node-fetch is a lightweight library that provides a fetch()-like API for making HTTP requests in Node.js.
It is a light-weight implementation of the Fetch API, which is mostly compatible with the browser's version.
node-fetch is primarily known as almost identical package fetch() is included in web browsers so it
shares the same use common API. It's great starting point for people coming from front-end environment.
Mechanize is a Ruby library for automating interaction with websites. It automatically
stores and sends cookies, follows redirects, and can submit forms — making it behave
like a web browser without needing an actual browser engine.
Key features include:
- Automatic cookie management
Stores cookies received from servers and sends them back on subsequent requests,
maintaining session state across multiple pages.
- Form handling
Can find, fill in, and submit HTML forms programmatically. Supports text inputs,
selects, checkboxes, radio buttons, and file uploads.
- Link following
Navigate through pages by clicking links using their text content, CSS selectors,
or href patterns.
- History and back/forward
Maintains a browsing history, allowing you to go back and forward through visited pages.
- HTTP authentication
Supports basic and digest HTTP authentication.
- Proxy support
Can route requests through HTTP proxies.
- Redirect handling
Automatically follows HTTP redirects (configurable).
Mechanize is one of the oldest and most established web interaction libraries in Ruby.
It is best suited for scraping traditional server-rendered websites with forms and
multi-page workflows. For JavaScript-heavy sites, a browser automation tool like
Selenium or Playwright is recommended instead.
```javascript
const fetch = require('node-fetch');
// fetch supports both Promises and async/await
fetch('http://httpbin.org/get')
.then(res => res.text())
.then(body => console.log(body))
.catch(err => console.error(err));
const response = await fetch('http://httpbin.org/get');
// for concurrent scraping Promise.all can be used
const results = await Promise.all([
fetch('http://httpbin.org/html'),
fetch('http://httpbin.org/html'),
fetch('http://httpbin.org/html'),
])
// POST requests
await fetch('http://httpbin.org/post', {
method: 'POST',
headers: { 'Content-Type': 'application/json' },
body: JSON.stringify({ name: 'John Doe' }),
})
// Proxy use:
const agent = new https.Agent({
rejectUnauthorized: false,
proxy: {
host: 'proxy.example.com',
port: 8080
}
});
await fetch('https://httpbin.org/ip', { agent })
// setting headers and cookies
const headers = new fetch.Headers();
headers.append('Cookie', 'myCookie=123');
headers.append('X-My-Header', 'myValue');
await fetch('https://httpbin.org/headers', { headers })
```
```ruby
require 'mechanize'
agent = Mechanize.new
# Navigate to a page
page = agent.get('https://example.com')
puts page.title
# Find and click a link
page = page.link_with(text: 'Products').click
# Extract data from the page
page.search('.product').each do |product|
name = product.at('.name').text
price = product.at('.price').text
puts "#{name}: #{price}"
end
# Fill in and submit a login form
login_page = agent.get('https://example.com/login')
form = login_page.form_with(action: '/login')
form['username'] = 'user@example.com'
form['password'] = 'password123'
dashboard = agent.submit(form)
# Cookies are maintained automatically
puts dashboard.title # "Dashboard"
# Download a file
agent.get('https://example.com/report.csv').save('report.csv')
```