For web scraping enthusiasts, no feeling beats a smooth, fast and accurate data extraction process. Sadly, there are a lot of anti-scrapers out there, like rate limiters and CAPTCHAs, that will make your life harder.
Let's dive right in and discuss each of these crawling tips in detail!
7 Best Web Scraping Tips
Here are the web scraping tips that we used and found to be effective in scraping data without alerting antibots, bot detectors, or slowing down the target site.
1. Use Proxies
One of the challenges to large-scale web scraping is that websites often use various anti-scraping techniques to secure their data. For example, a target site's server registers your IP as soon as a request is made and bans the IP whenever your request rate exceeds a threshold.
The best way to avoid getting your IP banned while scraping is by using a proxy to hide and protect your IP address, making it possible to access and crawl data without getting blocked. You can also frequently change IP addresses and route requests via a proxy network to get around the rate limit.
- Residential proxies: these are servers with IP addresses connected to real residential addresses, making them hard to block. Residential proxies enable you to choose a region and browse the internet covertly as a local user in order to avoid ISP tracking (although this can be expensive).
- Data center proxies: these types of proxies are not affiliated with ISPs. Datacenter proxies are artificially produced using cloud services or data centers, giving you a completely private and anonymous IP address. They're cheap and can handle high workloads with speed and stability.
- Sticky proxies: offer one IP address and help mask a connection, making it hard to detect. To ensure the efficiency of sticky proxies, you need to develop proxy rotators and VPNs. Check out our article on how to rotate proxies in Python to learn more.
- Rotating proxies: they offer a large selection of IP addresses and don't require a proxy rotator. With every single request or browsing session, they create a brand-new and distinct IP address.
An easy way to tackle this dense topic is using ZenRows, which does all the heavy lifting of proxy management for you with its smart proxy feature.
2. Use a Web Scraping API
The main downside of manual web scraping is that when you perform countless unplanned data searches, you appear to spam the websites, and this can get you blocked. A web scraping tip to get around this is to make use of a web scraping API to crawl the data for you.
3. Deal with Crawlers Smartly
Web scraping bots are often seen as malicious bots and might be blocked from the website once detected. Therefore, you should tweak your scrapers to appear as human as possible.
The nature of web consumption for human users and bots is different. For example, bots are fast with requests, and human users are slow.
4. Use Headless Browsers
5. Use CAPTCHA-solving Techniques
CAPTCHAs are one of the most used antibots and are capable of detecting and blocking web scrapers. They're often puzzles and riddles that allow the site to distinguish humans from robots and ensure that a user is legitimate. While the challenges are a breeze to solve for humans, computers struggle for real to solve them, so we need to cover web scraping tips for this topic.
- Use CAPTCHA proxies.
- Don't send unlimited requests from a single IP. Change the pattern and timings of requests to make sure timeouts look organic.
- Improve the image of your web scraper. Try to obtain a database of legitimate user agents, delete cookies when not necessary, align with TLS settings and HTTP headers, etc.
6. Be Cautious of Honeypot Traps
One of the popular anti-scraping techniques to protect websites is honeypot traps, which mimic a service or network in order to lure in the scrapers. Therefore, if someone accesses a honeypot URL, the server can determine if the user is real or not, and you know the rest.
- Avoid public networks.
- Skip hidden links.
- Be a responsible scraper.
- Use a web scraping API.
7. Tips to Use HTTP Headers and agents
One of the reasons why bot detectors can detect and throttle web scrapers is due to incorrectly constructed request headers.
Every HTTP request must include headers because they contain crucial metadata data about incoming requests and primary client data like the user-agent string, unique security tokens, and client rendering features.
You have to give the server some context of your request to get a customized answer from the server. That is where requesting a header comes into play.
- HTTP header
Accept-Languageto define the language understood by the user.
- Enable servers to use HTTP headers
Acceptto define the kind of data format while responding.
- HTTP header
User Agentto determine the user agent being used.
- HTTP header
Accept-Encodingto define the compression algorithm to be used.
In addition to this, you can also rotate the common user agent strings for easy web scraping.
User-agent (UA) is a string that is sent by the user's web browser to a web server to identify the type of browser being used, its version, and the operating system. By default, a web scraper sends queries without user agents, and this is basically snitching on yourself.
We discussed how to use user agents for web scraping in a previous article, as well as some of the best ones. Go to it to learn more.
8. Extra Tip: Scrape Data at Quiet Hours
The server load of your target site is usually at its maximum during peak periods, and scraping during these hours can affect the performance of the website. This can be one of the most useful web scraping tips since scraping data during off-peak times keeps users on track.
9. Extra Tip: Dealing with Robots.txt
Another important consideration is robots.txt. Websites use this file to instruct search bots like Google on how to crawl and index their pages. Many pages are forbidden. Therefore, you should follow this file's instructions to prevent legal repercussions while extracting data from the web and avoid being blocked.
We've covered some of the best web scraping tips to smoothly get data from any website by getting around protections. And meanwhile, some of them are easy to implement, but the antibot game can get really hard in practice. Therefore, many developers opt for using a web scraping API like ZenRows, which bypasses all challenges for you.