Even though both PHP and Node.js can manage apps of any complexity, they are built around different concepts and architectures. If you are an app owner choosing between these two environments, you should be aware of their major advantages and limitations.

Node.js and PHP are two very popular web development solutions. PHP, a scripting language created by Rasmus Lerdorf in 1994, was one of the top languages of the Web 1.0 era. The eloquent manifestation of the PHP success are CMS (Content Management Systems), such as WordPress, Joomla or Drupal that power millions of blogs and web portals. Node.js is a representative of a younger web development generation. Unlike PHP, Node.js is not a language, but a runtime environment that uses JavaScript for the server-side application development. Launched in 2009, Node.js has demonstrated the power of JavaScript in building event-based, data-driven, I/O-heavy applications for the Web 2.0 era.

Node.js Pros

1. Fast Server-Side Solution

Node.js leverages JavaScript event loop to create non-blocking I/O (Input/Output) applications that can easily service multiple concurrent events. Using JavaScript built-in asynchronous processing, one can create highly scalable server-side solutions that maximise the usage of a single CPU and computer memory while servicing more concurrent requests than conventional multithreaded servers. This functionality makes Node.js a great fit for asynchronous, data-driven applications and heavy I/O-bound workflows such as RTAs (Real-time Applications) or SPAs (Single-page Applications), where Node ensures excellent runtime performance.

2. One Language Across the Stack

Many popular client-side frameworks such as Ember, React and Angular are written in JavaScript which is the main language of modern browsers. While using Node.js server-side, you have all the benefits of one scripting language across your application development stack.

Having the same language both on the front- and the back-end is excellent for maintainability of your application and coordination between members of your team because both frontend and backend developers work with the same JavaScript data structures, functions, idiomatic expressions, and language conventions. All that contributes to faster application development, bug fixing, and coordination within your engineering team.

3. Flexibility

Node.js comes with few hard dependencies, rules and guidelines, which leaves the room for freedom and creativity in developing your applications. Being an unopinionated framework, Node.js does not impose strict conventions allowing developers to select the best architecture, design patterns, modules and features for your next project. With Node, your engineering team will have access to thousands of modules for any imaginable purposes via the NPM repository.

Node.js Cons

1. Less Efficient in Handling CPU-intensive Applications

Node.js is a single-threaded and event-based environment that is not as good in handling CPU intensive operations, such as generating or editing graphics, audio, and video as in managing concurrent requests. When processing large files or doing operations with graphics, Node.js applications might become unresponsive and sluggish. Whenever you are thinking about graphics apps, a multi-threaded server environment is a better option than Node.js.

2. Lack of Maturity

Along with stable core libraries, like HTTP or Crypto, Node repository provides access to a bunch of third-party modules developed by the community. This ecosystem of modules is still fairly immature. It’s hard to assess the quality of a particular module before application deployment. Moreover, subtle bugs and version inconsistency may creep into applications making it difficult to maintain them. The ease of publishing your own packages paired with the lack of a reliable mechanism of module’s approval means that you should pay more attention while selecting packages to make sure that they had a recent activity such as bug fixes and updates.

PHP Pros

1. Rich Code Base

PHP has a powerful code base that includes popular platforms for building websites (WordPress, Joomla, Drupal) and web development frameworks (Laravel, Symfony) that enable Rapid Application Development. CMS (Content Management Systems), such as WordPress, make it easy to deploy a blog or an e-commerce site in a matter of minutes and allow non-developers to customise them according to their needs. Also, there are numerous PHP applications offered by hosting platforms such as the cPanel which can be installed in one click. A breadth of open-source solutions written in PHP and a strong community behind them means everything you need for your application development is at your fingertips.

2. Portable Solution

PHP is a highly portable application development solution. It can be run on almost any server (Nginx, Apache) and every platform (Windows, Linux). This means that you have to write your code only once and run it anywhere.

