Web Crawler & Spider Development
What is Web Scraping?
Web scraping, also called web crawling or web spidering is using a computer to go out and collect information from a website. This helps you collect a large amount of data in a smaller amount of time, as compared to doing the work by hand. There are a number of different types of web scraping tools and techniques. In general though, the web scraping tool will download webpages, extract information, and save it for later.
How Can I Use Web Scraping?
You can use web scraping in a large number of ways. The most common ways businesses use web scraping (in our experience) is to collect data about other companies. Some common tasks include:
- monitoring your competitors’ product prices
- tracking their published employee information on sites like Glassdoor
- see when other companies are hiring new people
- track when companies are expanding into new markets
- create lists of companies to market to
- analyze companies automatically to find the ones best suited to your B2B marketing campaign, and
- optimizing your own business processes.
How Does Web Scraping Work?
In general, web scraping follows a 3-step pattern: download, parse, and store. First, the web scraper needs to download a webpage (or other data) from a website server. This can be done using a number of tools, but the cURL library is quite popular. Second, the web scraper needs to extract the desired information from the page it downloaded. In some cases, this isn’t necessary (for some image crawlers, for example), but for the most part, your crawler will need to extract what you want from the data you’ve downloaded. Third, your web crawler needs to store the data you’ve collected and extracted. There are a range of storage options, from databases to files to spreadsheets.
How are Web Crawlers Developed?
At Potent Pages, we develop web crawlers in the following pattern:
- identify the project requirements and data needed,
- examine the target site to identify the location of the desired data,
- write a program to download the desired webpage(s) or data,
- write a program to extract the desired information from the downloaded pages,
- store the desired data,
- and provide the resulting data in the desired format.
The requirements of the project and the types of data being collected will determine what sort of tools and techniques need to be used. In many cases, a general purpose crawler (e.g. a web spider or a tool that just downloads an entire website) with a custom extraction system will provide the most robust solution. In others, a custom downloading tool is required. The best downloading system just depends on the site and what sort of data is needed.
Similarly, the best processing for a web scraper will depend on the structure of the data collected and what needs to be done with the data. In simpler cases, a simple Python or PHP script will be able to extract and process all of the data required. In more complex situations, a more complex program with custom coding is required.
Storing and providing the data will depend on you and how you will need the data. For some applications, a spreadsheet will do well. In others, a database is required. Along the same lines, if you have a small amount of data, you can receive your results in an email. However, if you have a larger quantity of data, you will most likely need to have the data stored on a server for direct download.
How Much Does Web Scraping Cost?
The cost of web scraping can vary depending upon the difficulty of your project. A simple crawler can range anywhere from $100-$400, and more complex crawlers can cost $800 to $1500 or more. There are also tools that will help you do the work yourself for free. The cost just depends on your needs.
Do I Need a Web Scraper?
Whether you need a web scraper or not will largely depend on the type and quantity of data you’re looking to acquire. If you need a large quantity of structured data collected from a website (like numbers, titles, or tables), or even data that’s partially structured (like HTML webpages), web scrapers may be able to help you. However, if you’re dealing with a small amount of data, it’s often easier to just have someone do the work for you. Similarly, for completely unstructured data, like books or the text within webpages, understanding the meaning of the content can often require a person, at least as of 2018. However, technology is continuously advancing, so if you need some help figuring out what to use and how, please contact us using the form below.
I’m a Collector. Can You Monitor Prices For Me? Can You Find the Best Deals?
If you’re a collector and would rather spend your time collecting and less time looking through websites for good deals, we may be able to develop a web crawler to help you with that! We can track auction and e-commerce sites for items that you’re looking for, extract the information, save it to a database, and examine the prices and other attributes to find deals for you. In some cases, we can even build a crawler to go out and automatically buy good deals that pop up.
Is Web Scraping Legal?
The legality of web scraping can vary depending on your location, how you download content from a website, and what you do with the data. While you will need to consult with an attorney regarding your specific needs, in general, you will need to make sure that your spider doesn’t cause any harm to the website’s server, that you follow the website’s robots.txt file, and that you aren’t violating the website owner’s copyright by using their data.
How do I Download a Website?
Once you’ve decided that you want to download a website using a website using a web crawler, there are a number of methods. These range from web spidering on the general end to targeted crawling for focused work. You’ll want more general web spiders if you’re looking to use the entire content of a webpage (such as tracking page titles, links, etc.). If you’re looking to get specific information from a site (such as product information or data), it can be better in some circumstances to build a crawler to target those needs.
What is a Web Spider?
A web spider is a tool that follows links from page to page, downloading and parsing each page along the way. In this way the web “spider” is crawling the internet “web” made up of links, hence the name. This is how search engine spiders, such as Google’s GoogleBot or Bing’s BingBot work. There are a number of tools that will allow you to download entire sites too, with varying degrees of complexity and efficiency. However, the more efficient spiders require more complex coding techniques.
