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Have you ever wondered how websites and applications work behind the scenes? Have you ever heard the terms “client-side” and “server-side” and wondered what they mean? If you’re not so tech-savvy, chances are these terms sound like geek speak.
If you’d like to clear up the confusion, read on as we’ll break down the differences between them in this article. By the end of it, you’ll have a better understanding of how the web works, how the two could shape your web project, and, if you’re considering becoming a developer, which approach might be right for you.
Client-Side vs Server-Side: Side-by-Side Comparison
Client-Side | Server-Side | |
---|---|---|
Location | Runs on the user’s device (browser) | Runs on a remote server |
Functionality | Handles user interaction | Handles backend logic and data storage, processes user input, interacts with databases |
Security | Vulnerable to XSS, CSRF, and injection attacks | Vulnerable to injection attacks, broken authentication and session management, and DoS attacks |
Technologies | Uses HTML, CSS, JavaScript, jQuery, React, Angular, Vue.js, and Bootstrap | Uses PHP, Python, Ruby, Node.js, ASP.NET, Ruby on Rails, Django, and Express.js |
Performance | Depends on context. Code can be faster as it runs directly in the user’s web browser | Depends on context. Can handle heavy traffic and complex operations hence faster |
Client-Side vs Server-Side: What’s the Difference?
First things first, let’s define what we mean by “client-side” and “server-side.” Client-side refers to the part of an application or website that runs on the user’s device (often a web browser).
On the other hand, server-side refers to the part of the application that runs on the server and is delivered to the user’s device via the internet or other network connection.
The Client-Server Internet Model
Before we delve into the main differences between client-side and server-side development, we first need to understand the client-server model. The client-server model is the backbone of the internet.
In this model, user devices such as computers, phones, and smart devices communicate with centrally located servers to get the data they need.
These devices are considered ‘clients’ of the servers. Whenever you visit a website or use an app, your device sends a request to the server, and the server responds by sending the requested information back to your device.
The beauty of this model is that it allows for efficient communication and sharing of information between devices. It’s also critical to the functioning of websites and web applications.
Without it, we wouldn’t be able to browse the web or use the countless apps we rely on every day; or we’d be doing it in a totally different way.
Now that you understand the client-server architecture, let’s dive into client-side and server-side development.
Client-Side Development
If you’re an aspiring developer, client-side and server-side development are two approaches to building web applications and websites you will want to consider and understand.
Client-side development refers to front-end development, which means the code runs on the user’s device, such as their computer or phone. It’s responsible for what users see and interact with on an application.

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This includes everything from the layout and design to the user interface and interactive features. This means that client-side development focuses on creating a visually appealing and user-friendly interface that responds to user input, such as clicking a button or filling out a form.
Server-Side Development
As the name suggests, server-side development refers to back-end development, implying that the code runs through a server. Server-side development is used for anything that requires dynamic data, such as authentication, payment processing, and other interactions that require data to be processed and stored on a server.
Server-side development, therefore, focuses on handling data and logic behind the scenes. This includes processing user input, interacting with databases, and performing calculations. In essence, server-side development is responsible for making sure that everything works as it should and that data is stored and retrieved correctly.
Both approaches are essential for creating a fully functional website or web application. For instance, without client-side development, there would be no way for users to interact with a website or application. Without server-side development, there would be no way to store and process all the necessary data.
Security Considerations
One of the biggest considerations when developing for either the client side or the server side is security. Client-side code is generally more exposed and is visible or accessible to users and would-be attackers.
This makes it easy for malicious players to easily modify or steal the code, which can lead to security vulnerabilities and data breaches. Some of the most common vulnerabilities to keep in mind for client-side development include Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF).
Server-side development, on the other hand, is more secure because the code is not accessible to users. This means that even if malicious users try to modify or steal the code, they won’t be able to because it’s stored on a remote server.
Server-side code handles security by implementing authentication and authorization mechanisms, such as access control. Server-side code also sanitizes and validates input to prevent security vulnerabilities such as SQL injection and session hijacking.
