The Most Popular Programming Languages

Knowing a programming language is essential for many high-tech jobs, such as those in the fields of data science and software engineering. A question people often ask when considering a new career that involves technology is “which programming language(s) should I learn?” 

Choosing a language is a big decision: you will likely spend months learning a programming language and years refining your skills. Crucial factors to consider when choosing a language include whether it is used and whether that language will help you get a job. Languages in greater demand are more likely to offer more lucrative job prospects. 

Another important factor is whether the language has a strong community from which you can source answers to questions or seek help. The more popular a programming language is, the more likely you are to find the resources and support network you need to successfully master the language you have chosen to learn. 

With these factors in mind, we have done some research to find the most popular programming languages today. Using our research, you can make a more informed decision about which programming language may be right for you.

In this guide, we break down the most popular programming languages into three categories:

• Job openings that mention a particular language, based on job openings data from LinkedIn.
• Use on GitHub, according to data from GitHub on the number of repositories that use the languages we study.
• Community activity, based on data collected from Stack Overflow’s question pages.

We believe the categories we have chosen to study will give us greater insight into the multifaceted popularity of various programming languages.

Key Findings on the Most In-Demand Programming Languages

We looked at LinkedIn, GitHub, and Stack Overflow to learn more about in-demand programming languages. We found:

• Based on job openings on LinkedIn, the programming languages most sought-after by employers are C, SQL, Python, Java, and R.
• On GitHub, Java, JavaScript, HTML, Python, and PHP are the most used programming languages.
• On Stack Overflow, JavaScript, Java, Python, C#, and PHP are the programming languages most often mentioned. 

In this report, we dive deeper into the above statements, with reference to the data behind our findings.

Methodology

To conduct this report, we first had to come up with a list of languages to study. After some research, we determined that the top 20 languages in the TIOBE Index would be a good indication. This data source tracks programming language popularity in terms of search activity, and so gave us a good starting place. We checked the TIOBE Index on March 24th, 2021 and made a list of languages to study.

We excluded Classic Visual Basic, for which data was not readily available for any of our categories. We added HTML and CSS, which we believe are important programming languages but were not included in the TIOBE Index.

We then manually collected data on each of the programming languages in our study. Our data from LinkedIn and Stack Overflow was collected between March 24th and March 25th, 2021. The data from GitHub was collected on April 8th, 2021.

Each of our rankings lists the top 10 languages that meet our criteria (e.g., top programming languages by jobs on LinkedIn).

Without further ado, let’s take a look at the most popular programming languages.

Top Programming Languages by Job Openings

“Will this programming language help me get a job?” is a common question asked by beginners to coding and even seasoned developers who want to advance in their careers. This question is so widely asked because many people see programming as a gateway to a new career with long-term job security.

To find which programming languages have the most active job openings, we went to LinkedIn. We chose LinkedIn as our data source for job openings because the platform is widely used to post technical job ads, thus giving us a large dataset with which to work. LinkedIn also allows one to search for jobs based on programming languages rather than job titles.

We have focused solely on programming languages (e.g., C#, Python) rather than job titles (e.g., data scientist), since particular professions involve various skills and are thus not representative of the popularity of a single language. Our data only accounts for US job openings.

We collected data using a filter on LinkedIn’s website that shows jobs posted in just the last month. This filter decreases the likelihood that our data includes dormant job posts, so our data is more likely to be reflective of how many jobs were open at the time of conducting this study. Our data was collected on March 25th, 2021.

Based on the data we collected, here are the programming languages associated with the most job openings in the United States:

Our analysis shows that C, SQL, and Python skills are mentioned the most in LinkedIn job openings, and are thus the most in-demand programming languages at the moment.

Each of these languages is used in many different tech careers. For instance, C is used by game developers, graphics programmers, software engineers, and more. SQL is used by data analysts, data scientists, software engineers, web developers, and so on.

We believe the role these languages play in many modern applications contributes to their popularity, too. For instance, JavaScript is featured on many modern websites and powers features from interactive image carousels to the front end of payment forms. SQL is used widely for data storage, which is something that comes up in many fields from web development to software engineering to data analysis and visualization.

However, it is worth noting that not some languages will not open up job opportunities on their own. For instance, one would need to learn both HTML and CSS to become a web developer, and perhaps JavaScript. Non-web jobs may also require knowledge of more than one language. For instance, some R jobs may require a knowledge of Python. These two languages are used together in a wide range of data science settings.

All in all, it should come as no surprise that there are many job opportunities available for all ten of these programming languages, given their versatility, their extensive histories, and the growing influence of technology in our lives. C, SQL, and Python are the most in-demand programming languages in the job market, but all ten are in high demand.

Programming Language Popularity by GitHub Repository Activity

Next, we wanted to find a way to see which languages were widely used. For this, we turned to GitHub, which is widely used by developers for business and personal projects.

On GitHub, developers can find boilerplate projects with which they can work, open source libraries to use in their code, and other projects that may include code to help them solve a problem. Also, GitHub lets developers file issues with repositories, which makes it easy for people using code from a particular repository to find a solution to any issue they may encounter. 

Because GitHub is such a widely used resource by developers, we thought we would take a look at how many repositories there are for each language. A repository refers to a project hosted on GitHub. The more repositories available in a particular language, the more likely you will be able to find an example project or an open source library that will be helpful as you work with a language. 

