Node metafetch

Metafetch is a library to fetch and parse metadata from a web page. It can extract standard meta tags, Open Graph data, JSON-LD, favicons, and feeds, and even render client-side JavaScript to get data from Single-Page Applications (SPAs).

Table of Contents

• Key Features
• Installation
• Usage
  • Basic Example
  • Advanced Example (Rendering SPAs & Retries)
• API
  • metafetch.fetch(url, [options])
  • Available Flags
• Instance Management
• Response Data
• License

Key Features

• Comprehensive Metadata: Extracts title, description, URL, site name, images, links, and more.
• Client-Side Rendering: Uses Puppeteer to render JavaScript-heavy sites, ensuring you get the metadata even from SPAs (e.g., React, Vue, Svelte).
• Robust Network Handling: Features built-in request retries with exponential backoff to handle transient network errors gracefully.
• Rich Content Discovery:
  • Finds the best-quality favicon by prioritizing Apple touch icons and largest sizes.
  • Discovers RSS/Atom feeds linked in the page.
  • Parses and flattens structured JSON-LD data.
• Advanced Encoding Detection: Accurately detects character encoding via BOM, HTTP headers, and meta tags to prevent garbled text.
• Highly Configurable: Fine-tune requests with custom headers, user agents, and feature flags to parse only what you need.

Installation

Use NPM to install:

npm install metafetch

Note: puppeteer is a peer dependency and must be installed separately (npm install puppeteer) if you want to use the SPA / client-side rendering feature.

Usage

Basic Example

Here's a simple example using async/await.

import metafetch from 'metafetch';

async function getMeta(url) {
  try {
    const meta = await metafetch.fetch(url);
    console.log(meta);
  } catch (err) {
    console.error(err);
  }
}

getMeta('https://example.com');

This will output a representative object like this:

{
  title: 'Awesome Web Page',
  description: 'A compelling description of the page content, often used by search engines.',
  type: 'article',
  url: 'https://example.com/article-path',
  originalURL: 'https://example.com',
  ampURL: 'https://example.com/article-path/amp',
  siteName: 'Example News',
  charset: 'utf-8',
  image: 'https://example.com/images/featured-image.png',
  favicon: 'https://example.com/favicons/apple-touch-icon.png',
  feeds: [ 'https://example.com/rss.xml' ],
  meta: {
     'og:title': 'Awesome Web Page',
     'og:description': 'A compelling description...',
     'ld:headline': 'Awesome Web Page',
     /* ... other meta and JSON-LD tags ... */
  },
  images: [ 'https://example.com/images/featured-image.png', /* ... */ ],
  links: [ 'https://example.com/another-page', /* ... */ ],
  headers: { 'content-type': 'text/html; charset=utf-8', /* ... */ },
  language: 'en'
}

Advanced Example (Rendering SPAs & Retries)

To get metadata from a client-rendered page or to make your request more robust, use the advanced options.

import metafetch from 'metafetch';

async function getSpaMeta(url) {
  try {
    const meta = await metafetch.fetch(url, {
      // Use puppeteer to render the page
      render: true,

      // Retry up to 2 times on failure
      retries: 2,
      retryDelay: 1000, // 1 second base delay

      // Disable parsing of things you don't need
      flags: {
        images: false,
        links: false
      },
      
      // Pass custom options to the underlying fetch call
      fetch: {
        headers: {
          'Accept-Language': 'en-US,en;q=0.9'
        }
      }
    });

    console.log('Title:', meta.title);
    console.log('Description:', meta.description);

  } catch (err) {
    console.error(err);
  }
}

getSpaMeta('https://my-single-page-app.com');

API

metafetch.fetch(url, [options])

Fetches and parses metadata from the given url.

Options (FetchOptions)

Option	Type	Default	Description
render	boolean	false	If true, uses Puppeteer to render the page's JavaScript before parsing.
retries	number	0	Number of times to retry the request on failure.
retryDelay	number	1000	Base delay in milliseconds for retries (uses exponential backoff).
userAgent	string	Firefox	The User-Agent string to use for the request.
flags	object	{...}	An object to enable/disable parsing specific fields. All flags are true by default. See the list below for all available flags.
fetch	object	{}	RequestInit options passed directly to the fetch call (e.g., { headers: {...} }).

Available Flags

You can pass any of these boolean flags in the flags object to optimize parsing. For example, flags: { links: false, images: false } will skip extracting links and images.

• title
• description
• type
• url
• siteName
• charset
• image
• meta (includes all meta tags and flattened JSON-LD)
• images
• links
• headers
• language
• favicon
• feeds

Instance Management

You can create multiple instances of Metafetch, each with its own default User-Agent.

import { Metafetch } from 'metafetch';

// Create an instance with a custom default User-Agent
const myBot = new Metafetch("MyPersonalBot/1.0");
await myBot.fetch('https://example.com');

// You can also change it later
myBot.setUserAgent("MyPersonalBot/2.0");
console.log(myBot.userAgent); // "MyPersonalBot/2.0"

Response Data

Field	Type	Description
title	string	The page's <title> tag.
description	string	The og:description or description meta tag.
type	string	The og:type meta tag (e.g., "website", "article").
url	string	The final URL after redirects. Prioritizes canonical or og:url.
originalURL	string	The URL that was originally passed to the fetch method.
ampURL	string	The URL from a <link rel="amphtml"> tag, if present.
siteName	string	The og:site_name meta tag.
charset	string	The detected character encoding of the page.
image	string	The og:image or twitter:image meta tag.
favicon	string	The best-quality favicon URL found on the page.
feeds	string[]	An array of RSS/Atom feed URLs discovered on the page.
meta	object	A key-value object of all meta tags and flattened JSON-LD data.
images	string[]	An array of all absolute image URLs on the page.
links	string[]	An array of all absolute hyperlink (<a>) URLs on the page.
headers	object	An object containing the final response's HTTP headers.
language	string	The content language (ISO 639-1) from the <html> tag or headers.

License

(The MIT License)

Copyright (c) 2025 Brahma Dev;

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.