Tiobe Index: C# is the programming language of the year 2025

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The IT consulting firm Tiobe has named C# the programming language of the year 2025 in the controversial Tiobe Index. Tiobe analyzes the twenty most popular programming languages on the web monthly and awards the title in January for the preceding year. The decisive factor is the language with the largest year-on-year gains. After 2023, this is the second time C# has received the title within three years.

According to Tiobe, C# recorded the strongest increase in ratings in 2025. The operators attribute this to profound changes in the language in recent years. C# adopted new concepts early on, breaking free from its exclusive Windows binding and evolving from a proprietary Microsoft product into a cross-platform open-source language.

Java and C# in a head-to-head race

In the enterprise software market, Java and C# have been in a close race for years. Tiobe sees no clear winner yet. Java remains widely used but is facing increasing pressure due to its comparatively extensive boilerplate code and its association with Oracle.

Shifts in the Top 10

There were also movements within the Top 10 in 2025. C and C++ swapped places. While C++ has changed significantly in recent years, according to Tiobe, some major innovations like the module system have so far only found limited practical application. C, on the other hand, continues to benefit from its simplicity and speed, especially in the growing market for small embedded systems. Rust reached a new high with 13th place but has not yet been able to establish itself permanently in this environment.

Winners and Losers of the Year

Among the surprising winners is Perl. The language improved significantly from 32nd to 11th place, thus returning to the Top 20. R is also back in the Top 10, driven by the continued growth in data science and statistical data analysis.

On the losing side, Tiobe names Go, among others, which permanently fell out of the Top 10 in 2025 – Programming Language of the Year 2016. Ruby also slipped out of the Top 20 and, according to the index operators' assessment, is unlikely to return soon.

Outlook for 2026

Tiobe also takes a cautious look ahead. TypeScript could make the leap into the Top 20 for the first time in 2026. Furthermore, Tiobe sees potential in Zig, which moved from 61st to 42nd place in 2025, thus moving closer to the Top 30.

When calculating the index, the operators want to evaluate the number of engineers, courses, and service providers using a programming language. Tiobe collects this through queries on various internet search engines. The operators themselves point out that the index should primarily be used to check the currency of programming skills and for strategic decisions when selecting programming languages for new projects.

Further information can be found in the article on the official Tiobe website.

(mdo)