# Free Chart APIs

Page: https://free-web-services.com/web-services/media/charts/

Chart APIs turn your numbers into a chart without a charting library in your own code: you send the data in a URL or a request and get back an image you can put in a web page, an e-mail or a report. Some also draw diagrams from text.

## Services

| Service | API key | Formats | Free use |
|---|---|---|---|
| [GXChart WebChart](https://free-web-services.com/web-services/media/charts/gchart-webchart.md) | Not needed | XML | - |
| [Image-Charts](https://free-web-services.com/web-services/media/charts/image-charts.md) | Not needed | - | The free plan is free forever with unlimited charts, but adds a small 'image-charts.com' watermark; paid plans remove it. |
| [Kroki](https://free-web-services.com/web-services/media/charts/kroki.md) | Not needed | - | Free public server; open source, so you can also run it yourself. |
| [mermaid.ink](https://free-web-services.com/web-services/media/charts/mermaid-ink.md) | Not needed | - | Free and open source, no key needed. |
| [QuickChart](https://free-web-services.com/web-services/media/charts/quickchart.md) | Not needed | - | Free plan with a monthly limit; paid plans for more charts. |

## Questions

**Which free chart APIs work without an API key?**  
GXChart WebChart, Image-Charts, Kroki, mermaid.ink and QuickChart work without a key, according to their documentation. Most keyless services ask you to keep the number of requests reasonable, and some ask for a User-Agent that names your app.

**Are these chart APIs really free?**  
The services here can be used without paying, at least on a free plan or free tier, often with limits such as a number of requests per day or non-commercial use only. The table above quotes what each service says about its free use; check the provider's own terms before you rely on it.

**How up to date is this list?**  
The address of every service is checked about once a week, and services that stop working or stop being free are removed. This list last changed on November 8th, 2026.