Kroki

by kroki.io

Chart APIs Added on October 31st, 2026 Checked and working on November 1st, 2026

What it does

Kroki turns text diagram descriptions into images with one simple API: PlantUML, Mermaid, GraphViz, BPMN, C4, D2, Excalidraw, Vega charts and more than twenty other formats. Send the diagram source by POST, or encoded in the URL for GET, and get back SVG, PNG or PDF. Handy for documentation, wikis and README files. Free public server; open source, so you can also run it yourself.

API
HTTP-GET
REST

At a glance

API key: Not needed · More APIs with no key
Pricing: Free public server; open source, so you can also run it yourself.
From the browser: Yes (CORS)
Interface: REST, HTTP-GET
Provider: kroki.io
Last checked: Working on November 1st, 2026

More information: https://kroki.io/

Is this your service? Show that it is listed

Put this badge on your website or in your README; it links to this page. About the badge

HTML

<a href="https://free-web-services.com/web-services/media/charts/kroki.html"><img src="https://free-web-services.com/badge.svg" width="208" height="44" alt="Listed on Free Web Services" /></a>

Markdown

[![Listed on Free Web Services](https://free-web-services.com/badge.svg)](https://free-web-services.com/web-services/media/charts/kroki.html)

Example request

curl

curl 'https://kroki.io/graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ'

JavaScript

const response = await fetch("https://kroki.io/graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ");
const text = await response.text();
console.log(text);

Python

import requests

response = requests.get(
    "https://kroki.io/graphviz/svg/eNpLyUwvSizIUHBXqPZIzcnJ17ULzy_KSanlAgB1EAjQ",
    timeout=30,
)
print(response.text)

The JavaScript works in a web page as well as in Node.js 18 or newer.