What are the best methods to scrape data from AJAX websites?

1 Why scrape AJAX websites?

AJAX websites are becoming increasingly popular due to their improved user experience and faster performance, however, they also present some difficulties for web scraping. Data may be hidden in the browser's developer tools or HTML source code, loaded by JavaScript code, fetched from various sources or endpoints, or encrypted, obfuscated, or protected by anti-scraping mechanisms. To successfully scrape data from AJAX websites, you must use methods that can address these challenges and imitate the browser's behavior.

2 Use a headless browser

A headless browser is one of the best methods to scrape data from AJAX websites. This type of browser runs without a graphical user interface and can be controlled by code, allowing it to render JavaScript, execute AJAX requests, and interact with web page elements like a regular browser. Selenium, Puppeteer, and Playwright are popular headless browsers that enable you to write scripts that automate web scraping tasks such as navigating to URLs, waiting for pages to load or specific elements to appear, filling out forms or clicking buttons, and extracting data from the page or network requests. However, using a headless browser can be slower and more resource-intensive than other methods, can be detected and blocked by some websites with anti-scraping techniques, and can be more complex and error-prone when writing and maintaining the scripts.

3 Use a web scraping framework

A web scraping framework is a tool that provides a high-level abstraction for web scraping, taking care of low-level details such as sending HTTP requests, parsing HTML, managing concurrency, handling errors and retries, and storing and processing data. Popular web scraping frameworks include Scrapy, BeautifulSoup, and Requests. These tools allow you to write code that defines the logic and rules for web scraping, like specifying start URLs or defining selectors or XPath expressions to extract data. You can also define callbacks or functions to process the data and pipelines or components to store or manipulate it. Although using a web scraping framework can make your code more concise and scalable, it may not be able to render JavaScript or execute AJAX requests by itself, and may need additional libraries or tools such as Splash or Pyppeteer to integrate with a headless browser, as well as proxies or headers to bypass anti-scraping measures.

4 Use a web scraping API

A third method to scrape data from AJAX websites is to use a web scraping API. This service offers an easy way to access web data without needing to write any code or install any software. It can handle the complexities of web scraping, such as rendering JavaScript and executing AJAX requests, bypassing anti-scraping mechanisms and captchas, scaling and distributing the web scraping tasks, and providing reliable and consistent data quality. Apify, Scrapinghub, and ParseHub are some of the most popular web scraping APIs. These services allow you to specify parameters and options for web scraping, like the URL or list of URLs to scrape, the data fields or JSON schema to extract, the frequency or schedule to scrape, and the output format or destination to save the data. Using a web scraping API can save time and effort but it also has some drawbacks like being expensive or limited depending on the plan or quota, being less flexible or customizable than other methods, and being dependent on the availability and reliability of the service.