meta-og: Server-Side Metadata Extraction Library

meta-og is a lightweight library for extracting metadata, including the title and meta tags, from web pages. Designed for server-side environments, it utilizes a two-step process for efficiency. It first attempts to fetch metadata using a lightweight approach and falls back to Puppeteer for more complex pages.

Features

• Title and Meta Tag Extraction: Extract title, description, and og:/twitter: meta tags.
• Optimized Performance: Minimizes resource usage by blocking unnecessary assets like images and fonts when using Puppeteer.
• Fallback Mechanism: Uses Puppeteer if lightweight fetching fails.
• Compatible with Serverless Environments: Utilizes @sparticuz/chromium for compatibility with serverless platforms like AWS Lambda.

Installation

npm install meta-og @sparticuz/chromium puppeteer

Usage

Example

import { metaOG } from "meta-og";

(async () => {
  const url = "https://example.com";
  try {
    const metadata = await metaOG(url);
    console.log("Metadata:", metadata);
  } catch (error) {
    console.error("Error fetching metadata:", error);
  }
})();

Output

{
  "title": "Example Domain",
  "description": "This domain is for use in illustrative examples in documents.",
  "og:title": "Example Domain",
  "og:description": "Illustrative examples in documents."
}

API Reference

metaOG(url: string): Promise<MetaResult>

Fetches metadata from the given URL.

Parameters

• url (string): The URL of the web page to fetch metadata from.

Returns

• MetaResult: An object containing the title, description, and other meta tags.

Example

const metadata = await metaOG("https://example.com");
console.log(metadata.title); // Outputs: Example Domain

MetaResult Interface

Defines the structure of the returned metadata object.

| Key | Type | Description | |---------------|--------|------------------------------------------------------| | title | string | The title of the web page. | | description | string | The description meta tag of the web page. | | [key: string] | string | Additional meta tags (e.g., og:title, og:image). |

Internals

Lightweight Fetch Method

The library first attempts to fetch metadata using fetch for improved performance.

Puppeteer Fallback

If the lightweight method fails, Puppeteer launches a headless browser to fetch metadata from JavaScript-rendered pages.

Advanced Configuration

Puppeteer Options

The Puppeteer instance is configured to run in headless mode with options to minimize resource usage:

• Blocks images, fonts, and stylesheets.
• Uses @sparticuz/chromium for compatibility with serverless environments.

Custom Extraction Logic

The extractMetaTags function uses regular expressions to parse metadata directly from HTML. You can modify this logic for specific requirements.

Error Handling

If an error occurs during the metadata fetching process, it is logged, and an exception is thrown to notify the caller.

License

This library is open-source and available under the MIT License.

For issues or contributions, feel free to visit the GitHub repository.