Websocket vs. HTTP: The Fundamentals You Need To Know
As you get into the finer details of web scraping, you’ll find that specific tweaks and configurations not only allow you to become more effective at acquiring the info you want but also maintain better efficiency. Most of these calibrations have to do with specifying settings and which to ones use. For example, there’s specifying the user agent, setting a delay, and managing cookies. Many of these settings are applicable in certain conditions and may either bolster or hinder your web scraping activities.
One such consideration is understanding the differences between protocols, such as WebSocket and HTTP.
The HTTP protocol is sort of a forerunner of the WebSocket protocol. As both operate over a Transmission Control Protocol (TCP) connection, they offer different functionalities and are applicable in different use cases. Your job is to understand which is better and when.
This article explores the fundamentals you need to know to better work with both HTTP and WebSockets in your web scraping.
What Are HTTP and WebSocket?
It’s best to start with a working understanding of the technologies themselves. Once you’re better acquainted, you can more cohesively grasp subsequent points, such as their use cases, particularly in web scraping. This should help you avoid making erroneous or nonsensical high-level comparisons, such as “WebSocket vs. TCP.”
Actually, let’s start with that, because HTTP is built on top of TCP, and WebSockets is essentially an “upgraded” — but still distinct — version of HTTP.
TCP is the primary transport layer protocol of the Internet. It’s responsible for ensuring that data is transferred reliably from one computer to another. TCP uses a connection-oriented approach, meaning that a connection must be established between two computers before any data can be transferred. This process involves exchanging — or “handshaking” — packets of information between the two computers. Once a connection has been established, TCP guarantees that all data will be delivered in order and without errors. TCP comes earlier on in the process of two machines communicating with each other, and both HTTP and WebSocket occur later.
Now, on to HTTP and WebSocket.
HyperText Transfer Protocol (HTTP) is a protocol that’s used to request and transfer data on the internet, and it’s practically the foundation of the world wide web. It is built on top of the TCP protocol and provides a way for computers to request information from servers and receive responses. HTTP is used by web browsers to retrieve web pages and by applications to communicate with Application Programming Interfaces (APIs).
So, when you enter a URL into your web browser, your computer/browser sends an HTTP request to the appropriate website’s server. That server then responds with an HTTP response, which contains the requested data. Opening Chrome and typing in Google.com, for example, makes your browser send an HTTP request to Alphabet’s server, which then sends your the appropriate response: the Google homepage.
In web scraping, software can send HTTP requests to websites and parse the responses in order to extract data such as text, images, or even entire pages of HTML code.
WebSocket, standardized in 2011, is a computer communications protocol that provides full-duplex communication channels over a single TCP connection. It enables persistent connection between a web browser and a server. So once the connection is established, it stays open until the client or server decides to close it. This allows for low-latency (minimal delay) communication between the two endpoints. WebSockets are used in applications where real-time data needs to be exchanged between the client and server.
WebSockets are a better choice to use over HTTP when real-time communication is required. For example, if you were building a chat application, you would want to use WebSockets so that messages can be sent and received as soon as they are typed. With HTTP, there would be a delay in sending and receiving messages since the connection would have to be re-established with each new message.
WebSockets are used in web scraping to provide a persistent connection between the client and server, meaning the scraping client can send requests and receive responses without having to re-establish a connection each time. This is particularly useful for scraping if you want to reduce the overhead of making multiple connections and maintain a more efficient workflow.
WebSocket Protocol vs. HTTP: What’s the difference?
HTTP is a stateless request-response protocol. In layman’s terms, this means that each time a client sends a request to the server, it must include all of the information needed for the server to fulfill that request. The server then responds with the appropriate data, and the connection between client and server is closed.
A stateless protocol’s opposite, as the name implies, is a stateful protocol, where the server maintains information about each client connection and can use this info to process subsequent requests from that same client. Stateless protocols are generally simpler and more scalable than stateful ones since they don’t require the server to keep track of every client’s previous actions. However, they do have some disadvantages; one notable one is that without any persistent storage on the server side, it’s not possible to implement features like shopping carts or user login sessions.
For instance, if you’re shopping online and add an item to your cart, in order for that item to still be there when you come back later, the site needs some way to store that information somewhere — either on their own servers or in your browser via cookies. With HTTP being stateless by design, however, neither option is really available. As such, most web applications end up implementing workaround solutions like storing session IDs in the URL (called URL rewriting) or hidden form fields.
While the HTTP protocol is a great way to request or send data from a server, it wasn’t designed for bi-directional communication. This means that if you want to create an application where data flows in both directions (called “full duplex”), you have to make multiple requests, which can be inefficient.
