9 Web Scraping Challenges You Should Know | Octoparse
Web Scraping Challenges
Bot access
Web page structures
IP blocking
Captcha
Honeypot traps
Slow/unstable load speed
Dynamic content
Login requirement
Real-time data scraping
Web scraping has become a hot topic among people with the rising demand for big data. More and more people hunger for extracting data from multiple websites to help with their business development. However, many challenges, such as blocking mechanisms, will rise when scaling up the web scraping processes, which can hinder people from getting data. Let’s look at the challenges in detail.
Web scraping may not work because:
1. Bot access
The first thing to check is that if your target website allows for scraping before you start it. If you find it disallows for scraping via its, you can ask the web owner for scraping permission, explaining your scraping needs and purposes. If the owner still disagrees, it’s better to find an alternative site that has similar information.
2. Complicated and changeable web page structures
Most web pages are based on HTML (Hypertext Markup Language). Web page designers can have their own standards to design the pages, so web page structures are widely divergent. When you need to scrape multiple websites, you need to build one scraper for each website.
Moreover, websites periodically update their content to improve the user experience or add new features, which often leads to structural changes on the web page. Since web scrapers are set up according to a certain design of the page, they would not work for the updated page. Sometimes even a minor change in the target website requires you to adjust the scraper.
Octoparse uses customized workflow to simulate human behaviors so that to deal with different pages. You can modify the workflow easier to adapt to the new pages.
3. IP blocking
IP blocking is a common method to stop web scrapers from accessing data of a website. It typically happens when a website detects a high number of requests from the same IP address. The website would either totally ban the IP or restrict its access to break down the scraping process.
There are many IP proxy services like Luminati, that can be integrated with automated scrapers, saving people from such blocking.
Octoparse Cloud extraction utilizes multiple IPs to scrape one website at the same time to not only make sure one IP would not request too many times but also keep the high speed.
4. CAPTCHA
CAPTCHA(Completely Automated Public Turing test to tell Computers and Humans Apart) is often used to separate humans from scraping tools by displaying images or logical problems that humans find easy to solve but scrapers don’t.
Many CAPTCHA solvers can be implemented into bots to ensure non-stopping scrapes. Although the technologies to overcome CAPTCHA can help acquire continuous data feeds, they could still slow down the scraping process a bit.
5. Honeypot traps
Honeypot is a trap the website owner puts on the page to catch scrapers. The traps can be links that are invisible to humans but visible to scrapers. Once a scraper falls into the trap, the website can use the information it receives(e. g. its IP address) to block that scraper.
Octoparse uses XPath to precisely locates items to click or to scrape, which largely reduces the chance of falling into the trap.
6. Slow/unstable load speed
Websites may respond slowly or even fail to load when receiving too many access requests. That is not a problem when humans browse the site as they just need to reload the web page and wait for the website to recover. But scraping may be broke up as the scraper does not know how to deal with such an emergency.
Octoparse allows users to set up auto-retry or retry loading when certain conditions are met to solve the issues. It can even execute customized workflow under preset situations.
7. Dynamic content
Many websites apply AJAX to update dynamic web content. Examples are lazy loading images, infinite scrolling and show more info by clicking a button via AJAX calls. It is convenient for users to view more data on such kind of websites but not for scrapers.
Octoparse can easily scrape those websites with different functions like scrolling down the page or AJAX Load.
8. Login requirement
Some protected information may require you to log in first. After you submit your login credentials, your browser automatically appends the cookie value to multiple requests you make the way most sites, so the website knows you’re the same person who just logged in earlier. So when scraping websites requiring a login, be sure that cookies have been sent with the requests.
Octoparse can simply help users to log in to a website and save the cookies just like a browser does.
9. Real-time data scraping
Real-time data scraping is essential when it comes to price comparison, inventory tracking, etc. The data can change at the blink of an eye and may lead to huge capital gains for a business. The scraper needs to monitor the websites all the time and scrape data. Even so, it still has some delay as the requesting and data delivery take time. Furthermore, acquiring a large amount of data in real-time is a big challenge, too.
