Flawless Web Scraping: What Are HTTP Headers and Why It’s Important to Optimize Them?

Most internet users, both commercial and residential, are aware of HTTP headers, but they don’t know anything about them. They can’t tell what they do or the role they play on the internet. Well, HTTP headers are the very fabric of the internet.

They are the foundation around which the web was built. They play a crucial role on the web and are part of every server-to-server and client-to-server communication. Let’s define what an HTTP header is, list different types of it, and explain why it matters for your web scraping operations.

Defining HTTP headers

HTTP is short for Hypertext Transfer Protocol. This internet protocol makes the web functional. Every word you’re reading on the internet right now has been delivered to you via HTTP. Whenever you make a request to view a website or open a web page, your browser sends HTTP requests to the internet and comes back with matching HTTP responses.

There is no HTTP-based communication without HTTP headers. They contain information about the browser you’re using, the website you’re trying to access, and the server that delivers the requested information back to you.

HTTP requests and responses allow internet users to access any online content, including CSS, images, videos, text, JavaScript files, and more. Put simply, the main purpose of HTTP headers is to identify user requests, route them to the appropriate server, and send the results directly to the user.

List of HTTP headers

There are four main types of HTTP headers:

  • Client request headers or HTTP request headers – most relevant for web scraping, this type of HTTP headers only applies to request messages. The information they contain can include details about the client, their location, browser version, and IP.
  • Server response headers or HTTP response headers – define response messages and are sent by a server as a response to a matching HTTP transaction. They contain information about the original request, the connection type, encoding, and more.
  • Entity headers – contain information about the body of the resource identified by the request and present that information in pars such as Content-Language, Content-Length, etc.
  • General HTTP headers – read by both clients and servers, general HTTP headers don’t alter or affect the requested content in any way. They contain information about the date of HTTP transactions, cache-control, connection, etc.

Since the client request HTTP header is the best option for web scraping, let’s quickly review the five main types:

  • User-agent – contains information about the requested HTML layout (tablet, mobile, or PC) and allows for communication between the user’s operating system/browser and the web server.
  • Accept-language – makes sure the user gets the requested content in their preferred language.
  • Accept-Encoding –informs the web server whether there’s a need to use a compression algorithm to handle a user request or not.
  • Accept – determines the type of data the web server should send to the user.
  • HTTP Header Referer – fetches the information about the last web page the user has visited before sending an HTTP request.

HTTP headers can help your web scraping operations, so let’s see the main reasons to optimize them for web scraping.

Different reasons for optimizing HTTP headers

HTTP headers can help improve your web scraping efforts, but they need to be optimized to give the expected results. While proxies can also help improve web scraping by avoiding IP blocks and accessing geo-restricted content, you can do the same by optimizing HTTP headers.

If optimized, each type of HTTP request header can speed up your scraping sessions and bypass security mechanisms. A fully optimized User-Agent can ensure successful web scraping operation by keeping the scraping bots hidden and using different User-Agent messages to appear like genuine internet users.

You can also optimize User-Language HTTP headers to match the IP location and appear more organic to web servers. That’s how HTTP headers help bypass geo-restrictions. The Accept-Encoding header optimization is also an excellent way to expedite your scraping activities by reducing the traffic load due to data compression.

Why this is important for web scraping

Optimizing HTTP headers is the most effective way to streamline communication between the server and the client and allow your web scraping bots to operate securely, quickly, and seamlessly. It will also make sure your bots don’t get detected or blocked and that the data you extract is relevant and accurate.

You can also combine HTTP headers with SOCKS5 and HTTP proxies to increase the anonymity, speed, and security of your web scraping operations. Finally, HTTP headers can also improve the quality of data extracted.

Proxies and HTTP headers

When it comes to proxies and HTTP headers, you have two options – HTTP proxies and SOCKS proxies. Let’s do a quick SOCKS vs HTTP proxy comparison. HTTP proxies are best for scraping HTTP websites without being blocked. SOCKS5 proxies are the best solution for ensuring undetected and secure data transfers between clients and servers.

HTTP proxies are limited by only having access to the HTTP proxy protocol, but they can benefit web scraping by acting as a filter for the scraped online content. SOCKS proxies, on the other hand, are more flexible and can handle a wide range of different protocols, access backend services, bypass firewalls, etc. Check here to better understand how HTTP  proxies are different from SOCKS proxies.


Fully optimized HTTP headers can make sure your scraping bots target multiple websites, scrape the content undetected, and extract the most relevant and accurate data. You can then use that data to your advantage to gain leverage over your competitors.

More importantly, they also allow you to choose the type of content you want to extract. Since they can define what data is available for extraction, HTTP headers are the key element of every web scraping operation.


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