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Web scraping is a well-known technique for extracting data from various websites. The presumption is that you can scrape any data if it is publicly available. So are there any unscrapable websites?
I have to share the good news with you – technically, all of them are scrapable if you know how to do it. The thing is that some are harder to crack than others. Certain webmasters can be very anxious and overly protective of their content. They try to guard it by using various anti-scraping techniques and tools. It’s understandable but quite tricky.
You see, the internet has its own set of rules, and if you’re able to access data publicly, you can easily collect it too. Of course, you should abide by the laws concerning copyright protection if you publish your findings.
First things first, let’s establish when you should start panicking that something went wrong in your attempt to scrape a particular website:
Now, let’s dive in and dissect some of the most common challenges you can experience when web scraping.
Captchas’ primary purpose is to filter human traffic from various bots, including web scrapers. They present multiple challenges to people who visit certain websites. These challenges are easily solvable for human beings but will complicate the flow for bots.
Captchas can easily be triggered by unusual traffic or many connections from a single IP address. Besides, a suspicious scraper fingerprint can set it off, too.
If you’ve already encountered Captcha, try to rotate your IP address. Of course, this works great if you have a high-quality proxy network. So the best thing is to always prepare for web scraping by getting high-quality, “clean” residential proxy IP addresses. This way, there’s less chance to encounter Captchas.
Otherwise, you can use a Captcha solving service. Certain websites use real people to solve these challenges for you! The price is pocket-friendly too – it costs around 1-3 dollars per 1,000 challenges
You can find more tips & tricks on how to avoid Captchas here.
The popular webmaster’s method detects whether they are getting unwanted visitors, like web scrapers, on their websites. Essentially, it’s bait for web scrapers in the form of links in the HTML that is not visible to regular site visitors.
These traps can redirect your scraper to endless blank pages. Then this anti-scraping tool fingerprints the properties of your requests and blocks you.
First, when you’re developing a scraper, make sure that it will only follow visible links to avoid any honeypot traps. If you think that your scraper has already bitten this bait, look for “display: none” or “visibility: hidden” CSS properties in a link. If you detect one, it’s time to do an about-face in a track.
A quick heads up – webmasters tend to change their honeypots’ URLs and texts as they know that web scrapers learn to avoid them. So keep your web scrapers up to date!
Besides, keep in mind that webmasters may also try to protect their content by continually changing the site’s markup, attributes, structure, CSS, etc. If you haven’t prepared your scraper for these changes, it can abruptly stop when entering this unfamiliar environment.
Since all websites continuously change, you need to test the website you’re planning to scrape and detect all the changes. Then, update your scraper so that it won’t be shocked by the new environment. After all, you have to take into account its feelings too.
So, these are the main challenges that you can come across when you scrape the web. You can see that it is more than possible to overcome all these challenges if you know how to do so.
One last word before you go. Keep in mind that if the website you’re trying to scrape sees that requests are coming from a single IP address, you’ll be quickly blocked. Use good quality proxy servers with a large pool of IP addresses for your web scraping projects. And don’t forget to use automatic IP rotation!
Say hello to Mariam! She is very tech savvy - and wants you to be too. She has a lot of intel on residential proxy providers, and uses this knowledge to help you have a clear view of what is really worth your attention.