Octoparse scheduled Cloud extraction can scrape websites at the minimum interval of 5 minutes to achieve nearly real-time scraping.
There will certainly be more challenges in web scraping in the future but the universal principle for scraping is always the same: treat the websites nicely. Do not try to overload it. What’s more, you can always find a web scraping tool or service such as Octoparse to help you handle the scraping job.
Artículo en español: 9 Desafíos de Web Scraping que Debes ConocerTambién puede leer artículos de web scraping en El Website Oficial
Artikel auf Deutsch: 9 Herausforderungen beim Web ScrapingSie können unsere deutsche Website besuchen.
9 Web Scraping Challenges You Should Know | Octoparse
Web Scraping Challenges
Bot access
Web page structures
IP blocking
Captcha
Honeypot traps
Slow/unstable load speed
Dynamic content
Login requirement
Real-time data scraping
Web scraping has become a hot topic among people with the rising demand for big data. More and more people hunger for extracting data from multiple websites to help with their business development. However, many challenges, such as blocking mechanisms, will rise when scaling up the web scraping processes, which can hinder people from getting data. Let’s look at the challenges in detail.
Web scraping may not work because:
1. Bot access
The first thing to check is that if your target website allows for scraping before you start it. If you find it disallows for scraping via its, you can ask the web owner for scraping permission, explaining your scraping needs and purposes. If the owner still disagrees, it’s better to find an alternative site that has similar information.
2. Complicated and changeable web page structures
Most web pages are based on HTML (Hypertext Markup Language). Web page designers can have their own standards to design the pages, so web page structures are widely divergent. When you need to scrape multiple websites, you need to build one scraper for each website.
Moreover, websites periodically update their content to improve the user experience or add new features, which often leads to structural changes on the web page. Since web scrapers are set up according to a certain design of the page, they would not work for the updated page. Sometimes even a minor change in the target website requires you to adjust the scraper.
Octoparse uses customized workflow to simulate human behaviors so that to deal with different pages. You can modify the workflow easier to adapt to the new pages.
3. IP blocking
IP blocking is a common method to stop web scrapers from accessing data of a website. It typically happens when a website detects a high number of requests from the same IP address. The website would either totally ban the IP or restrict its access to break down the scraping process.
There are many IP proxy services like Luminati, that can be integrated with automated scrapers, saving people from such blocking.
Octoparse Cloud extraction utilizes multiple IPs to scrape one website at the same time to not only make sure one IP would not request too many times but also keep the high speed.
4. CAPTCHA
CAPTCHA(Completely Automated Public Turing test to tell Computers and Humans Apart) is often used to separate humans from scraping tools by displaying images or logical problems that humans find easy to solve but scrapers don’t.
Many CAPTCHA solvers can be implemented into bots to ensure non-stopping scrapes. Although the technologies to overcome CAPTCHA can help acquire continuous data feeds, they could still slow down the scraping process a bit.
5. Honeypot traps
Honeypot is a trap the website owner puts on the page to catch scrapers. The traps can be links that are invisible to humans but visible to scrapers. Once a scraper falls into the trap, the website can use the information it receives(e. g. its IP address) to block that scraper.
Octoparse uses XPath to precisely locates items to click or to scrape, which largely reduces the chance of falling into the trap.
6. Slow/unstable load speed
Websites may respond slowly or even fail to load when receiving too many access requests. That is not a problem when humans browse the site as they just need to reload the web page and wait for the website to recover. But scraping may be broke up as the scraper does not know how to deal with such an emergency.
Octoparse allows users to set up auto-retry or retry loading when certain conditions are met to solve the issues. It can even execute customized workflow under preset situations.
7. Dynamic content
Many websites apply AJAX to update dynamic web content. Examples are lazy loading images, infinite scrolling and show more info by clicking a button via AJAX calls. It is convenient for users to view more data on such kind of websites but not for scrapers.
Octoparse can easily scrape those websites with different functions like scrolling down the page or AJAX Load.
