Data scraping is quite a normal part of internet life. After all, the search engines we all use every day get their information through the same processes of web crawling that data scrapers use as well.
In fact, the web is full of bots crawling and scraping their way through pages. So do they often get detected?
The short answer is yes. If you want to scrape data from a website, then you should be aware that there’s a good chance that your robot will get detected. And once your bot is detected, it will almost always get blocked from the site as a result.
Why is that? And is there anything you can do to prevent your bot from getting detected?
That’s what we will discuss in this short article below. We’ll answer both those questions, plus a few more. After finishing this quick read, you’ll know a bit more about how to avoid your web scraper getting detected. Ready to do some sneaky scraping?
What is web scraping?
Web scraping is the automated process of a robot (also called crawler or spider) crawling its way through a web page to extract certain parts of information (data) from that page.
Now you might have heard of web crawling before and how that’s basically how search engines gather their data (with Google’s Googlebot as the prime example). Web scraping is slightly different in the sense that it doesn’t just crawl pages to display that information somewhere else, but it actively extracts (or harvests) data from a page.
The extracted data can then be used for all sorts of different purposes, from competitive price monitoring to keyword rank tracking for search engine optimization (SEO) purposes.
Servers vs. spiders
So why do some websites (or, well, their servers) try to block spiders?
Well, for quite a lot of different reasons, in fact.
First and foremost, spiders and web scraping techniques are used by scammers and people with like-minded malicious intent to steal data from a website.
Do you remember the massive Cambridge Analytica scandal? The personal information of millions of Facebook users was scraped from the social media platform and unlawfully (and unethically) used without their consent.
And that’s probably the most common example of why scraping is seen as bad. Because it’s used to gather personal data and contact information without people’s consent, this data is then used to try and scam people, for example, through spam emails.
But spiderbots don’t have to be used for scraping. They can also be used to attack a website, for example, by overloading a website with traffic, so it crashes.
And then there is the bot traffic that doesn’t have malicious intent, but that’s still an annoyance to a website owner/server. After all, if a lot of spiders crawl a website at the same time, it can really slow a website down.
This, in turn, will result in a bad user experience for real customers visiting the site (not to mention that slow speed is considered an important SEO ranking factor!).
So how do websites try and stop bots from crawling their domains?
How websites detect scraping
Robots tend to act, well, robotically. And that’s primarily how websites detect them.
You see, a human user will slowly scroll through a site, maybe have a break mid-page to get a coffee, or click on a random link that might not be the most obvious choice. Robots, on the other hand, tend to crawl a site in a very structured way (and at lightning speed).
So when a user on a website goes through every single page of the site from top to bottom, it’s quite obvious to a server that this is a bot at work.
Another way in which bots give themselves away is by the User-Agent they specify (or, well, forget to specify). You see, when you send a request to a server to view a certain page, the server checks your User-Agent. This specifies that you are using Google Chrome as a browser, for example.
If the User-Agent isn’t specified, the server can’t tell what kind of entity this user is. The logical conclusion is that it’s a robot and not a human, so the server will probably block your bot as a response.
These are just a few examples. Think of unusual session duration times, unusual amounts of traffic from certain geo locations that are not normal for that website, or simply weird interactions with the website.
How to scrape without getting detected
Say you want to gather Google Scholar results. Sadly, there is no official Google Scholar API that you can use to collect your data. So, you have to scrape the data using a bot instead.
But Google doesn’t want you to. So it’ll do its best to put enough roadblocks in your bot’s path to stop it in its tracks. Luckily, you can still manage to avoid all these hurdles and get your hands on the data you want.
Well, you have two main options:
- Build your own scraper
- Use a scraping tool
The first option is free. But you need a lot of technical know-how to ensure that you create a web scraper that’s programmed to not get detected. Let alone the time and effort it takes to build a sophisticated scraper like that.
The second option isn’t always free, but it will save you the time and effort of having to do it yourself. And if you’re planning to gather a sizable amount of data, investing in a proper tool practically always pays itself off: for instance, you can try out SERPMaster’s Google Scholar API solution for it.