7 Web Scraping Best Practices You Must Be Aware of ['25]

Many websites actively try to prevent or limit web scraping to protect their data. When planning a web scraping project, it’s important to balance legal, technical, and financial factors.

See the top web scraping best practices for an ethical and successful web scraping:

1. Continously parse and verify scraped data

Parsed data needs to be continuously verified to ensure that crawling is working correctly. Data parsing can be left to the end of the crawl process but then users may fail to identify issues early on. We recommend automatically and at regular intervals manually verifying parsed data to ensure that the crawler and parser are working correctly.

It would be disastrous to identify that you have scraped thousands of pages but the data is garbage. These problems take place when the source websites identify scraping bot traffic as unwanted traffic and serve misleading data to the bot.

2. Use proxies and rotate IP addresses

For a reliable and cost-effective web data collection, you can use proxy services.

• The decision between residential and datacenter proxies is based on a number of variables that your tech staff is comfortable with, such as crawl time and proxy settings. You can use any proxy provider depending on their pricing if you are targeting easily crawled websites and don’t care about performance or scalability. See AIMultiple’s proxy pricing benchmark for additional information.
• Mobile proxies to get mobile responses.
• Web unblockers for hard-to-scrape pages that were not successfully retrieved by residential proxies.

Websites use different anti-scraping techniques to manage web crawler traffic to their websites and protect themselves from malicious bot activity. Based on visitor activities and behaviors such as the number of pageviews, session duration, web servers can easily distinguish bot traffic from human activities. For example, many websites implement rate limiting, if you make too many requests frequently, you’ll receive HTTP 429 “Too Many Requests”.

See the market leading proxy companies:

3. Automate your web scraping project

You can build your own web scraper or use a web scraping API to extract data from web sources:

Building your scraper

Python has a large number of web scraping libraries, for example, requests (for HTTP requests) and BeautifulSoup (for HTML parsing) is a common starting point. For larger or more complex projects, you can leverage Scrapy that handles everything from requesting pages (sending multiple requests to one domain), following links, and parsing data. For smaller data extraction uses, BeautifulSoup is the go-to Python framework.

Using a pre-built scraper

There are numerous open-source and low/no-code web scrapers available. You can extract data from multiple websites without writing a single line of code. These web scrapers can be integrated as browser extensions to make web scraping tasks easier. If you have limited coding skills, low/no-code web scrapers could be extremely useful for your tasks.

If you aim to scrape thousands or millions of pages from a well-protected website, you can leverage web scraping APIs that have built-in support for proxies and unblockers. Large websites have complex pagination system and employ anti-bot system. While deciding the right web scraping tool for your specific use case, you can follow these steps:

1. Identify the target website. Although you intend to collect data from a single website, the target website can have different types of pages. For example, product detail pages can be different from a search results pages.
2. Evaluate scraping API providers based on these capabilities. Check if the provider has prebuilt scrapers or actors for your specific site.
3. Ask for sample output for your specific target page type to understand how the output is structured.

Check out the success rate and response times of the top web scraping API solutions.

4. Check out the website to see if it supports an API

APIs establish a data pipeline between clients and target websites in order to provide access to the content of the target website. You don’t have to worry about being blocked by the website since APIs provide authorized access to data. They are provided by the website you will extract data from. Therefore, you must first check out if an API is provided by the website.

There are free and paid web scraping APIs you can utilize to access and get data from websites. Google Maps API, for example, adjusts pricing based on requester usage and volume of requests. Collecting data from websites via APIs is legal as long as the scraper follows the website’s API guidelines.  ¹

5. Respect the ‘robots.txt’ file 

A robots.txt file is a set of restrictions that websites use to tell web crawlers which content on their site is accessible. Websites use robots.txt files to manage crawler traffic to their websites and keep their web servers from becoming overloaded with connection requests. 

Websites, for example, may add a robots.txt file to their web server to prevent visual content such as videos and images from appearing in Google search results. The source page can still be crawled by the Google bot, but the visual content is removed from search results. By specifying the type of bot as the user agent string, you can provide specific instructions for specific bots. 

To understand a website’s instructions for web crawlers, view the robots.txt file by typing  https://www.example.com/robots.txt (see Figure 1). In the image below, you can see the disallow commands determined by the website. A disallow command instructs a web crawler not to access a specific webpage. This means that your bot is not permitted to crawl the web page(s) specified in the disallow command.wl the web page(s) specified in the disallow command.

Figure 1: The ‘robots.txt’ file for Amazon

6. Simulate Human Interaction with Headless Browsers

A headless browser is a web browser without a user interface. All elements of a website, such as scripts, images, and videos, are rendered by regular web browsers. Headless browsers are not required to disable visual content and render all elements on the webpage.

Assume you want to retrieve data from a media-heavy website. A web browser-based scraper will load all visual content on the webpage. Scraping multiple web pages would be time-consuming with a regular web browser-based scraper.

The visual content in the page source is not displayed by web scrapers using a headless browser. It scrapes the webpage without rendering the entire page. This speeds up the data extraction process and helps the scraper bypass bandwidth throttling. 

7. Utilize antidetect browsers to avoid bot detection

Antidetect browsers allow users to mask their browser’s fingerprint, making it more difficult for websites to detect web scraping bots. However, it’s crucial to be mindful of the implications to perform data collection activities ethically and respectfully. They can automatically rotate user agents to mimic different devices and browsers, enabling bots to evade tracking and detection technologies employed by websites.

For instance, when you make a connection request to the target website, the target server obtains collects information sent by your device such as geolocation and IP address.

If you are in restricted location, the server may block your IP address. Antidetect browsers help users change their digital fingerprint parameters, including IP address, operating system, and browser details. This makes it harder for websites to identify and track their activities.

8. Make your browser fingerprint less unique

When you browse the internet, websites track your activities and collect information about you using different browser fingerprinting techniques to provide more personalized content for your future visits.

When you request to view the content of a website, for example, your web browser forwards your request to the target website. The target web server has access to your digital fingerprint details, such as:

• IP address
• Browser type
• Operating system type
• Time cone
• Browser extensions
• User agent and screen dimensions.

If your target web server finds your behavior suspicious based on your fingerprints, it will block your IP address to prevent scraping activities. To avoid browser fingerprinting, use a proxy server or VPN. When you make a connection request to the target website, a VPN and proxy services will mask your real IP addresses to prevent your machine from being revealed.

External Links

• 1. Platform Pricing & API Costs - Google Maps Platform.