Finding a good web scraper for your data collection tasks can be daunting, especially given the sheer number of service providers. Fortunately, you can narrow down the list by looking for several features. This article highlights the top 7 features to consider when choosing a web scraper. But first, let’s understand what web scraping is.
What is Web Scraping?
Web scraping, also known as web data extraction or web harvesting, refers to retrieving publicly available data from a website. There are two forms of web scraping, namely:
- Manual web scraping: this form of data extraction relies on manual methods such as copying text from a website and pasting it into a new tab or document. This approach is slow, as you have to visit one page at a time. Additionally, it is sometimes fraught with inaccuracies that arise from human errors.
- Automated web scraping: this approach involves using software, known as web scrapers, that can extract specific data from a webpage. Automated web scraping is faster and more accurate compared to manual web scraping.
What is a Web Scraper?
A web scraper is a software or a script designed to execute commands that enable it to extract specific data from websites. You can obtain a web scraper from technology companies. Specifically, those that specialize in creating scraping tools in exchange for a set fee. Alternatively, you can create one from scratch using languages such as Python, Ruby, and more.
Web scrapers are designed to automatically send HTTP and HTTPS requests to target websites. They then receive responses from the servers. What follows is a process known as parsing. This process decodes the data sent as part of the responses. You see, web servers send HTML files that contain unstructured data written in HTML. Parsing entails extracting the relevant data from these files and arranging it in a structured format. The scraper then stores the structured data in a CSV or JSON file for download.
Uses of Web Scrapers
Web scrapers collect data that can be applied in myriad situations. Generally, the use cases of web scrapers include:
- Market research, including price, product, and competitor monitoring
- Reputation and review monitoring
- Travel fare monitoring
- Ad verification (fraud monitoring)
- Academic research
- Monitoring news sites
- Lead generation
Features to Look in a Web Scraper
There are numerous off-the-shelf web scrapers available on the market. Therefore, it is easy to get confused. So, what should you look for when choosing a good scraper? Below are the features you should consider:
- Proxy servers and proxy rotator
- Web crawlers
- Built-in CAPTCHA-solving tool
- JavaScript rendering
- Auto-retry system
- Bulk scraping capabilities
- Automation capabilities
Proxy servers and proxy rotators
A proxy server is an intermediary that routes internet traffic through itself, assigning them a new IP address. This creates a setup where web requests appear to originate from the proxy rather than the computer sending the requests. In the context of web scraping, a proxy server bypasses geo-restrictions and prevents IP bans. A proxy rotator, on the other hand, changes the assigned IP addresses periodically.
Web Crawlers
A crawler is a bot that scours the internet to discover and index web pages. A good web scraper should have an integrated crawler that explores new pages on a website as well as webpages on other websites (by following internal and external links). In doing so, the crawler discovers relevant data that the scraper extracts.
Built-in CAPTCHA-Solving Tool
As web scraping becomes more ubiquitous, web developers are deploying anti-scraping techniques to protect their web servers against processing requests from bots. One of the techniques used is CAPTCHA and reCAPTCHA puzzles. These puzzles intend to distinguish between humans and bots. If they are not solved, the web page will not be accessible. A good web scraper features a CAPTCHA-solving tool that bypasses this problem.
JavaScript Rendering
Most dynamic websites are JavaScript-heavy. As such, a typical web scraper can primarily read HTML and XML files. Therefore, when such tools may not be able to extract data from JavaScript-heavy sites. A good web scraper should have JavaScript rendering capabilities that enable it to harvest data from as many websites as possible.
Auto-Retry System
A good web scraper should be capable of automatically sending requests if the initial requests fail.
Bulk Scraping Capabilities
An excellent web scraper will enable you to extract data from hundreds of web pages simultaneously. This property promotes speed and efficient data collection.
Automation
A web scraper will have scheduling capabilities that enable it to conduct recurring data collection jobs automatically. This characteristic promotes convenience.
Conclusion
A good scraper will have several key features. These include proxies and proxy rotators, JavaScript rendering, and bulk scraping capabilities. It also includes automation, an auto-retry system, built-in crawlers, and CAPTCHA-solving abilities.
