Kotlin
Hacker ApprovedRanked 20 of 163 programming languages by recommenders
A concise, strongly typed JVM language with built-in null safety and smooth Java interop, though critics call it complex and Android-centric and say modern Java has caught up.
A concise, strongly typed JVM language with built-in null safety and smooth Java interop, though critics call it complex and Android-centric and say modern Java has caught up.
256 people gave an opinion
- recommend it
- 187
- criticize it
- 69
- approval share
- 73%
Recommended in 12 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Owned for 1.4 years
Median of the 3 owners who said how long they have had it.
Each square is one year.
Why it carries the badge
- 187 people recommend itNeeds 10 or more, met.
- 2.7 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 12 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Strong types and null safety
“It's a less clunky Java. The syntax is IMHO Ruby-level charming (for an OO-first lang), but with types that are quite a bit stronger than Java.”
Comment from 23 May 2026 in “PHP's Oddities” “Strongly typed, more concise than Java or Go (and probably Typescript), less likely to blow up at runtime than Typescript, epic tooling”
Comment from 11 May 2026 in “If AI Writes Your Code, Why Use Python?” “Kotlin is actually a pretty nice language, especially compared to Java. I love how they have null checking as a central feature.”
Comment from 6 Oct 2026 in “JetBrains reports revenue growth, net financial loss for 2025” - Comment from 27 Apr 2026 on Hacker News
- Comment from 8 Jul 2026 in “TypeScript 7”
- Comment from 15 Sep 2026 in “Java 27”
- Comment from 24 May 2026 in “dotNET (OK, C#) gets union types”
- Comment from 21 May 2026 in “Learnings from 100K lines of Rust with AI (2025)”
Far less verbose than Java
“It's a less clunky Java. The syntax is IMHO Ruby-level charming (for an OO-first lang), but with types that are quite a bit stronger than Java.”
Comment from 23 May 2026 in “PHP's Oddities” “Strongly typed, more concise than Java or Go (and probably Typescript), less likely to blow up at runtime than Typescript, epic tooling”
Comment from 11 May 2026 in “If AI Writes Your Code, Why Use Python?” “Kotlin is actually a pretty nice language, especially compared to Java. I love how they have null checking as a central feature.”
Comment from 6 Oct 2026 in “JetBrains reports revenue growth, net financial loss for 2025” - Comment from 4 Mar 2026 in “Voxile: A ray-traced game made in its own engine and programming language”
- Comment from 7 Dec 2025 in “Scala 3 slowed us down?”
- Comment from 11 Aug 2026 in “What's the best programming language for coding agents?”
Seamless two-way Java interop
“The two-way interop is one of Kotlin's advantages as it makes porting code from Java to Kotlin easier”
Comment from 24 Jan 2026 in “Kotlin's Rich Errors: Native, Typed Errors Without Exceptions” “Kotlin, in all honesty, is the first reasonable and very useful thing to come to the JRE ecosystem”
Comment from 10 Sep 2026 in “Shopify is moving from React Native back to Swift and Kotlin” “Kotlin has explicit interoperability with Java exactly to make it easy for Java devs to "upgrade"”
Comment from 6 Jan 2026 in “C Is Best” Multiplatform and official for Android
“However Kotlin has Google's as godfather, want to develop for Android with the official tools? Kotlin it is.”
Comment from 12 Jul 2026 in “Scarf has moved away from Haskell” “Kotlin has a better future than Scala, beyond the JVM, because papa Google has ensured it happens”
Comment from 1 Dec 2025 in “The Origins of Scala (2009)” “JetBrains has done a pretty good job of creating something that can fill many different niches”
Comment from 22 May 2026 in “Google's Antigravity Bait and Switch” - Comment from 12 Apr 2026 in “High-Level Rust: Getting 80% of the Benefits with 20% of the Pain”
What people warn about
Each mark is one comment
Too many features and abstractions
“It pretends to fix things that haven't been problems in Java for more than 10 years while introducing a layer of syntactic complexity that's completely unwarranted.”
Comment from 12 Apr 2026 in “High-Level Rust: Getting 80% of the Benefits with 20% of the Pain” “Only other language that I think gets close to rust ergonomics is Kotlin, but it suffers from having too many possibilities for abstractions.”
Comment from 3 May 2026 in “A Couple Million Lines of Haskell: Production Engineering at Mercury” “Kotlin is a terrible language for learning, as it has a lot syntactic shortcuts that are easy to mistake for magic”
Comment from 31 May 2026 in “Zig ELF Linker Improvements Devlog” - Comment from 6 Nov 2025 in “Ruby and Its Neighbors: Smalltalk”
- Comment from 30 Nov 2025 in “The Origins of Scala (2009)”
Ecosystem dominated by Android
“Kotlin is a nice language, though not nice enough to where I'd want to use it outside of Android.”
Comment from 22 Dec 2025 in “Build Android apps using Rust and Iced” “Maybe because my experience with Kotlin is restricted to Android, i didnt love that that much.”
Comment from 21 May 2026 in “Learnings from 100K lines of Rust with AI (2025)” “as nice as the language is, the ecosystem was ... so utterly dominated by Android development, that he said he wouldn't recommend using it again”
Comment from 7 Dec 2025 in “Scala 3 slowed us down?” - Comment from 24 Jul 2026 in “JEP 540: Simple JSON API (Now in Incubator)”
- Comment from 24 Jan 2026 in “Kotlin's Rich Errors: Native, Typed Errors Without Exceptions”
Modern Java has caught up
“It pretends to fix things that haven't been problems in Java for more than 10 years while introducing a layer of syntactic complexity that's completely unwarranted.”
