid, GraphViz, BPMN...) as SVG or PNG, no key.
Example request
curl -s 'https://kroki.io/plantuml/svg/eNplj70OwjAMhPc8hdUJBsKPxAJtJJhYeAaUgkERiVPVEQgQ705aKkhhu4v95c58NlTpWjuoNZ0ZK5hNBH8eD5WB6Wwucg43i0oA1LgPmk4W4REdwMbX5u4paLuy5kQOKSzA4jEs4_gp8nFHii-YbbWhrOUHLkp5MXgdNo5NsxA8DcUzBdaasQPKKOXeu8pTjGqpvnP-gPaHz0vVBgXOx6XKQDM0fhdYiAQHKdV_QrcJRaF6fRMNo5Hq9Uhnsv01OS3REWzId-cX0lF_aA=='
Free tier, in plain English
No key needed and no published rate limit on the hosted service; the code can also be self-hosted.
Alternatives in Charts
Diagrams.soTurns natural-language prompts into editable cloud-architecture diagrams (draw.io XML/SVG).FreemiumImage-ChartsRenders pie, bar, line and QR-code charts as PNG images from a single GET URL.Freemiummermaid.inkRenders Mermaid flowcharts, sequence and Gantt diagrams from a URL to SVG, PNG/JPEG/WebP or PDF.FreeQuickChartRenders Chart.js configs, QR codes and other visualizations as static images from a URL.FreemiumWord Cloud APIGenerates a word-cloud image (base64) from submitted text, with size, color, and stop-word options.
All 6 Charts APIs →