fetch set request header: custom header configuration

I. Why toss the request header?

Played the old iron of web crawling know, some sites are like security inspectors, specialized in checking your "luggage". The "baggage" we are talking about here areRequest header (Header), such as User-Agent, Referer, these parameters. It's like when you go to the supermarket and the cashier wants to see your membership code - don't have it? Sorry, I won't let you check out.

Take a real case: last year there was a team doing price comparison software, using the default Header to access the e-commerce site, the result wasTriggers 20 CAPTCHAs per minute. Then they bought residential proxies at ipipgo with a custom Header and the success rate pulled right up to 92%.

// Examples of basic operations
fetch('https://目标网站.com', {
  headers: {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) Your customized message',
    'X-Requested-With': 'XMLHttpRequest'
  }
})

Second, the Header configuration of the three pits

The easiest place for a novice to fall:

Proxy IP + customized Header double insurance

Changing Header alone is like changing your clothes without changing your face - the surveillance camera will still recognize you. This is where ipipgo'sHigh Stash Proxy IPto play the match:

// Full live example
fetch('https://目标网站.com', {
  headers: {
    'User-Agent': 'Mozilla/5.0 (iPhone; CPU iPhone OS 15_4 like Mac OS X) Apple Core',
    
    'Custom-Header': 'ipipgo_proxy_user' // custom logo
  },
  proxy: {
    protocol: 'https', 'host: 'gateway.
    host: 'gateway.ipipgo.net', // proxy server address
    port: 8888, // proxy server address
    auth: {
      username: 'Your account', // password: 'Dynamic key', // password: 'Your account', // password: 'Dynamic key'.
      password: 'Dynamic key'
    }
  }
})

Look at line 7 of theCustom-Header, which is a tawdry operation that many tutorials won't talk about. Putting a special flag on the request, along with ipipgo's traffic statistics feature, allows you to monitor in real time which Header configurations are the most popular.

IV. Guide to avoiding mines in actual combat

A couple of bloody experiences to mention:

1. Don't use your browser's default User-Agent, splice in a real-looking one yourself!
2. Content-Type must match the transmission data, json, do not use the form format
3. For high-frequency visits, use ipipgo'sRotation IP PoolThe header is different for each IP address.

V. Frequently Asked Questions QA

Q：Why doesn't the Header work after I set it?
A: First check if the site is filtered, use ipipgo's debugging proxy to view the original request

Q: How can I prevent being recognized as machine traffic?
A: It is recommended to purchase ipipgo's static residential IP with randomly generated Header parameter

Q: What if I need to deal with cookies?
A: Add the Authorization field to the Header and enable session hold for ipipgo.

VI. Recommendations for tools

Finally, a self-testing tool: the official ipipgo website'sHeader Inspection ToolIt can simulate different device environments to generate standard Header templates, which is 10 times more reliable than those online generators.

Remember, playing Header is like playing drag - clothes should always be changed and identities should be real. Paired with ipipgo's quality proxy IPs, you are guaranteed a smooth flow of requests. When in doubt, go directly to their tech support for a faster response than a delivery boy.