Trouble with Puppeteer: querySelector returning null for certain websites

Other Questions Puppeteer
1

I’m having issues with web scraping using Puppeteer. For some websites, the querySelector method is returning null. I’ve looked at other solutions online, but none have worked so far. Here’s a sample of my code that’s not working as expected:

const webScraper = require('puppeteer');

(async () => {
  const webBrowser = await webScraper.launch();
  const webPage = await webBrowser.newPage();

  await webPage.goto('https://example-clothing-store.com/product/12345');

  const priceElement = await webPage.evaluate(() => {
    return document.querySelector('.product-price');
  });

  console.log(priceElement);

  webBrowser.close();
})();

I’m trying to grab the price of a product, but it’s coming back as null. Any ideas on what might be causing this or how to fix it? I’m pretty new to web scraping, so any help would be appreciated!

2

I’ve dealt with this exact issue before. One thing to consider is that some websites implement lazy loading, where content appears as you scroll. In such cases, you might need to simulate scrolling before attempting to grab the price.

Here’s what worked for me:

await page.evaluate(() => {
  window.scrollBy(0, window.innerHeight);
});
await page.waitForTimeout(2000); // Give it time to load

Also, have you checked if the site uses iframes? If so, you’ll need to switch to the correct frame before querying. Lastly, some sites use unconventional methods to display prices (like images or custom attributes) to deter scraping. In those cases, you might need to get creative with your selectors or look for alternative data sources.

3

I’ve encountered similar issues with Puppeteer before. One common reason for querySelector returning null is that the content might be dynamically loaded after the page loads. Try adding a wait before executing your selector. You can use page.waitForSelector() or increase the timeout in page.goto(). Also, make sure the selector ‘.product-price’ is correct for that specific website. Some sites use different class names or IDs for pricing elements. If those don’t work, you might need to check if the site is using any anti-scraping measures. In that case, you may need to look into more advanced techniques like using a headless browser or rotating user agents.

4

hey, have u tried using page.waitForSelector() before running ur querySelector? sometimes websites load content dynamically, so the element might not be there right away. also, double-check if ‘.product-price’ is the right selector. maybe try inspecting the page source to make sure. good luck with ur scraping project!