Can A Scraper Send Notifications or Emails to Me?
Absolutely! A well built web scraper, spider, or other crawler can notify you in a number of different ways.
- If you need to know when there was a successful run or if there was an error, a crawler can be built to send out a text message or email.
- If you need the crawler to send you a summary of the results of the data, you a web scraper can send you an email with an attachment, or with the data in the body of the email itself.
- If you need a large amount of data exported, your web crawler can save your data to a file and upload it to a web server. The crawler can then email you a link to the file so you can download it, without clogging up your inbox
The best web scraper for your needs will be able to send you the data in the best format that works for you.
How Can a Web Scraper Send Data To Me?
A well built web scraper can send you your data however works best for you and your situation. Whether you need a spreadsheet (CSV document, XSLX, or something else), a database (MySQL, for example), or in files (compressed or uncompressed), a well built scraper can provide you the data you need in whatever format you’re looking for.
Who Should I Hire to Build a Web Scraper?
Who you should hire to build you a web scraper will depend on the goals of your scraping project. If you need a large amount of data, or need it in any way customized, a custom web crawler programming firm may be best for you. At Potent Pages, this is what we do.
On the other hand, if you need something simpler, like a few dozen webpages downloaded and some content extracted, you could use one of the many automatic tools available, like 80 Legs or Import.io. If you need help figuring out the best solution to what you need, please contact us using the form below and we would be happy to explain the best crawling options available to you.
Our Web Crawling and Web Scraping Services
Obtaining Data Quickly and Easily, Starting at $200
Our crawlers will get you the data you need, in the format you want.
Do you need to get a lot of data for your business? Are you looking to get a list of potential clients and customers?
Finding, extracting, and processing data by hand can take a really long time and cost a small fortune. We’ve been there too. Even hiring at low wages adds up quickly.
The Data You Need, The Way You Need It
To solve this problem for us and our clients, we develop automated programs to get the data from websites. These “crawlers” do the work that your data entry personel do. They go to the webpage, find the content that you need, and add it to a database.
When we have the data, these crawlers can give you the data in the format that you need it in, whether that is a CSV file, a MySQL database, or a custom format.
Structured & Usable Data for Less
We use state-of-the-art development programs to build custom structured-data crawlers for you. This allows us to offer lower prices for custom programming and development.
Web Scraping Pricing
Our structured data crawlers start at $200 for custom development.
If we already have the data you are looking for, or already have a crawler for your desired site, we can offer you what you need for even less!
If you need custom algorithms or processing, our analytical and programming services begin at $100/hour.
Website Crawler Development Projects
Our previous website crawler development includes building crawlers for information on:
- Yellow Pages
- Theme Forest
- Mojo Themes
- WordPress GPL Themes List
- Drupal GPL Themes list
- Michigan companies filings
- Texas companies filings
- Michigan professional licenses
- Craigslist posts
- NOAA weather (multiple)
- Easy Outsource
- California Bar Association
- Georgia Bar Association
- and many more.
WHAT OUR CLIENT SAYS
at An Investment Firm
Contact us using the form below, and we will build you a crawler to fit your needs.
Let’s Get Started!
Looking for our assistance solving a problem? Have an idea that you want help bringing to life? Interested in learning more? Please send us a message and we will get back to you as soon as possible!
Answers to Some Other Questions
I Want to Build a Web Crawler. Where Do I Start?
After you’ve decided to build a web crawler, and know what website you want to crawl for what data, the next step is to start designing and programming your crawler. The difficulty and efficiency of the crawler you use will depend largely on the language you want to use and the complexity of your project. If you’re getting started on your own, we have a list of web crawler tutorials available here. If you need help at any stage of the process, and are looking for professional assistance, please contact us using the form above.
I see “Spider” and “Scraper” Used Interchangeably. What’s the Difference Between Them?
Web spiders and web scrapers are often used interchangeably in the web crawling and programming industries. However, there are a few differences that center around how the data is collected.
A web spider is a program that specifically follows links, traversing from page to page. This is similar to how a spider will traverse it’s web, hence the name. This sort of tool is generally used for downloading entire sites, or subsections of sites based on a URL pattern.
A web crawler is just a program that goes out and downloads webpages. A web spider is an example of a web crawler, going out and downloading pages based on links, but you can also follow any other pattern. This includes looping through search results, looping through individual URL patterns, downloading all of the URLs listed in a database, etc.
How Fast is My Web Scraper? What Defines the Speed of a Web Scraper?
The speed of a web scraper is generally defined by the number of pages downloaded per time, for example 10000 pages per hour. In general a web scraper’s speed is determined by the delay that the scraper has to wait before it receives a response from the web server. So, for example, if you have an average of a 2s delay between requests, and only parse one page at a time, you’ll end up with a throughput of 1,800 pages per hour. If you can download 100 pages at a time though, you would be able to get that up to 180,000 pages per hour.