Choosing HTTP Headers for Web Scraping

Businesses that want to gain a competitive edge over their competitors find web scraping very important. Web scraping is the process of extracting relevant and useful public information from another website. This method can be used to retrieve large amounts of data that can be useful for your business.

On the downside, target websites can block websites undertaking web scraping activities when they become suspicious. Nonetheless, it is possible to reduce blocks during web scraping by using HTTP headers. 

What are HTTP headers?

HTTP headers are parameters that are used to convey additional information between the browser and the server. Basically, HTTP headers facilitate the transfer of information between a server and a client with the response or the request.

These headers are optional and may contain arbitrary data. 

Why are HTTP headers important for web scraping?

HTTP headers are important for web scraping in several ways. They include:

Obtains quality data

If you are planning on doing any web scraping operations, you need to ensure that you get quality data that will give your company a competitive edge. This is where HTTP headers come in. With HTTP headers, you can collect accurate and quality data that will be relevant to your business. 

Prevents blocking

When you are web scraping, your IP address is likely to be blocked if the site notices suspicious activity. However, using HTTP headers can lower the chance of detection when you are web scraping in such sites. 

If your website has a proper user-agent HTTP header string, the network protocol will identify your browser. The header provides details of the browser making the request including its operating system, and version. Consequently, this will prevent block. 

Main HTTP headers used in web scraping

HTTP headers are in two forms: request headers and response headers. Some of the most common HTTP headers that are used to aid in the process of web scraping include:

User-Agent

The User-Agent is a request header that sends an identification string to identify the software sending the request. This header gives the user a unique user agent string that identifies them based on the operating system, application type, software version, or software type. 

This header will tell the server the type of computer you are using; for instance, if you are using Windows 10 or 8 and the type of browser. This way, the server can easily prepare the response based on the type of server. 

Using a User-Agent string prevents the server from noticing ban activities as this could result in a block. The string is easy to manipulate so that the web server believes that you are using a different device. 

Most web servers often authenticate User-Agent request headers to trigger any suspicious activity. For this reason, it is highly advisable to keep manipulating the User-Agent request header information to prevent getting blocked. 

Also, make sure to rotate between the most common User Agents to prevent detection and have a successful web scraping operation. The User-Agent that you use should be valid to lower the chances of getting blocked. You can check this blog post for more information about the most common User-Agents. 

HTTP Accept-Language

This is another request HTTP header that conveys information to the server in the language that the client can understand. In simple terms, this header lets the server know which language is more preferable when sending back the response. This is especially useful if the server is unable to know the language to use through other methods like URL. 

When using this header, it is recommendable to set the preferred language based on your IP location and data-target domain. Otherwise, making requests from multiple languages will announce your presence as a bot.

HTTP Header Accept

This is a request header that is used for content negotiation. The client/browser uses this header to inform the server of the preferred format to use when sending back the response. It is used to inform the server of the media types to use such as audio and text. 

It is important to manipulate this header appropriately based on the accepted format of the web server. This will enhance communication between the client and the server and reduces the chance of blocks.

HTTP Accept-Encoding

When doing web scraping, you can use this request header to inform the web server of the preferred compression algorithm. This means that the response will come in a compressed format. This can prevent a huge load of traffic and save on storage space, which is beneficial to both the client and the server. 

HTTP Header Referer

The HTTP Header Referer works by providing the page address of the previous website before sending the request to the server. It can portray that you are from an authentic website and make the traffic for your website appear more organic. Consequently, this will reduce your chances of being blocked. 

Conclusion

Web scraping can help you acquire important information that will help grow your business. However, to ensure effective web scraping operations and prevent chances of being blocked, you need to use HTTP headers. Overall, the most common user agents can make the scraping tasks easy and successful.