What is a chart image API?

A chart image API accepts a chart definition and returns a finished SVG or PNG rendered on the server. The image works in emails, reports, dashboards, bots, and anywhere else an image URL can be used.

Can I validate a chart without rendering it?

Yes. POST /validate is public, free, and read-only. It returns blocking errors, complete diagnostics, and an optional verified replacement config without creating an image, saving data, or consuming a render.

Do I need an account or API key?

No. Keyless GET requests include 100 renders per month per IP. Authenticated POST requests use an API key or dashboard session and count against the account's plan.

Is the Szum Image API free?

Yes. Free includes 500 renders per month. Creator is $9/month for custom themes and 5,000 attribution-free renders. Pro adds production capacity and optional overage billing.

Which image formats does the API return?

The API returns SVG or PNG image bytes. Set format to svg for scalable vector output or png for raster output; no client-side chart runtime is required.

How is Szum different from other chart image APIs?

Szum combines a concise purpose-built chart grammar, chart-aware validation, and curated themes instead of merely rendering a large third-party library configuration. The focus is fewer visual decisions and publication-ready output by default.

Chart images for apps, agents, and automations

The Image API for publication-ready charts.

Send one concise JSON definition. Validate it first, then get a designed SVG or PNG ready for emails, reports, dashboards, and automations.

POST/chart

200 OK

Request

curl https://szum.io/chart \
  -H "Authorization: Bearer sz_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "version": "2026-03-20", "format": "svg",
    "theme": "editorial", "width": 720, "height": 480,
    "title": "Quarterly revenue",
    "marks": [{ "type": "barY", "x": "quarter", "y": "revenue", "label": true }],
    "data": [
      { "quarter": "Q1", "revenue": 42 }, { "quarter": "Q2", "revenue": 58 },
      { "quarter": "Q3", "revenue": 67 }, { "quarter": "Q4", "revenue": 81 }
    ],
    "y": { "display": false }
  }'

Response

image/svg+xml · 720 × 480

Designed before it reaches production.

The API handles the visual decisions and the rendering infrastructure, so your integration only needs to describe the chart.

Publication-ready by default.

Six curated themes coordinate typography, color, spacing, axes, labels, and grid lines without a wall of styling options.

An image, not a runtime.

The API returns finished SVG or PNG bytes. No browser automation, canvas setup, or client-side JavaScript is required.

One definition everywhere.

Reuse the same chart definition through the Image API, MCP server, Figma plugin, web editor, and interactive embeds.

From JSON to image.

A short path from structured data to an artifact that works anywhere an image does.

Define the chart.

Send a flat data array, one or more semantic marks, and a curated theme. The free validation endpoint checks whether the definition can produce a chart.

Call one endpoint.

Use a keyless GET for a simple image URL or an authenticated POST when you need account quota and usage headers.

Use the finished image.

Put the returned SVG or PNG in an email, report, dashboard, bot, social preview, or automated workflow.

Built for production.

The details an integration needs, with the operational depth kept in the API documentation.

SVG and PNG output

Choose scalable vector output or a ready-to-use raster image in the chart definition.

Keyless GET and authenticated POST

Start without an account, then use an API key or dashboard session for authenticated renders. Read the authentication guide.

Global edge caching

GET images are cached close to their viewers. Cache hits are fast, free, and do not consume another render.

Typed SDK or raw HTTP

Use the TypeScript SDK or copy an example for curl, Python, Go, or Ruby.

Chart-aware validation

Check JSON structure, field mappings, values, scales, and mark combinations without rendering or consuming quota. Diagnostics include exact paths and verified replacement configs.

A complete chart grammar

Ten composable marks, six themes, and 1,951 Google Fonts cover the decisions that matter. Browse the marks and themes.

Put charts where JavaScript cannot go.

Static images make designed charts useful beyond the browser tab where they were created.

Emails and reports.

Drop an image URL into transactional emails, newsletters, PDFs, and recurring reports. See the email integration guide.

Bots and automations.

Generate a chart in a scheduled job, CI pipeline, Slack bot, or agent workflow and return a finished artifact.

Products and previews.

Serve edge-cached images in dashboards, public pages, Open Graph previews, Notion, and Confluence.

Start for free. Upgrade when your work gets serious.

Create with six curated themes for free. Creator makes every chart yours; Pro supports production-scale use.

Free

Create with Szum.

MCP, Studio, API, and Figma plugin
Six curated themes
PNG and SVG exports
Interactive embeds

500 renders a month

Creator

$9/ month

Make every chart yours.

Everything in Free
Custom themes and Google Fonts
No Szum branding
Email support

5,000 renders a month

Pro

$29/ month

Run Szum at scale.

Everything in Creator
Optional overage billing
Priority email support

25,000 renders a month

See full pricing details Try without an account: 100 API images a month per IP. Cached views and local interactions are free.

Chart Image API questions.

The short version before you make the first request.

What is a chart image API?: It accepts a chart definition and returns a finished SVG or PNG rendered on the server. The image works in emails, reports, dashboards, bots, and anywhere else an image URL can be used.
Can I validate a chart without rendering it?: Yes. POST /validate is public, free, and read-only. It checks structural and semantic chart validity without creating an image, saving data, or consuming a render. The response includes blocking errors, complete diagnostics, and an optional verified replacement config.
Do I need an account or API key?: No. Keyless GET requests include 100 renders per month per IP with a 10 request-per-second IP ceiling. Authenticated POST requests use an API key or dashboard session; API keys add a 30 request-per-second credential ceiling. See the authentication guide.
Is the Szum Image API free?: Yes. The Free plan includes 500 renders per month and a commercial license. Creator is $9/month for custom themes and 5,000 attribution-free renders. Pro is $29/month for 25,000 included renders, production headroom, and optional overage billing. See pricing and plan details.
Which image formats does the API return?: SVG for scalable vector output and PNG for raster output. Set the format in the chart definition; the response body is the finished image rather than HTML or a client-side chart runtime.
How is Szum different from other chart image APIs?: Szum combines a concise purpose-built chart grammar, chart-aware validation, and curated themes instead of merely rendering a large third-party library configuration. The focus is fewer visual decisions and publication-ready output by default. Compare it with QuickChart or the retired Google Image Charts.

Render your next chart through the API.

Start with a keyless image URL or create a free account for authenticated renders, saved charts, and usage visibility.