Development — entry 057 of 100
Kroki
Kroki puts a single unified HTTP API in front of two dozen open-source diagram-as-code renderers, including PlantUML, Mermaid, GraphViz, D2, BPMN, Excalidraw, and WaveDrom, so callers send diagram source text and get back an image with no local toolchain to install. A GET request embeds the (deflate+base64-encoded) diagram directly in the URL, making it trivial to drop live diagrams straight into Markdown or HTML. The project and its public instance at kroki.io are free and open source, with self-hosting via Docker documented for anyone who needs a private instance.
AuthenticationNone requiredCall it straight away — no key, no signup.
HTTPSSupportedTraffic is encrypted in transit.
CORSEnabledCallable directly from browser JavaScript.
PricingFreeNo paid tier — free for the documented use case.
FormatsSVG, PNG, PDF, JPEGResponses can be requested as SVG or PNG or PDF or JPEG.
GreatAPIs Score
Score94
Authentication25/25No authentication required
Pricing20/20Free to use
Docs14/20Documentation URL provided
Formats15/15Supports 4 response formats
Freshness20/20Verified within 6 months
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<a href="https://greatapis.com/api/kroki/"><img src="https://greatapis.com/badge/kroki.svg" alt="Scored 94 on greatapis.com"></a>Auth quickstart
- No key needed — call it now.
Stored keyNo key stored
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.