TIOBE April 2025 Index Shows Kotlin, Ruby, and Swift Falling While Flutter Gains Traction

TIOBE released its April 2025 programming‑language ranking, highlighting that the former top‑20 languages Kotlin, Ruby and Swift are now facing a hard time.

At the same time, historically "dinosaur" languages such as Delphi/Object Pascal, Fortran, Ada and COBOL are quietly climbing back into the top‑20.

For more context, see the March 2025 ranking article titled "Old‑school languages make a strong comeback because their developers retired".

Kotlin, Ruby and Swift, which once held stable positions in the TIOBE top‑20, are now losing attention; Ruby sits at rank 24, Kotlin at 25, and Swift at 26.

The decline of Kotlin and Swift is attributed to their focus on single mobile platforms (Android for Kotlin, iOS for Swift), while cross‑platform solutions now offer better productivity.

Developers are increasingly adopting Google’s open‑source Flutter framework, which uses the Dart language to build iOS and Android apps from a single codebase, dramatically improving development efficiency and reducing costs, especially for startups and MVPs.

Flutter’s main advantage is its cross‑platform capability, allowing developers to write code once in Dart and deploy to both mobile platforms without separate native development.

Ruby’s situation differs: it competes with Python and Perl, but Python’s dominance as a universal language with a rich ecosystem squeezes Ruby’s market share.

In web development, Ruby also faces strong competition from PHP and Node.js, leaving it with only a small niche.

PHP has risen back to rank 13, reaffirming its position as the leading language for website development.

An example is a solo developer who achieved financial independence by rapidly delivering multiple projects using PHP.

Overall, the top‑20 languages now account for 83.56% of the market share, indicating a conservative market where developers prefer mature technologies.

The current top‑10 languages are: Python, C++, C, Java, C#, JavaScript, Go, Visual Basic, Delphi/Object Pascal, and SQL.

Ranks 11‑20 are shown in the following chart:

Ranks 21‑50 are illustrated here:

Ranks 51‑100 include a long list of languages such as ActionScript, Algol, Alice, Apex, APL, Applescript, CHILL, Clipper, CLIPS, Clojure, Curl, Eiffel, Elm, Erlang, F#, Forth, Groovy, Hack, Icon, Inform, Io, JScript, LabVIEW, Ladder Logic, Modula‑2, Mojo, MQL5, NATURAL, Nim, Oberon, OCaml, Occam, OpenCL, PL/I, Q, Racket, Raku, Ring, RPG, S, Scheme, Smalltalk, SPARK, Stata, Tcl, Transact‑SQL, Vala/Genie, VHDL, Wolfram, XSLT.

Historical ranking curves (1988‑2025) are displayed below:

A "Programming Language Celebrity" list (2003‑2024) is also provided:

The TIOBE index is compiled monthly based on the number of engineers, courses, and third‑party vendors worldwide, using data from search engines and technical communities such as Google, Baidu, and Wikipedia.

While the data reflects current trends and can guide learning and career decisions, each language has its own suitable scenarios, so the rankings should not be over‑emphasized.

Reference link: https://www.tiobe.com/tiobe-index/