How to use the Web scraper Chrome extension to extract Web data: Part 1
Web scraping is becoming a vital ingredient in business and marketing planning regardless of the industry. There are several ways to scrape the web for useful data depending on your requirements and budget. Did you know that your favourite web browser could also act as a great web scraping tool? You can install the Web Scraper extension from the chrome web store to make it an easy to use data scraping tool. The best part is, you can stay in the comfort zone of your browser while the scraping happens. This doesn’t demand much technical skills which makes it a good option when you need to do some quick data scraping. Let’s get started with the tutorial.
About the Web scraper extension
What you need:
- Google Chrome browser
- A working internet connection
Installation and setup
- Go to https://chrome.google.com/webstore/detail/web-scraper/jnhgnonknehpejjnehehllkliplmbmhn?hl=en
- Add the web scraper extension to chrome.
Once this is done, you are ready to start scraping any website using your chrome browser. You just need to learn how to perform the scraping which we are about to explain.
After installation, open the Google chrome developer tools by pressing F12. (You can alternatively right click on the screen and select inspect element). In the developer tools, you will find a new tab named ‘Web scraper’ as shown in the screenshot below.
Now let’s see how to use this on a live web page. We will use a site called www.awesomegifs.com for this tutorial. This site contains gif images and we will scrape these image URLs using our web scraper.
Step 1: Creating a sitemap
- Go to http://www.awesomegifs.com/
- Open developer tools by right clicking anywhere on the screen and then selecting inspect
- Click on the web scraper tab in developer tools
- Click on ‘create new sitemap’ and then select ‘create sitemap’
- Give the sitemap a name and enter the URL of the site in the start URL field.
- Click on ‘Create Sitemap’
To scrape multiple pages from a website, we need to understand the pagination structure of that site. You can easily do that by clicking the ‘Next’ button a few times from the homepage. Doing this on Awesomegifs.com revealed that the pages are structured as http://awesomegifs.com/page/1/ , http://awesomegifs.com/page/2/ and so on. To switch to a different page, you only have to change the number at the end of this URL. Now, we need the scraper to do this automatically.
To do this, create a new sitemap with the start URL as http://awesomegifs.com/page/[001-125]. The scraper will now open the URL repeatedly while incrementing the final value each time. This means the scraper will open pages starting from 1 to 125 and scrape the elements that we require from each page.
Step 2: Scraping elements
Every time the scraper opens a page from the site, we need to extract some element. In this case, it’s the gif image URLs. First, you have to find the CSS selector matching the images. You can find the CSS selector by looking at the source file of the web page (CTRL+U). An easier way is to use the selector tool to click and select any element on the screen. Click on the Sitemap that you just created, click on ‘Add new selector’. In the selector id field, give the selector a name. In the type field, you can select the type of data that you want to be extracted. Click on the select button and select any element on the web page that you want to be extracted. When you are done selecting, click on ‘Done selecting’. It’s easy as clicking on an icon with the mouse. You can check the ‘multiple’ checkbox to indicate that the element you want can be present multiple times on the page and that you want each instance of it to be scraped.
Now you can save the selector if everything looks good. To start the scraping process, just click on the sitemap tab and select ‘Scrape’. A new window will pop up which will visit each page in the loop and scrape the required data. If you want to stop the scraping process in between, just close this window and you will have the data that was extracted till then.
Once you stop scraping, go to the sitemap tab to browse the extracted data or export it to a CSV file. The only downside is that you have to manually perform the scraping every time since it doesn’t have many automation features built in. If you want to scrape data on a large scale, it is better to go with a data scraping service instead of tools like these. With the next part of this series, we will show you how to make a MySQL database using the extracted data. Stay tuned for that!