You might think there’s a one-word answer to the question: What is the fastest programming language? But actually, there’s a lot of technical nuance when it comes to speed and programming. For starters, faster is not necessarily better — it really depends on the use case. (But we’ll get to that.)
Here, we lay out exactly what makes a programming language “fast,” why it matters, and how you can get started learning some of the fastest programming languages out there.
What makes a programming language fast?
The key feature of a programming language that determines that a language is fast is whether it is a compiled or interpreted language. Compiled languages — like Lisp, C++, Go, Rust, and Swift — must be converted to machine code (see Assembly below) that talks directly to the hardware. Interpreted languages like Python, JavaScript, Ruby, and PHP run by converting your source code on the fly into machine code as it is running. Because this conversion process happens while the code is running and adds overhead, interpreted languages are slower than compiled languages.
There are a couple of other factors that can determine the speed of a language. Take Java and C# — these languages are both compiled and interpreted. However, instead of being compiled to Assembly code, they are compiled to bytecode. The compiled bytecode is interpreted to run in a virtual machine that is optimized to speak directly to the hardware. You can think of bytecode as Assembly language for the VM. This makes these languages faster than a language like JavaScript, which converts text-based source code directly into machine code.
Another factor is whether it’s a statically-typed language or a dynamically-typed one. Statically typed languages determine the types of all variables when the language is compiled, and dynamically typed languages check the type of variables while the code is running. This real-time type checking comes with some overhead, making dynamically typed languages slower than statically typed languages.
What are the fastest programming languages?
The fastest programming language interacts directly with the machine. Let’s take a look at some of the fastest languages you might encounter, and what they’re used for.
Assembly
Assembly language is not really one specific language. It is just the name given to any low-level programming language that communicates directly with a computer’s hardware. This means that Assembly for your laptop will be different from the Assembly for your cell phone, because they have different CPUs that require different instructions. Usually, only developers who work directly with hardware or create programming languages use Assembly.
Lisp
Lisp is one of the earliest programming languages and is now over 60 years old. There have been many varieties of this language, and many other programming languages have used some of the same features as Lisp. Clojure, for example, is a modern Lisp dialect implemented for the Java Virtual Machine, but Clojure is not why Lisp is on this list. Common Lisp compiles directly to Assembly language, which means that the code you write in Lisp will be Assembly when it runs as an executable. Lisp is still used today, but you will most often find it as Clojure rather than Common Lisp.
C/C++
C and C++ are also compiled languages. C is a simple, procedural programming language that was initially developed in the early 1970s and is still widely used today, mainly in embedded applications, because of its speed and small size. C++ is a language that extends C and adds object-oriented features. Because of this, it has replaced C in many applications. C++ is used in situations where performance is important, like 3D video game development and operating system development.
Go
Go, also known as Golang, is a programming language developed by Google. It compiles to Assembly like most of the other languages here, but it has more modern features, simpler syntax, and is easier to write than the long-time leader of fast programming languages, C/C++. Golang is often used in network servers and distributed systems where its speed can add more performance to these systems.
Rust
Rust is another compiled programming language that is also a safer alternative to C/C++. It focuses on speed, memory safety, and parallel processing and is often used in game engines, browser components, and VR simulation engines where speed is a priority.
C#
C# is a language, like Java, that first compiles to a virtual language and then is interpreted by a VM. This gives it the features of an interpreted language while adding some speed. C#, developed by Microsoft, is easy to learn, and has many third-party libraries that make development quicker and easier. Like C++, C# is versatile, used for creating desktop applications, video games, and web services.
Java
Java compiles to bytecode which is then interpreted by the Java Virtual Machine. It was one of the first programming languages to do this, which is why it quickly became (and remains) popular. Using a VM means that a Java application can be moved from one operating system to another with no changes to the code as long as there is a version of the JVM for the operating system available. This cross-platform feature combined with its speed makes Java a popular language for many applications, including web development, desktop development, game development, mobile app development, and much more.
Swift
Swift is a modern programming language developed by Apple that compiles to Assembly code. It was designed to replace the older Objective-C language. It’s used to develop your favorite Apple products, like Apple TV, the Apple Watch, and iPhones and iPads. Swift is now the most popular language for Mac OS X and iOS development, but it is also cross-platform and is starting to see use in other applications.
It’s not always about being fast
While speed can be important when considering a programming language to use, there are plenty of other factors to think about. When you are writing code, there will be times that other features of a programming language are more important than being fast. After all, if speed were the top priority for every project, programming languages not on this list wouldn’t have much use, and we’d be writing Assembly code. However, the truth is that some of the most popular programming languages aren’t even on this list.
Speed is relative, and many times, a program in C++ will be ten times faster than a program in Python, but it just doesn’t matter in that specific application. After all, if an operation finishes in .001 seconds instead of .01 seconds, can you really tell the difference? The difference, though, will matter if you have to perform that same operation thousands of times in a loop.
A lot of the time, speed of development matters a lot more than the speed of execution. A slow program can be scaled to improve its performance by throwing more resources at it, and computing resources are cheap compared to paying for more development time to write code in a low-level language that is more complex to write. Slower programming languages are popular because they are easier to write, have a wealth of third-party libraries available, and can be deployed quicker. All of this speeds up development time.
Learn more
While the speed of a programming language is not always the most important feature, there are definite benefits to being quick. Fortunately, you can start learning these today with our self-paced online courses. Here are some great places to start:
- Learn C++
- Learn Go
- Learn C#
- Learn Swift
Once you familiarize yourself with these coding languages, you’ll be able to use these in a wide range of roles and career opportunities.
