ChartKitBETA

Charts for newsletters

Newsletter platforms differ - some want Markdown, some rich HTML - but almost all accept remote images. ChartKit gives you one stable URL per issue graphic.

Platform patterns

Ghost and many MD-first tools accept `!alt`. Buttondown/Medium-like editors often need the raw `<img>` from the ChartKit copy field.

Substack’s editor varies - test both Markdown image syntax and the image insert dialog with your URL.

Use cases

  • Creator economy weekly digests with a single “chart of the week”.
  • Company internal Substack-style updates with KPI sparklines rendered as PNG.
  • Paid tiers that get the same chart URL gated by the newsletter platform, not ChartKit.

Examples

PNG suitable for narrow newsletter columns

https://getchartkit.com/api/chart?type=line&labels=Issue+20,Issue+21,Issue+22,Issue+23&s0=4200,4450,4680,4910&s0name=Opens&title=Open+rate+trend&format=png&w=580&h=320&valueFormat=compact

HTML `<img>` (many ESPs)

<img src="https://getchartkit.com/api/chart?type=line&labels=Issue+20,Issue+21,Issue+22,Issue+23&s0=4200,4450,4680,4910&s0name=Opens&title=Open+rate+trend&format=png&w=580&h=320&valueFormat=compact" alt="Monthly revenue" width="600" height="360" />

Markdown (for MD→HTML pipelines)

![Monthly revenue](https://getchartkit.com/api/chart?type=line&labels=Issue+20,Issue+21,Issue+22,Issue+23&s0=4200,4450,4680,4910&s0name=Opens&title=Open+rate+trend&format=png&w=580&h=320&valueFormat=compact)

Donut “share of voice” graphic

https://getchartkit.com/api/chart?type=donut&labels=Essay,Podcast,Video&s0=55,30,15&s0name=Mix&title=Content+mix&format=png&w=480&h=420

Horizontal bar for sponsor rankings

https://getchartkit.com/api/chart?type=horizontal-bar&labels=Sponsor+A,B,C,D&s0=12,9,7,5&s0name=Clicks&format=png&w=560&h=340

Build the chart for this issue

Adjust fields and copy URL, HTML, Markdown, or an AI prompt. See the [URL parameters](/docs/url-parameters) reference if you are editing links by hand.

Preview

Monthly Revenue

Copy

Show snippets
URL
https://getchartkit.com/api/chart?type=bar&labels=Jan,Feb,Mar,Apr,May&s0=12000,18000,15000,22000,27000&s0name=Revenue&title=Monthly%20Revenue&w=580&h=320&valueFormat=compact&format=png
HTML
<img src="https://getchartkit.com/api/chart?type=bar&labels=Jan,Feb,Mar,Apr,May&s0=12000,18000,15000,22000,27000&s0name=Revenue&title=Monthly%20Revenue&w=580&h=320&valueFormat=compact&format=png" alt="Monthly Revenue" width="580" height="320" />
Markdown
![Monthly Revenue](https://getchartkit.com/api/chart?type=bar&labels=Jan,Feb,Mar,Apr,May&s0=12000,18000,15000,22000,27000&s0name=Revenue&title=Monthly%20Revenue&w=580&h=320&valueFormat=compact&format=png)

How it works

  1. Draft issue text, freeze numbers, build the chart, copy Markdown or HTML.
  2. Paste early - some editors strip hotlinked images and require upload; download PNG from the URL if needed.
  3. Archive issues should keep working: avoid expiring intermediaries when possible.

Use with ChatGPT or Claude

LLM-written issues should reference ChartKit URLs explicitly so text and graphics stay in sync.

Compare with charts for email for ESP-specific HTML notes.

FAQ

Markdown or HTML?

Try Markdown in MD-native tools; fall back to `<img>` when previews break.

SVG allowed?

Prefer PNG for widest newsletter compatibility.

Free?

ChartKit public chart URLs are meant for normal trial throughput.

Can I use Google Sheets data?

Google Sheets chart generator.

JavaScript?

Not required for readers.

More ChartKit tools