2 Best Anti-Scraping Techniques

There is an effective way to obtain data from the internet, especially at this age of big, big data. The answer is using web crawlers to get data and use it for your analysis.Anti scraping web techniques

In fact, you can create your crawlers using a list of methods: python coding, extensions in browsers, or Scrappy and you can use data extraction tools like Zenscrape.

Although you might have been using the methods easily, there are usually certain points when you will encounter obstacles, a coding war between anti-bots and spiders. This is the work of web developers of creating techniques against scraping. They have set the process down to prevent you from scraping their websites. Here, we will look at two of the techniques and you can go around them.

Table of Contents

1. IP Address

The simplest method for web developers or the website to know about activities relating to web crawling is to track the IP. The website will know the difference if the behavior of the IP is that of a robot or not. A website that receives a great number of requests in a given time and had received those requests from a single IP address simultaneously or it could be over a given period of time, usually a short one. This will make the website cautious and block such IP because it thinks it is a bot.

For this example, the requirement for building an anti-scraping crawler is the frequency and number of visits every unit of time. Here are specific scenarios that you may experience

Example 1: when you make a number of visits in just one second, this is a sign that the process is not conducted by a real human. Humans are slower. Therefore, the website will block the IP for being a robot and sending too many requests too frequently.

What Can You Do?

Reduce the rate at which you are scraping. Use delay time setting such as “sleep” function before carrying out or making the waiting time higher between the 2 steps will simplify things.

Example 2:

When you are visiting a website at an exact interval or pace, it leads to blocking. Humans will not repeat such an accurate pattern in behavior many times. The websites can observe the number of frequency and when it finds out the request is being sent at certain periods with an accurate pattern, such as one in a second, the anti-scraping techniques will be applied.

What Can You Do?

When setting your delay time, make it random for the steps of the crawler. When the scraping speed looks random, the crawlers would appear like a human.

Example 3:

There are advanced anti-scraping techniques that websites use which will apply a complex algorithm to monitor the requests from varying IPs. The techniques will analyze average requests. When there is a clue that the requests are unusual, maybe they are receiving the same number of requests or noticing the same number of visits at a certain time every day, the crawler will be blocked.

What Can You Do?

You should use different IPs over a certain time. If you are looking for ways to go about it, check cloud servers and proxy service. They offer rotated IPs. Sending requests through these IPs make the crawler act not completely like a bot. This lowers the chance of being block.

You can always use Zenscrape for your web scraping activities for ease and smooth collection of data.

2. Captcha

These are the kinds of images that ask you to perform certain activities. Examples are asking you to click on something specific, asking you to make simple calculations, asking you to click certain pictures.

The name of this type of image is Captcha. It stands for Completely Automated Public Turing test to tell Computers and Humans Apart. This program is automated publicly to know if the user is a robot or a human. The program usually creates challenges that are believed to be possible for humans to solve. These include fill-in-the-blanks, degraded images, or equations.

Over the years, the process has been evolving with many platforms using Captcha as a technique against scraping. Earlier, it used to be hard to pass the Captcha test directly. Later, there are new open-source tools that allow you to pass the Captcha challenges although the tools demand very high skills in programming.

In fact, some individuals develop feature libraries of their own and make image-recognition techniques using deep learning or machine learning skills to solve Captchas.

What Can You Do?

With people who do not have advanced skills which can rival professionals those at Zenscrape, it is advisable you shouldn’t trigger the Captcha at all. Randomize or slow down the scraping process.

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