8. Login requirement
Some protected information may require you to log in first. After you submit your login credentials, your browser automatically appends the cookie value to multiple requests you make the way most sites, so the website knows you’re the same person who just logged in earlier. So when scraping websites requiring a login, be sure that cookies have been sent with the requests.
Octoparse can simply help users to log in to a website and save the cookies just like a browser does.
9. Real-time data scraping
Real-time data scraping is essential when it comes to price comparison, inventory tracking, etc. The data can change at the blink of an eye and may lead to huge capital gains for a business. The scraper needs to monitor the websites all the time and scrape data. Even so, it still has some delay as the requesting and data delivery take time. Furthermore, acquiring a large amount of data in real-time is a big challenge, too.
Octoparse scheduled Cloud extraction can scrape websites at the minimum interval of 5 minutes to achieve nearly real-time scraping.
There will certainly be more challenges in web scraping in the future but the universal principle for scraping is always the same: treat the websites nicely. Do not try to overload it. What’s more, you can always find a web scraping tool or service such as Octoparse to help you handle the scraping job.
Artículo en español: 9 Desafíos de Web Scraping que Debes ConocerTambién puede leer artículos de web scraping en El Website Oficial
Artikel auf Deutsch: 9 Herausforderungen beim Web ScrapingSie können unsere deutsche Website besuchen.
Data Scraping – Challenges and Best Practices – BinaryFolks
Need to gather data in order to make a decision? Looked around and tried everything? Still didn’t manage to get your hands on the required data? Let me guess. There’s data on a website and there’s no option to download and copy paste failed you!! FOMO? Worry not, we got you covered.
The art of data scraping was omnipresent. The only difference is that, data scraping used to be a manual process earlier. Manual data scraping is definitely obsolete now as its tedious and time consuming and prone to human errors. Also, some websites has thousands of web pages now which makes it impossible to manually scrape by custom web scrapers. Thus automation! But, why is data scraping so essential for a business?
Whether you are in ecommerce, retail, sales, marketing, travel, hospitality, research, education etc, survival of the fittest is the motto everywhere. There exists cut-throat competition and you have to come up with different and innovative ideas everyday, and there is a trap here; Come up with these ideas faster than your competitors.
With the help of data scraping, this somehow seems a little easier as you have access to a lot of information, customer preferences and also competitor strategies, making it easier for executives to take crucial decisions with a glance at the structured data, once it has been analyzed. But, developing a web scraper is not as easy as it is for me to write about it. There are considerable amount of roadblocks in this path and it’s always better to have a clear vision of the challenges before one proceeds with data scraping.
Let us walk through a few things that can seem challenging when it comes to data scraping.
Challenges in data scraping
1. Bots
Websites are free to choose whether they will allow web scrapers bots or not on their websites for data scraping purpose. There are websites that actually do not allow automated web scraping. This is mainly because, at most times these bots scrape data with the intention of gaining competitive advantage and drain the server resources of the website they are scraping from, thus adversely affecting site performance.
2. Captchas
The main purpose of captchas are to separate humans from bots by displaying logical problems that humans find easy to solve but making it difficult on the bots. So, their basic job is to keep spam away. In presence of captcha, basic scraping scripts will tend to fail, but with new advancements, there are generally measures to subsist these captchas, in an ethical manner.
3. Frequent structural changes
In order to keep up with the advancements in UI/UX and to add more features, websites undergo regular structural changes. The web scrapers are specifically written with respect to the code elements of the webpage at the point of setup, so, frequent changes complicates the codes, giving scrapers some sort of a hard time. Though every structural change will not affect the web scraper setup, but as any sort of change may result in data loss, it is recommended to keep a tab on the changes.
4. Getting Banned
If a web scraper bot sends multiple parallel requests per second or unnaturally high no of requests, there’s a good chance that you will cross the thin line of ethical and unethical scrapping and get flagged and ultimately banned. If the web scraper is smart and has sufficient resources, they can carefully handle these kind of counter measures and make sure they stay at the right side of the law and still achieve what they want.