WebSocket is a full-duplex protocol over a single TCP connection. This persistent connection makes communication much more efficient by eliminating the need for repeated handshake requests between client and server. WebSockets are especially well suited for applications where real-time updates are needed, such as stock tickers or chat clients.
Advantages of Using HTTP for Web Scraping
Now that the fundamentals are settled, how exactly does each one fare when used for web scraping specifically? What are their advantages and disadvantages?
HTTP is usually quick and easy to set up for web scraping purposes. Many websites already have an existing infrastructure in place to support HTTP requests, so there’s no need to build anything new. Additionally, because HTTP is a well-known protocol, there are many tools and libraries available that make it easy to work with. This makes working with HTTP much simpler than trying to scrape data using other protocols or methods. Since HTTP is so widely used, chances are good that the website you’re trying to scrape will support it. This increases your chances of being able to successfully gather the data you need without having to go through the hassle of setting up a new infrastructure yourself.
HTTP traffic is typically unencrypted, making it easier to intercept and view data being scraped. This transparency can be useful for debugging purposes or for understanding how a particular website works. Understanding the HTML structure of websites is integral in the preparatory phase of scraping, especially when using HTTP request methods since they aren’t very flexible. Meanwhile, when you hit a snag and need to perform some debugging, the more information you can find, the better.
HTTP connections are typically persistent, meaning that they can remain open for multiple requests/responses, which can speed up web scraping operations. Web scrapers can also take advantage of the keep-alive header to make multiple requests through a single connection, further reducing overhead. Additionally, by reusing connections and implementing caching mechanisms, web scrapers can minimize the amount of data transferred, which can potentially save bandwidth and time.
The structure of an HTTP request/response lends itself well to automated processing (i.e., parsing), which is often a necessary part of web scraping workflows. For example, if you are looking to scrape data from a website that requires some kind of login process, you may need to parse the HTML responses in order to extract relevant information (such as session cookies) that can be used in subsequent requests. Additionally, many websites use pagination controls (e.g., “next” and “previous” buttons) that also need to be parsed in order for the scraper to automatically navigate through all pages of interest.
HTTP-based APIs are widely used and well documented, making it easy to find information on how to access them programmatically for web scraping purposes. Because HTTP is so widely used, resources abound online for troubleshooting issues that you may encounter while web scraping. HTTP is excellent for both beginners and those not very technically inclined, as they can do DIY setup, scraping, and troubleshooting powered by just a little desktop research.
Disadvantages of Using HTTP for Web Scraping
That does it for the pros of HTTP. What about the cons? There are a few disadvantages of using HTTP for web scraping.
It can be difficult to set up and configure a web scraper to work with HTTP. This might seem contradictory to the first advantage of using HTTP listed above, but if you look closely, you’ll find the operative word “usually.” Using HTTP for web scraping is usually quick and easy to configure. But there are exceptions and situations where this isn’t the case.
Web scrapers typically work by making HTTP requests to web servers and then parsing the responses they receive back. The main issue with this approach is that it can be difficult to configure a web scraper to work correctly with all the different types of HTTP servers out there. For example, some servers may require authentication before they will return any data, while others might block requests from certain IP addresses or user agents.
HTTP is not as fast or as efficient as other methods, such as WebSocket. While HTTP is the most widely used protocol for web scraping, it’s not as fast nor as efficient as other methods such as WebSocket. This is because HTTP was designed for human-to-machine communication, while WebSocket was designed for machine-to-machine communication. As a result, HTTP requires more overhead than WebSocket and is therefore slower.
In addition, as mentioned earlier, HTTP can only scrape data from websites that support the protocol. On the other hand, WebSocket can be set up to scrape data from practically any website.
Because HTTP is a text-based protocol, it can be more difficult to parse and interpret the data that is returned from a web scraping request. When making a web scraping request, the client sends an HTTP request to the server. The server then responds with an HTTP response, which contains the requested data. The data is usually in the form of HTML or XML code. The problem is that the data isn’t always readily comprehensible. The data may not be well-formed or may be encoded in a way that makes it difficult to understand. In addition, different browsers and devices may use different character encodings, which can further complicate matters.
Advantages of Using WebSockets for Web Scraping
Okay, so what about WebSockets? What are the key advantages when using WebSockets for web scraping?
WebSockets generally allow for faster and more data retrieval than HTTP alone. The main advantage of using WebSockets for web scraping is the speed at which data can be retrieved. With HTTP alone, a separate request must be made for each piece of data that is needed. But with WebSockets, a single connection can be used to retrieve all the data that is required. This means that less time is spent waiting for data to be returned from the server, and more time can be spent processing it.
