A QuickChart alternative for simple charts — plain params, no JSON-in-a-URL
First, credit where due: QuickChart is a genuinely excellent service. It renders full Chart.js configurations to images, it's open source (AGPL, typpo/quickchart on GitHub), watermark-free, and it can draw practically anything Chart.js can — radar, scatter, bubble, mixed types, annotations, custom fonts. If you need that power, use it. This page is for the other 80% of chart URLs in the wild: a handful of numbers that need to become a line, bar, pie or sparkline in a README, a chat message, or a dashboard <img> tag.
Prefer clicking to reading? Build your chart URL in the live playground → (instant preview, copyable URL).
For that job, two things about QuickChart bite:
- The config is Chart.js JSON, hand-written into a URL. Braces, quotes, brackets — all of it URL-encoded. This is the canonical QuickChart bar chart (verified working today):
That'shttps://quickchart.io/chart?c=%7Btype%3A'bar'%2Cdata%3A%7Blabels%3A%5B'q1'%2C'q2'%2C'q3'%2C'q4'%5D%2Cdatasets%3A%5B%7Bdata%3A%5B12%2C19%2C7%2C24%5D%7D%5D%7D%7D{type:'bar',data:{labels:['q1','q2','q3','q4'],datasets:[{data:[12,19,7,24]}]}}percent-encoded. Fine when a library builds it; miserable to write, template, or code-review by hand. - The free hosted tier is capped at 1,000 charts per month with a 60 charts/min rate limit (per QuickChart's own FAQ, checked September 2026). A README badge on a repo with modest traffic can burn 1,000 image loads in days.
The same chart, as query params
https://mockbird.mockbird.workers.dev/m/demo/chart?data=12,19,7,24&type=bar&labels=q1,q2,q3,q4&title=SignupsThat URL is served live by our shared demo project — no key, no signup, CORS on, and the response is deterministic: the same URL returns byte-identical output forever, with Cache-Control: public, so browsers, proxies and GitHub's image cache do the volume work for you. Each project (the anonymous kind you create in one curl included) gets 10,000 requests/day — vs 1,000/month on QuickChart's free hosted tier.
QuickChart → Mockbird translation
| QuickChart | Mockbird |
|---|---|
?c={type:'line',data:{datasets:[{data:[3,7,4]}]}} | /chart?data=3,7,4 |
?c={type:'bar',…labels:['a','b']…} | /chart?data=…&type=bar&labels=a,b |
multiple datasets:[…],[…] | pipe-separated: ?data=3,7,4|1,5,8&legend=alpha,beta |
stacked bars (options.scales…stacked) | &type=bar&stack=1 |
| pie / doughnut type | ?data=42,31,17,10&type=donut&labels=api,web,cli,other — legend with computed % included; ?hole= sets the ring |
sparkline (/chart?c={type:'sparkline'…}) | /chart/300x80?data=…&type=spark |
&width=600&height=300 | path size: /chart/600x300?… |
&backgroundColor=… | &bg=161b22 (or transparent); &theme=dark for the whole palette |
| dataset colors in JSON | &color=34d399 / &colors=hex,hex,… |
&format=svg | .svg suffix or ?format=svg — same param name |
/qr?text=hello | /qr?data=hello — plus built-in Wi-Fi (?ssid=) and vCard (?name=) payload modes |
| radar / scatter / bubble / sankey / wordcloud | ✘ — keep using QuickChart for these |
Every chart type, live from the demo (these are real <img> tags, view-source them):
Create your own chart URL (10 seconds, no signup)
The demo project above is shared. Your own project takes one curl and gives you a private base URL that also serves a full mock REST API, QR codes, OG images, avatars and placeholder images:
curl -s -X POST https://mockbird.mockbird.workers.dev/api/projects -H 'content-type: application/json' -d '{"name":"charts"}'
# → {"id":"a1b2c3d4e5", "adminKey":"…", …}
# your chart endpoint, immediately:
https://mockbird.mockbird.workers.dev/m/a1b2c3d4e5/chart?data=3,7,4,9,6Or skip the terminal: this link creates a project in the dashboard — no signup. Full parameter reference in the docs and the chart image API guide.
Honest comparison — including where QuickChart wins
| QuickChart (hosted) | QuickChart (self-hosted) | Mockbird /chart | |
|---|---|---|---|
| Chart types | everything Chart.js draws + QR, wordcloud, graphviz, tables | same | line, area, bar (grouped + stacked), pie, donut, spark — that's it |
| URL format | Chart.js JSON, URL-encoded | same | plain query params |
| Free volume | 1,000 charts/month, 60/min (their FAQ, Sep 2026) | unlimited — but you run a server | 10,000 req/day per project |
| Typography | real fonts (Chart.js canvas) | same | PNG uses a blocky pixel font; SVG twin uses system fonts |
| Deterministic bytes | ✘ (re-rendered) | ✘ | ✔ — same URL, same bytes, forever |
| SVG output | ✔ &format=svg | ✔ | ✔ — .svg twin of every chart |
| Watermark | none | none | none |
| Signup / key | none for free tier | — | none |
| Open source / self-host | ✔ AGPL | ✔ | ✘ — hosted only |
| Comes with a mock REST API, QR, OG, avatars | QR yes; rest no | QR yes | ✔ — one base URL for all of it |
Written by the Mockbird maker — bias disclosed. Pick QuickChart when you need Chart.js-grade output: radar/scatter/bubble/sankey, mixed axes, annotations, real typography, or when a library is generating the config anyway — and if volume is the only problem, self-hosting their AGPL server is a legitimate free fix (it just stops being zero-ops). Their hosted paid tiers are also reasonable if you'd rather pay than host. Pick Mockbird when the chart is simple, the config is hand-written, and you want it cached, deterministic, uncapped-for-practical-purposes, and living at the same base URL as your mock API. Facts above verified against QuickChart's official FAQ and live endpoints in September 2026 — check their pages for current terms.
Full API reference in the docs. More guides: free chart image API · free QR code API · OG image API · testing loading & error states. Create your API →