HTTP Headers: What You Should Know When Scraping

The world of web scraping is continually growing and expanding, which leads to a lot of repetitive and common questions asked by internet users interested in all the benefits that web crawling and scraping has to offer. Individual and business users are all interested in one thing — to find out how to avoid getting blocked by target websites and servers.

The next thing they’re most interested in is the way to increase the quality of extracted data. Well, the answer is quite simple — an HTTP header Referer. HTTP headers excel at avoiding getting your web scraper blocked.

While proxies and rotating IP addresses can pretty much help you achieve the same goal, these alternatives aren’t nearly as effective as HTTP headers in preventing your web crawlers and scrapers from getting detected and blocked.

We’re going to tell you what an HTTP header Referer is, how it is used, and how it can help you improve your web scraping efforts.

What Are HTTP Headers?

The main purpose of HTTP headers is to enable both the server and the internet user to transfer further data within the response or request header. Each HTTP transaction has optional parameters or HTTP headers. Both HTTP responses and requests can have different HTTP headers.

Web scraping is incredibly popular these days as it’s one of the best ways to extract huge amounts of accurate data and publicly available intelligence using the power of automation. While setting up a web scraper is a complex task, some of the proven techniques, such as the use of proxies, are an easy way to get into web scraping and avoid getting blocked by target websites.

At the same time, optimizing and using HTTP headers for the same purpose is also an effective way to collect data. In fact, this technique is one of the most effective ways to avoid being blocked by various data sources. They also ensure that the extracted data is of excellent quality.

How Are They Specified?

There are five most essential HTTP headers that you can optimize for web scraping.

This HTTP header passes data regarding identifying the application, version, software, operating system, and type, allowing for the information target to determine what kind of HTML layout to use to respond.

Web servers commonly practice authenticating the User-Agent request header to perform checks that allow data sources to detect and remove any suspicious requests. The more you alter the data each HTTP header carries, the more you reduce the chance of getting blocked when scraping target websites.

2. Accept-Language

This HTTP header further removes any chance of getting your scraping bots detected and banned. It sets languages based on the client’s IP location and target domain, thus eliminating any suspicion of bot-like behavior and the risk of target sites blocking the web scraping process.

3. Accept-Encoding

Optimizing this particular HTTP header allows you to save traffic volume, which is very important for business operations that require heavy traffic load. The user still gets the required data while the web server saves its resources by transferring a huge amount of traffic.

4. Accept

Many users overlook configuring the request header according to the target web server’s accepted format. Fortunately, the Accept HTTP header makes it easier to configure the request header and establish a more organic communication with the server while also reducing the chance of getting blocked along the way.

5. HTTP Header Referer

HTTP header Referer makes your web scraping traffic more organic, but to do that, you need to specify the target website before you start your web scraping operation. That way, you can slip past any anti-scraping measures and extract data without any risk of being blocked.

If you’re interested, you can find more information on Oxylabs’ HTTP header referer article about all of the necessary HTTP headers for web scraping.

Where Are They Used?

Using and optimizing HTTP headers allows you to reduce the chance of getting your web scraper detected or blocked by the target website. They are quite beneficial to businesses as they greatly improve the quality of extracted and retrieved data from the target server.

Aside from defining the quality of data extracted, the primary purpose of HTTP headers is to determine the type of data that will be extracted from web servers. They carry additional information to web servers. The more you optimize the content of this additional data, the more you appear to be an organic user, thus reducing the chance of being banned or blocked.

How They Help Improve Web Scraping

HTTP headers allow you to scrape the websites that utilize measures against scraping. In other words, HTTP headers will enable you to scrape target sites that don’t want to be scraped.

They make your script unidentifiable, and the more you randomize your HTTP headers (user agents), the more you can scrape without any interference. However, it’s even more important to mention that HTTP headers allow you to appear as a real user, which is crucial to avoiding getting your IPs banned.


The more you learn and know about web scraping and its technicalities, the more you can scrape the web with success. If you depend on accurate data to go about your daily business, using HTTP headers is an advanced web scraping method that provides innovative ways to scrape multiple target web servers without getting blocked or flagged.

They improve your web scraping efforts by allowing you to not only appear as a real user and bypass all security measures but also by allowing you to choose the type of data you want to extract. While using HTTP headers might sound complex, it all comes down to how eager you are to get ahead of the competition.

Networking specialist with a passion of sharing my knowledge and learning new thing in the process.