Another advantage of using WebSockets for web scraping is that it can provide a more efficient way of handling large amounts of data. With HTTP, each request requires its own connection to the server, which can quickly become overloaded if there are too many requests being made at once. WebSockets allow multiple requests to share a single connection, which reduces the load on the server and enables it to cope with large volumes of traffic better.
WebSockets can retrieve data in real-time as it changes. WebSockets provide a great advantage for web scraping compared to other methods. With WebSockets, you can retrieve data in real-time as it changes on the website, which is not possible with HTTP. As discussed earlier, WebSockets establish a two-way communication channel between the client and server, whereas with HTTP, the communication is only one-way. This two-way communication channel enables websites to push data to the client without having to wait for a request from the client first. This means that you can start receiving data immediately after opening a WebSocket connection without having to wait for an event on the website (such as someone clicking a button) that would trigger a response from the server containing new data.
In addition, because WebSockets keep this two-way connection open until it’s explicitly closed by either party (unlike HTTP which closes each connection after each request/response), they require less overhead and are more efficient than making multiple requests over HTTP. This makes them perfect for applications where you need to receive frequent updates of changing data in real-time — such as stock tickers or live sports scores — without putting unnecessary strain on your network or web server.
Web sockets do not put as much strain on servers. This is directly related to the above benefit. Unlike HTTP connections, each call is an independent HTTP request/response interaction. This can start to add up and put a lot of strain on a server if there are many clients making scraping requests at the same time. With WebSockets, however, there is only one initial connection between the client and server. From then on all communication happens over this single connection (in both directions), so it’s much more efficient and doesn’t require nearly as many resources from the server.
WebSockets are less likely to be blocked by measures such as rate limits or CAPTCHAs. WebSockets appear as regular traffic rather than as requests from a web crawler. This means that you can scrape websites without having to worry about being blocked by rate limits or CAPTCHAs. Many websites have measures in place that can block or slow down requests from web crawlers. These measures are often effective against traditional HTTP request-based scraping methods, but they’re less effective against WebSockets-based scraping.
WebSockets are less likely to be blocked by common measures for a few reasons. First, many scraping tools that use WebSockets are designed to mimic human behavior. It’s becoming increasingly harder for website administrators to detect and block them as technologies advance. In the same vein, WebSockets can be very effective against rate limiting, which works by limiting the number of requests that can be made from a given IP address in a given period of time. This can limit the effectiveness of traditional HTTP request-based scrapers, but it’s less effective against scrapers that use WebSockets because they tend to make fewer requests overall. Lastly, CAPTCHAs can be bypassed by WebSockets altogether — or they can be flagged to be delegated to human agents when necessary.
Disadvantages of Using WebSockets for Web Scraping
That settles the advantages of using WebSockets for scraping. What about the disadvantages? What are some WebSocket limitations you should keep in mind?
Not all websites support WebSockets. In order to use WebSockets for web scraping, the website must have implemented a server that can handle the WebSocket protocol. If a website has not done this, then it will not be possible to communicate with that site using WebSockets, and traditional HTTP methods will need to be used instead.
Furthermore, even if a website does support communication via WebSockets, there may be certain features or data that can only be accessed via HTTP and thus would require switching back and forth between protocols depending on what needs to be scraped from a given site.
Still, WebSockets is very widely implemented, so for the most part, if you’re keen on using it for web scraping, you’ll probably run into only a few exceptions.
More complicated to set up and use than HTTP alone. WebSockets are a much more complicated protocol than HTTP, and thus are likewise much more difficult to work with when it comes to web scraping. There are a few key differences between the two that make this so. First, WebSockets requires a full duplex connection, and this extra level of communication can complicate things when you’re trying to automate web scraping tasks.
Second, WebSockets use a binary format for their data payloads, whereas HTTP uses plain text. You need to be able to parse binary data in order to scrape websites using WebSockets, which again can add an extra layer of complexity.
Lastly, because WebSockets keep live connections open for long periods of time, you need to manage these connections carefully or else risk overloading your system resources.
WebSockets are generally slower than other methods of communication. “Slower” in this case refers to overhead. WebSockets require more overhead to set up and maintain a connection, and this infrastructural complexity (compared to the straightforward HTTP) can impact the speed at which you can scrape data from web pages.
Additionally, recall that WebSockets are often used for real-time applications where data is constantly being updated. That’s great on paper, but that also means each time you want to scrape data using a WebSocket connection, you will need to download the entire contents of the page again, even if only a small amount of new data has been added. So instead of the advantage you’re expecting, you may find your web scraping operation to take longer overall compared to using another method like HTTP polling, where you only download new content as it is added to the page.
