Font Detection API Identify Fonts on Any Website
Detect every font used on any webpage programmatically. The Nodium font detection API loads the page in a real browser, analyzes computed styles, and returns a structured list of font families, weights, and sources. No browser extension needed.
Free plan includes 100 API calls/month. No credit card required.
How Font Detection Works
Accurate font identification using a real browser rendering engine.
We load the page
Nodium loads the target URL in a headless Chromium browser. All JavaScript executes, web fonts download, and CSS styles are fully applied, just like a real user visiting the site.
Analyze computed styles
We traverse the DOM and inspect computed font styles on every text element. This captures the actual rendered fonts, not just what the CSS declares. Fallback fonts and system fonts are detected accurately.
Return structured data
You receive a JSON response with every font family found on the page, including font weights, styles, and the source (Google Fonts, Adobe Fonts, self-hosted, or system). Clean, structured data ready for your application.
What the Font Detection API Returns
Rich, structured font metadata from any webpage.
API Parameters for Font Detection
Enable font extraction with the metadata extraction parameters.
| Parameter | Type | Default | Description |
|---|---|---|---|
extract_metadata | boolean | false | Enable metadata extraction mode. Returns a JSON response with page metadata instead of a screenshot image. |
metadata_fonts | boolean | false | Include font information in the metadata response. Lists all font families, weights, styles, and sources found on the page. |
Detect Fonts in One API Call
Pass extract_metadata=true and metadata_fonts=true to get font data.
curl "https://api.nodium.io/api/v1/screenshot?\
url=https://example.com&\
extract_metadata=true&\
metadata_fonts=true" \
-H "X-API-Key: ndm_your_api_key"{
"url": "https://example.com",
"metadata": {
"fonts": [
{
"family": "Inter",
"weights": [400, 500, 600, 700],
"styles": ["normal"],
"source": "google_fonts",
"url": "https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700"
},
{
"family": "JetBrains Mono",
"weights": [400],
"styles": ["normal"],
"source": "google_fonts",
"url": "https://fonts.googleapis.com/css2?family=JetBrains+Mono"
},
{
"family": "Georgia",
"weights": [400, 700],
"styles": ["normal", "italic"],
"source": "system",
"url": null
}
]
}
}const response = await fetch(
"https://api.nodium.io/api/v1/screenshot?" +
new URLSearchParams({
url: "https://example.com",
extract_metadata: "true",
metadata_fonts: "true",
}),
{
headers: { "X-API-Key": "ndm_your_api_key" },
}
);
const data = await response.json();
// List all Google Fonts used on the page
const googleFonts = data.metadata.fonts
.filter((f) => f.source === "google_fonts")
.map((f) => f.family);
console.log("Google Fonts:", googleFonts);
// => ["Inter", "JetBrains Mono"]Use Cases for Font Detection
Design research and inspiration
Discover what fonts successful websites use. Build a database of font pairings from real-world examples. Analyze typography trends across industries and competitors without manually inspecting each page.
Brand consistency auditing
Verify that all your web properties use the correct brand fonts. Detect unauthorized font usage or inconsistencies across multiple domains, subdomains, and microsites in your organization.
Competitive analysis
Analyze competitor websites to understand their design choices. Track font changes over time to spot rebranding efforts, design system updates, or A/B testing of typography.
Accessibility audits
Identify problematic font choices that affect readability. Detect overly thin font weights, decorative fonts used for body text, or missing fallback fonts that could cause layout shifts for users without the specified fonts installed.
Why Use an API Instead of Browser Extensions
Font detection via API offers advantages that manual inspection and browser extensions cannot match.
Automated and scalable
Analyze fonts on hundreds or thousands of URLs programmatically. No manual clicking through pages or installing browser extensions on every machine.
Accurate rendering
Nodium uses headless Chromium which renders fonts exactly like a real browser. Computed styles are inspected after full page rendering, catching fonts loaded via JavaScript and CSS @import.
Structured output
Get clean JSON data with font families, weights, styles, and sources. No parsing HTML or scraping extension UIs. The response is ready for your database, spreadsheet, or application.
Combine with screenshots
Request both a screenshot and font metadata in a single API call. Get a visual reference alongside the structured font data for comprehensive design documentation.
Frequently Asked Questions
What is a font detection API?
How accurate is the font detection?
Can the API detect fonts loaded via JavaScript?
Does font detection work alongside screenshots?
What font sources can the API identify?
Start detecting fonts today
Identify every font on any website with a single API call. 100 free requests per month, no credit card required.