Comment from 12 Apr 2026 in “High-Level Rust: Getting 80% of the Benefits with 20% of the Pain” “It has pioneered several important features, but now the big brother has implemented them slightly differently”
Comment from 6 Jan 2026 in “C Is Best” “Kotlin/JS is dead in the water, there's literally no reason to use it”
Comment from 25 Jan 2026 in “Kotlin's Rich Errors: Native, Typed Errors Without Exceptions” - Comment from 30 Nov 2025 in “The Origins of Scala (2009)”
Lacks checked error handling
“why is Kotlin implementing this in a non-JVM compatible way, instead of introducing checked exceptions with better language support?”
Comment from 23 Jan 2026 in “Kotlin's Rich Errors: Native, Typed Errors Without Exceptions” “Kotlins nice, mutability in the collections and nullable types are nice but they still lack some form of checked error handling”
Comment from 21 Jun 2026 in “Excessive nil pointer checks in Go”
Other programming languages people recommend
The four most recommended other programming languages, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
See all 163 programming languages, rankedWhat people said
40 of the 392 comments that mention it, newest first. Each links to the original comment.
“I can not find a reason to go back after Scala (which seemed to fail due to being indiscriminate) and especially Kotlin”
“Kotlin is actually a pretty nice language, especially compared to Java. I love how they have null checking as a central feature.”
“Kotlin solves more issues with the type system (smart casts, reified types, immutability by default)”
“Kotlin, in all honesty, is the first reasonable and very useful thing to come to the JRE ecosystem”
“Modern languages like Kotlin or Swift are pretty compact and don't really add a lot of bloat”
“requires paying tribute to its owners, only made relevant thanks to shipping in phones powered by a green droid”
“However Kotlin has Google's as godfather, want to develop for Android with the official tools? Kotlin it is.”
“Modern languages like TypeScript / Rust / Swift / Kotlin that have sum types are dramatically much nicer.”
“Typescript, Kotlin, Python and Ruby (via Sorbet or DryStruct) are all really easy to write all those data structures and code.”
“Kotlins nice, mutability in the collections and nullable types are nice but they still lack some form of checked error handling”
“Kotlin is a terrible language for learning, as it has a lot syntactic shortcuts that are easy to mistake for magic”
“Java’s Optional sucks compared to how C# (and Kotlin) implement support for nullable types.”
“Kotlin's combination of receiver lambdas plus syntactic sugar for calling higher-order functions make it an even better language to write DSLs in”
“It's a less clunky Java. The syntax is IMHO Ruby-level charming (for an OO-first lang), but with types that are quite a bit stronger than Java.”
“JetBrains has done a pretty good job of creating something that can fill many different niches”
“Maybe because my experience with Kotlin is restricted to Android, i didnt love that that much.”
“Kotlin is basically a Ruby (OO first with lots of FP goodness) with a serious type system.”
“Strongly typed, more concise than Java or Go (and probably Typescript), less likely to blow up at runtime than Typescript, epic tooling”
“Only other language that I think gets close to rust ergonomics is Kotlin, but it suffers from having too many possibilities for abstractions.”
“I absolutely loved it. With power of Kotlin I could produce maintainable code without one million null pointer validation”
“It pretends to fix things that haven't been problems in Java for more than 10 years while introducing a layer of syntactic complexity that's completely unwarranted.”
“you can compile Kotlin code for use in jvm, ios/ipados/macos, android, wasm/js, and native”
“Kotlin had other obvious advantages on Android like its thin standard library or the inlining of higher-order functions.”
“I favor a more functional style of programming and C# ends up making everything 5 times more verbose than Kotlin.”
“There was a small hype around Kotlin during 2016, because: cool lambdas! type inference! extension functions!”
“Kotlin/JS is dead in the water, there's literally no reason to use it”
“The two-way interop is one of Kotlin's advantages as it makes porting code from Java to Kotlin easier”
“Kotlin, well those behave as if ever the JVM would be one day rewriten in Kotlin, they have Android for that.”
“why is Kotlin implementing this in a non-JVM compatible way, instead of introducing checked exceptions with better language support?”
“It has pioneered several important features, but now the big brother has implemented them slightly differently”
“Kotlin has explicit interoperability with Java exactly to make it easy for Java devs to "upgrade"”
“Kotlin is a nice language, though not nice enough to where I'd want to use it outside of Android.”
“decreases verbosity so much that the interesting business logic is actually much easier to follow”
“as nice as the language is, the ecosystem was ... so utterly dominated by Android development, that he said he wouldn't recommend using it again”
“Kotlin has a better future than Scala, beyond the JVM, because papa Google has ensured it happens”
“Some of them even don't have any ideas how out of date their Kotlin "improvements" over Java are out of date.”
“It does a pretty good job of providing similar benefits as many Scala ecosystems, but providing approachability over purity.”
“Kotlin is not simple at all, it has a lot of keywords for strange and very specific features and corner cases”
“Rust and Kotlin are probably a little bit more "CSP-centric", since their channel interface is far less error-prone.”
“Where working in Swift and Kotlin feel like trying to navigate the many nuances of American football or cricket”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.