Obviously, there are some disadvantages to using WebSockets for web scraping. As you can see, however, proper management and calibration can help mitigate these risks, for the most part.
So, What’s the Verdict?
So which one should you use in your web scraping activities? It really depends on your goals and what kind of data you’re trying to collect/extract.
HTTP is generally considered to be the best protocol for web scraping when it comes to static data because it was designed specifically for retrieving data from servers. HTTP requests are less likely to be blocked by website owners than other types of requests, and the data returned by the server will usually be well-structured. Overall, if you’re just looking to extract some static content from websites, then HTTP will suffice most of the time since it’s more widely supported and easier to work with in many programming languages compared to setting up proper WebSocket connections. However, there are some limitations to using HTTP for scraping dynamic content or content that updates in real-time.
In such cases, WebSocket is the better choice since it allows for two-way communication between client and server — excellent if you need near real-time updates or two-way communication with minimal latency. WebSocket facilitates server messaging without restriction on a single TCP connection, making it ideal for real-time requirements. Just take a look at some of its other applications, such as online multiplayer games, messaging services, and stock market websites. This also means it’s simply better suited for scraping dynamic data.
To wrap things up: the simpler and more generic the web scraping task, the better it is to stick to HTTP, in general. For more complex projects with websites that use dynamic data or key real-time requirements, WebSockets are preferable.
A meaningful caveat here is that due to websites generally becoming more complex and dynamic, HTTP on its own would be sufficient only for the simplest of web scraping projects. WebSocket use cases are increasing in number every day. So, by and large, WebSockets is a more effective go-to for web scraping, especially as you scale operations.
Why Is WebSocket Generally Better?
It’s generally known that WebSocket’s technical capabilities make it the better option de facto unless the web scraping task is so simple and compatible with HTTP that WebSocket is overkill. Why? Well, that boils down to WebSocket vs. HTTP performance.
- WebSocket is faster. Not only is using WebSockets faster per single request, but the more requests you send, the more pronounced the speed difference becomes. In one user test comparing HTTP to WebSockets, a single HTTP request took 107ms while a WebSocket request took 83ms. Going upwards from there, 50 requests took HTTP 5,000ms while taking WebSockets only 180ms. The finding rounds out to 10 requests per second for HTTP and 4,000 requests per second for WebSocket.
- WebSocket entails a generally lighter data transfer load. In the same user test, a single HTTP request needed 282 bytes of data, whereas a single WebSocket connection required just 54 bytes. As the number of requests grew, the difference shrank, but as you need more and more requests, WebSocket’s advantage in other areas grows instead, as you’ll see below.
- WebSocket performs better with more requests sent. In the same user test, the data load of concurrent connections favored HTTP over WebSocket at around 10 concurrent connections. Past 50 concurrent connections, however, WebSocket becomes much faster (around 50% faster), and this advantage is retained for even larger numbers of concurrent connections. The more you need, the better option WebSocket becomes.
Overall, WebSocket is generally faster than HTTP, can handle more requests per second, and requires less data to be transferred. Therefore, it’s usually the better option unless the web scraping task is very simple or is incompatible with WebSockets.
3 Considerations When Using WebSockets for Web Scraping
WebSocket connections can be used for web scraping by allowing a scraper to connect to a WebSocket endpoint and send and receive data. This is useful because it allows scrapers to bypass any blocking mechanisms that may be in place, such as rate limits or anti-scraping measures. Additionally, using a library that supports WebSockets makes implementation much simpler. For example, the websocket-client library for Python offers an easy-to-use interface for working with WebSockets in Python scrapers.
Note, however, that WebSockets should be used with caution when web scraping since they can introduce a significant amount of lag. When using WebSockets, it is important to consider the following:
- The number of connections that will be made to the server. Too many connections can bog down the server and cause delays in processing. Since WebSocket connections stay open until they are explicitly closed by the client or the server, a lot of resources (memory, CPU) can be used up on the server if there are a lot of connections open at the same time. If you’re going to be opening a lot of WebSocket connections as part of your web scraping software, it’s important to make sure that your server can handle the load. Otherwise, you run the risk of overloading your server and causing it to crash.
- The size of each message being sent. The WebSocket protocol specification states that the max message size is 64K. This means that when sending messages over a WebSocket connection, each message needs to be smaller than 64K or it will need to be split into multiple messages. If the messages are too large, they may not fit through the WebSocket connection and may cause an error. Additionally, larger messages will take longer to send because they have to be split into multiple packets and sent one at a time. And as larger messages take longer to send and receive, you’re looking at potential lag depending on the size of the message.