5. Real time data scraping
Real time data scraping can be of paramount importance to businesses as it supports immediate decision making. With the always fluctuating stock prices to the ever changing product prices in eCommerce, this can lead to huge capital gains for a business. But deciding what’s important and what’s not in real time is a challenge. Also, acquiring large data sets in real time is an overhead too. These real time web scrapers use a Rest API to monitor all dynamic data available in the public domain and scrape data in “nearly real time” but attaining the “holy grail” still remains a challenge.
There is a thin line between data collection and causing damage to the web by careless data scraping. As web scraping is a such an insightful tool and with the immense effect it has on businesses, web scraping should be done with responsibility. With a little respect we can keep a good thing going.
Take a look at the best practices list for web scraping that we compiled.
[1] Respect the
A file has all the information stored on the pages that a web scraper can crawl and pages that they cannot. Be sure to check the file before you start with the scraping. If they have blocked bots altogether, its best to leave the site alone as its unethical to scrape the site in that scenario.
[2] Take care of the servers
It is very important to think about the acceptable frequency of requests and number of requests sent to the host server. Web servers are not flawless. They will crash if the load they can take is exceeded. Sending too many requests too soon can results in server failure and that creates a bad user experience for visitors on the website. While data scraping, keep a reasonable amount of gap between requests and try and keep the number of parallel requests in control.
[3] Don’t scrape during peak hours
Take it as a moral responsibility to scrape websites during non-peak periods, so that, visitors’ user experience is hampered in no way. This has a catch for the scraping business too: it will significantly improve the scraping speed.
[4] Use a headless browser
What is it? The Google blog says: “ It’s a way to run the Chrome browser in a headless environment. Essentially, running Chrome without chrome! “. These web browsers don’t have a GUI, but are executed via a command-line interface or using network communication. One definite advantage of using headless browsers is that they are faster than real browsers. Also, while using a headless browser, you don’t need to load a site fully, headless browser can just load the HTML portion and scrape, resulting into amore lightweight, resource saving and time saving scraping.
[5] Beware of Honey Pot Traps
There are pages inside some websites that a human will never click on but a web scraper bot that is clicking on every link might. These are specifically designed for web scrapers and once the honey pot links are clicked, it’s highly likely that you will get banned from that site for ever.
Skip the challenges and get to your data
One of the major reasons for ethical web scraping is that data is not readily available for analysis. Data driven analysis, insights and strategies play a huge part in enterprise building and is paramount to organizational success. Either the website doesn’t have APIs or they have a strict rate limit that will get exceeded quickly.
A custom built web scraping software will automatically extract data from multiple pages of any website according to your specific business requirements. But, due to the ever-evolving nature of the websites and the fact that websites don’t follow typical structures and rules, there is no way a one-size fits all web scraper can carefully handle the challenges to web-scraping a particular site.
Also, when the scraping needs to be done at scale, the difficulty increases by many folds.
Here at BinaryFolks, we cautiously avoid backdated technologies and practices that misses the modern handling of data (Like, Vue js, React js based websites, AJAX, etc.. Instead we use modern and cutting edge techniques (like, headless browser method ( Selenium, Phantomjs etc. ), scrappy etc. making it easy to ethically scrape very sophisticated and modern websites pretty easily. Require help in web scraping? Take a look at our web scraping work here.
Frequently Asked Questions about challenges in web scraping
What are some challenges with web scraping?
Web scraping may not work because:Bot access. The first thing to check is that if your target website allows for scraping before you start it. … Complicated and changeable web page structures. … IP blocking. … CAPTCHA. … Honeypot traps. … Slow/unstable load speed. … Dynamic content. … Login requirement.More items…•Jan 22, 2021
What are the challenges and opportunities that HR professionals encounter in the era of data scraping bots?
Challenges in data scrapingBots. Websites are free to choose whether they will allow web scrapers bots or not on their websites for data scraping purpose. … Captchas. … Frequent structural changes. … Getting Banned. … Real time data scraping.
Why is web scraping not allowed?
Web Scraping is illegal It is because there are people don’t respect the great work on the internet and use it by stealing the content. Web scraping isn’t illegal by itself, yet the problem comes when people use it without the site owner’s permission and disregard of the ToS (Terms of Service).Aug 16, 2021