Tools and Technologies Used in Client-side vs Server-side Development
Three major tools are essential for building the client side of modern web applications: HTML, CSS, and JavaScript. There is a whole bunch of other tools and technologies that build on top of these, such as React, Angular, Vue.js, Bootstrap, jQuery, and AJAX.

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On the server side, languages like PHP, Python, and Ruby have been popular choices for years. However, newer frameworks and technologies like Node.js, ASP.NET, Ruby on Rails, Django, and Express.js continue gaining popularity for their ability to handle scalability, complexity, and security.
Performance Considerations
Client-side code can be a bit of a hog when it comes to resources. It can sometimes result in slower performance because it’s running on the user’s device and, let’s face it, not everyone has the newest, shiniest computer or mobile device.
On the flip side, server-side development can result in faster performance because it relies on more powerful servers. Servers are built to handle concurrent tasks like processing data and running payments.
That said, client-side code can be faster in certain situations. Because it doesn’t have to send as many requests back and forth between the user’s device and the server, it can actually be quicker in some cases.
Let’s now look at some popular techniques for improving site performance that leverage the power of both client-side and server-side development: SSG, SSR, and SPA.
SSG and SSR
SSG and SSR are acronyms for Static Site Generation and Server Side Rendering, respectively. They are two different approaches to web development that allow for the creation of dynamic websites.
SSG involves generating a static website at build time and serving it to the user. This approach is typically used in client-side development, where the website or application entirely runs on the user’s device.
It can result in faster performance because there is no need to generate the page content on the server every time a user requests it. However, SSG can be limiting in terms of dynamic content, as the content is generated at build time.
Meanwhile, SSR is an approach that involves generating the website on the server at runtime and then serving it to the user. This approach can be more flexible in terms of dynamic content and it allows for more complex interactions. However, SSR can result in slower performance because each request must be handled by the server.
SPA
Have you ever visited a website that felt lightning-fast, even though it was packed with features and content, all without refreshing the page? Chances are, that site was built using a Single Page Application, or SPA for short.
SPAs are applications that allow the website to load all its content and functionality on a single page. This not only creates a smoother user experience but also improves site performance by reducing the number of HTTP requests needed to load the site.
However, building an SPA can be a bit more complex than traditional server-side development. With all the code and logic being handled on the client side, it’s important to ensure that the site remains responsive and doesn’t suffer from performance issues.
Client-Side vs Server-Side: 5 Must-Know Facts
- JavaScript is the most popular client-side programming language, with over 98% of websites using it.
- PHP is the most popular server-side programming language, with over 79% of websites using it.
- Ajax is a popular client-side technology that allows for dynamic and interactive web applications, bridging client-side and server-side.
- Client-side frameworks and libraries such as Angular and React are popular for building complex user interfaces.
- Server-side frameworks such as Ruby on Rails, Laravel, and Django can speed up development and provide a standardized structure for web applications.
Client-Side vs Server-Side: Which One Is Better? How Do I Know Which One Suits My Project Best?
So, you’ve got a project in mind, and you’re wondering which development approach to take. Before you decide which approach to take, you need to consider some factors. Where will the code run? What type of processes will be running on the frontend versus the backend? Will your site be dynamic or static? What programming languages will you be using?
If your project involves a complex web application that interacts with a database and requires backend logic, then developing for the server side is inevitable. Likewise, if you’re building a single-page application or a website that requires a lot of interactivity, developing for the client side may be the way to go.
Additionally, if speed is paramount and you won’t be serving dynamic content, then going “all–client” might make sense. This is because there won’t be any round trips requiring back-and-forth communication between users’ devices and your backend services (though this isn’t always true).
Once you’ve weighed all these factors, you’ll have a better chance to make the right choice for your project. So, you’ve got your head around the differences between client-side and server-side development. You may now be contemplating a career as a developer but you’re probably wondering which path to take. Check out our article on frontend and backend development for some insights.