- The frequency at which messages will be sent. When scraping data, you want your web scraping software to receive messages at a high frequency so that you can get the most up-to-date information. If your web scraping software uses WebSockets, it will need to consider the frequency of message sending in order to function correctly, because if too many messages are sent too quickly, it can overwhelm the system and cause errors. Conversely, if not enough messages are sent, important data may be missed.
3 Best Practices When Using WebSockets for Web Scraping
Some best practices when using WebSockets in automated web scraping software include:
- Ensure that the WebSocket connection is properly encrypted and uses a strong protocol (such as WSS/TLS). When using WebSockets in automated web scraping software, it’s important to ensure that the connection is properly encrypted with strong protocols such as WSS/TLS to securely encrypt the connection. This will help to prevent third parties from intercepting any sensitive data that is sent over the connection. This is even more critical when using WebSockets that you might heavily automate, which means you won’t be able to constantly manually check the data it scrapes.
- Avoid sending sensitive data over the WebSocket connection that could be intercepted by third parties. Directly related to the first point: when sending (or scraping) data over a WebSocket connection, care should be taken to ensure that sensitive data is not included. This could include things like passwords, credit card numbers, or other Personally Identifiable Information (PII). If this data must be sent (or scraped) for some reason, it should be encrypted before being sent over the WebSocket connection.
- Monitor the WebSocket connection for errors and disconnections, and reconnect if necessary. This can be done by setting up a monitoring system that checks the status of the connection periodically. If a problem is detected, the system should attempt to reconnect automatically. This step is easy to forget once you set up the use of WebSockets. What this can potentially lead to, however, is a lot of potentially wasted time especially if you don’t consistently check in on scraping activity and manually see errors and disconnections.
In conclusion, WebSockets are a great tool for web scraping because they allow scrapers to bypass any blocking mechanisms that may be in place. However, they should be used with caution. Too many connections can bog down the server and cause delays, messages need to be of a reasonable size so as not to overwhelm the system, and care must be taken to ensure that important data is not missed by sending too few messages.
Using Proxies To Power Your Web Scraping
Aside from understanding HTTP and WebSockets, there is one critical tool you need to level up your web scraping: proxies. Proxy servers are critical when automating web scraping activities as they act as intermediaries between your computer and the internet, forwarding requests to the target website and returning responses to you.
Using a proxy has several benefits:
- Your identity is hidden when making requests. The proxy server makes requests on behalf of the user, so their IP address is hidden (some website block scrapers based on IP addresses).
- You can bypass restrictions placed on an IP address by a target website. If a website has blocked your IP address, then using another one will let you circumvent this restriction.
- Performance is improved by caching data and requests made through the proxy servers.
Finding the Right Proxies for Web Scraping
When it comes to web scraping, residential proxies are often the best option. This is because they provide you with IP addresses assigned to actual people by their internet service providers. This means that the IP addresses are valid and constantly changing, which can help your web scrapers avoid setting off any alarms. Plus, Rayobyte only sources residential proxies from ethical sources and works hard to keep downtime to a minimum.
If you’re looking for faster speeds, data center proxies are a great option. Traffic is routed through data centers with these proxies, resulting in quicker connections. The trade-off is that you’ll have fewer unique and nonresidential IP addresses, but they’re more affordable overall. If you’re doing any web scraping beyond small-scale tasks, then data center proxies can be an effective solution for your needs.
ISP proxies offer speed somewhere between residential and Data Center options while also providing increased anonymity due to the ISP association. When compared side by side, ISP proxies average around 30% faster than traditional Data Center options making them a solid choice for medium-level web scraping activities.
This primer on web scraping with HTTP vs. WebSockets is only a starting point aiming to show you the fundamentals and help you make better informed decisions for your scraping projects. Remember that each approach has its pros and cons. You’ll need to properly manage and set up the web scraping activities in a way so that you’re not only using the most appropriate choice for your needs but also that you’re maximizing the pros and minimizing the cons.
Whichever approach you choose, make sure you set up your scraper properly and take advantage of tools like proxy servers. Proxy servers will help you disguise your scraper and avoid being flagged by automated defenses that are common on the internet. Together with WebSockets, especially, proxy servers can bolster your web scraping activities so that you get more work done faster.
Need to empower your HTTP-based or WebSockets-based web scraping? A reliable proxy provider will most likely be needed. Rayobyte’s Scraping Robot can automate much of your workload. Explore our available proxies now.
The information contained within this article, including information posted by official staff, guest-submitted material, message board postings, or other third-party material is presented solely for the purposes of education and furtherance of the knowledge of the reader. All trademarks used in this publication are hereby acknowledged as the property of their respective owners.
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