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We used the GitHub “language:” filter on its search bar to determine how many open source repositories are associated with a particular language. Using this information, we can get a better idea of the popularity of various common programming languages.

Here are the most popular programming languages by GitHub repository activity:

Seven of the ten languages above also appeared on our job postings chart. This shows there is a strong correlation between the code written on GitHub and the most in-demand skills on the current job market.  We expected this correlation because the languages that pay well are also those that have many practical applications. For instance, C++, which appears on both lists, is used for game development, web development, and systems programming, in both professional and personal contexts.

Java, JavaScript, and HTML are the most popular programming languages used on GitHub. However, all ten languages we studied are incredibly popular. Even C, the language at the bottom of our ranking, was featured in 803,461 repositories, which indicates heavy usage.

Most Popular Programming Languages by Community Activity on Stack Overflow

Learning a programming language is tough. You will experience many ups and downs in the course of your training, even if you already have some coding or programming experience. Some days you will be stuck on a bug that is hard to fix. Other days you will have a breakthrough and feel proud of your progress.

Having a strong community you can consult arguably makes it easier to learn a programming language. This is because you are more likely to be able to find a good answer to your coding questions in a timely manner. Thus, we decided to look for ways to measure community activity for common programming languages.

While programming language communities are often distributed across platforms, we think Stack Overflow is a good barometer for community activity. Stack Overflow is a popular destination where developers share problems and solutions to questions.

We looked at Stack Overflow and took note of how many questions were associated with each language. We then used this information to create a chart ranking the most popular languages by total number of questions.

Our data accounts for all of the questions written on Stack Overflow since the platform was introduced. Stack Overflow was launched on November 15th, 2008. We believe looking at all questions written is a more useful metric than recent threads because many historical threads that are no longer active may still be useful. Even when languages are updated, most updates are not significant enough to render previous questions useless. Also, many people may use legacy codebases and thus rely on documentation for older versions of a tool.

Here are the ten most popular programming languages we identified based on community activity on Stack Overflow:

We can see that all of the top programming languages on our list are extensively discussed on Stack Overflow. The languages most often discussed on Stack Overflow are similar to the skills most often mentioned in job openings.

Nine of the ten skills in our “most popular programming languages by job openings” classification are featured in our community activity chart above. The only language not carried over is C. With that said, C++ and C#, which are both based on C and used in many modern software development applications, are present on both charts. This does not suggest that C is not popular, but rather that C is not as popular as C++ and C on Stack Overflow.

The more questions one finds on Stack Overflow, the more likely there is to be a similar question to one that you have. Scattered among the more than two million questions on JavaScript, for instance, you are likely to find documentation on errors you encounter or answers to your own questions. Or you might find code snippets that you can use in your work.

Even if a question you have is not documented, the massive number of questions indicates there are many developers on the platform, some of whom may be able to help you with your question. A larger community means you should be able to find an answer to your query or get help debugging an issue in a shorter period of time. The more users and activity there are for a particular programming language, the more likely you are to have success learning it. 

In conclusion, JavaScript, Java, and Python are the most popular programming languages discussed on Stack Overflow. However, as we saw with GitHub activity, even the language at the bottom of our ranking is still incredibly popular. R is tagged in 394,286 threads.

Most Popular Programming Languages Review

Through our research, we have found that there are significant overlaps between job openings, usage in the community, and community questions and answers. These categories are indicated by data from LinkedIn, GitHub, and Stack Overflow, respectively.

The languages that came up in all of our top 10 programming language rankings were (in no particular order):

• JavaScript
• HTML
• C++
• C#
• CSS
• Python
• Java

Notably, all of these technologies are used in modern web development to some extent. Python is actively used for backend web development, but also has other uses. This data shows that web development programming languages are incredibly popular and employers are actively looking for people with web development skills.

However, many of these languages are used for a wide variety of purposes, including Java, C++, C#, and Python. You will see both of these languages used in games development, systems programming, software development, and other settings. This suggests that web development does not hold a monopoly on popular programming languages, though that field’s heavy representation on this list remains noteworthy. 

Other languages from the 21 we studied did not come up in any of our top 10 rankings. These were (in no particular order):

• Assembly
• Go
• Delphi
• Groovy
• Perl
• MATLAB
• Objective-C
• Swift

Thus, we can say the above languages are less popular than the others we studied, based on the information we collected from LinkedIn, GitHub, and Stack Overflow.

There is no single factor responsible for the six languages above not coming up in any of our top ten rankings. One contributing factor, however, is that some of the above languages have been replaced by more modern alternatives. For instance, Perl used to be very popular for web development, but it has since been overtaken by Python. Objective-C was popular when iOS used Objective-C, but now iOS uses Swift, which we suspect will eat into the popularity of Objective-C.

We cannot definitively say that any one object oriented programming language is better than another. Every programming language can be applied in different situations. Learning Python is not as useful as learning HTML, CSS, and JavaScript if you plan to become a front end web developer, for instance. With that said, the information we have collated will give you a general idea of which languages are popular in 2021.

Using what we discovered about the job prospects and community activity for various programming languages, you will be able to make a more informed decision about which language to learn.