At the same time, there is a wide hosting support for PHP. A number of hosting providers offer shared hosting options for PHP, but you need a virtual server with SSH access to run Node.js applications. Therefore, PHP integration and deployment is easier for small companies or individuals who have can run and manage their applications without any knowledge of SSH (Secure Shell), console commands, and Linux server technologies which are the preferred option for Node.js.

3. Designed for the Web

Unlike Java or Python and other general-purpose programming languages, PHP was designed specifically to work well on the Web. That’s why it includes all needed functionality to manage HTML, servers and databases (MySQL in particular). With a comprehensive server-side solution like PHP, there is also no need to bother about JavaScript in the browser since all pages can be easily generated and rendered on the server. This is useful if you want to avoid overloading of the client side. At the same time, heavy server-side rendering and regular requests to the server to generate and render pages might not be a good option for Single Page Applications (SPAs) with rich client-side functionality for which JavaScript is frequently a better option.

PHP Cons

1. Inefficient Separation of Concerns (SoC)

PHP is not a great fit for the implementation of MVC (Model-View-Controller) approach that prescribes clear Separation of Concerns (SOC) between data, behaviour and representation. MVC is a de facto best practice in web development that ensures readability, maintainability, and scalability of web applications. In PHP, however, there is a tendency to mix HTML and language syntax inside HTML files, which quickly results in the poorly maintainable code where views and business logic are not separated. As a result, it’s hard to extend PHP applications with new functionality and manage applications with a large code base.

2. Outdated Client-Server Model

PHP follows the classical client-server model where every page request initiates the application, database connection, configuration parameters and HTML rendering. This makes PHP somewhat slower in comparison to Node.js application that runs permanently and needs only to initialise once. Thanks to these features, Node.js is more suitable for state-of-the-art HTML5 features, AJAX and WebSockets. The problem may be handled in PHP via Memcached; however, this is not a standard feature of the PHP language.

So, How to Make the Right Choice?

As you have seen, both Node.js and PHP have their good and bad parts. If so, how do we make the right choice? It’s possible if we leverage our knowledge of both environment’s architectures and ecosystems.

In particular, asynchronous and event-based architecture of Node.js makes it a great fit for RTA (Real-Time Applications) such as instant messaging and collaborative apps (drawing and video conferencing) in which many requests are happening concurrently and where data is frequently shuffled back and forth from the server to the client.

Node.js support of server-side events and WebSockets makes it easy to implement pub-sub (publish-subscribe) architectures used in RTAs and quickly update the view on the client side. The same features make Node.js suitable for applications that process data from IoT (Internet of Things) and Single Page Applications (SPAs) that involve highly flexible, dynamic and heavy client-side functionality.

With Node.js, it’s also easier to implement web services in which the server-side functions as a REST API that provides the connection between the client and a database and where the speed of CRUD operations and asynchronous processing is of great importance.

In its turn, PHP is a good choice for a standardized solution such as a blog, news site, landing page or web portal. With such CMS (Content Management System) as WordPress written in PHP, you can create stable and customizable blogs without too much coding. If you need more customization, WordPress provides a well-documented API to change application’s structure, presentation, plugins, etc.

As a bonus, WordPress community has created thousands of customizable themes that open infinite opportunities for web designers. Whenever time is a consideration, you can develop almost any application ranging from a blog to an e-commerce site with CMS and other tools written in PHP. PHP is also a better choice if hosting support is the issue. If your client wants a shared hosting service instead of a full-fledged virtual cloud instance, PHP provides more flexibility in integration and deployment.

So, when choosing between Node.js and PHP, you should definitely consider what type of application you are going to build, what are the hosting requirements of your client, and what is the speed of development. If your client is looking for a standardized solution with an extensive hosting support, you should consider using PHP. On the other hand, Node.js is a better option for RTAs (Real-time Applications) such as chats, collaboration apps and SPAs (Single-page Applications).