Best js_of_ocaml Alternatives in 2026
The top js_of_ocaml alternatives are Babel, SWC and Kotlin/JS: 15 code transpilers our editors would look at instead of js_of_ocaml, in our ranking order.
js_of_ocaml: A focused OCaml-to-JavaScript compiler with browser bindings and Dune support. Where it falls short: requires compiling programs with OCaml bytecode tools first.
Switching from js_of_ocaml? For most code transpilers buyers the best js_of_ocaml alternative is Babel, built for javaScript projects needing flexible transforms. Fable offers the most source languages (1 languages).
Why People Look for a js_of_ocaml Alternative
- Requires compiling programs with OCaml bytecode tools first
- Its scope is centered on OCaml-to-JavaScript workflows
- Support channels are documentation and community
- No syntax-version conversion — 4 of the alternatives below have it
- No intermediate output — 5 of the alternatives below have it
Quick Picks by What You Need
- Best overallBabel9.3
JavaScript projects needing flexible transforms
Visit Babel - Best free optionBabel9.3
Has a free plan
Visit Babel - Most source languagesFable8.1
1 languages
Visit Fable - Best for syntax-version conversionBabel9.3
Syntax-version conversion (js_of_ocaml: no)
Visit Babel
All 15 js_of_ocaml Alternatives, Ranked
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
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Best forJavaScript projects needing flexible transforms
- Better than js_of_ocaml:
- Syntax-version conversion
- Intermediate output
- API access
Flexible ECMAScript transforms with CLI, Node.js APIs, and browser compilation.
- Syntax-version conversion
- Intermediate output
- API access
9.3/10★★★★★Visit Babel -
Best forFast JavaScript and TypeScript build pipelines
- Better than js_of_ocaml:
- Editor score 9.2 vs 7.2
An open-source compiler with minification and bundling for JavaScript and TypeScript workflows.
9.2/10★★★★★Visit SWC -
Best forKotlin teams targeting browsers or Node.js
- Better than js_of_ocaml:
- Syntax-version conversion
- Intermediate output
- Editor score 8.8 vs 7.2
A free Kotlin-to-JavaScript toolchain for browser and Node.js projects.
- Syntax-version conversion
- Intermediate output
- CLI access
8.8/10★★★★☆Visit Kotlin/JS -
Best forPython projects needing C or C++ extensions
- Better than js_of_ocaml:
- API access
- Editor score 8.7 vs 7.2
An open-source compiler for Python projects that need native C or C++ extensions.
- API access
- CLI access
8.7/10★★★★☆Visit Cython -
Best forJava teams targeting JavaScript or WebAssembly
- Better than js_of_ocaml:
- API access
- Editor score 8.6 vs 7.2
A free, open-source compiler for Java teams building browser applications or native targets.
- API access
- CLI access
8.6/10★★★★☆Visit TeaVM -
Best forJava teams building browser applications
- Better than js_of_ocaml:
- API access
- Editor score 8.5 vs 7.2
A Java-based route to browser applications, with compilation, widgets and testing tools.
- API access
- CLI access
8.5/10★★★★☆Visit GWT -
Best forClojure teams targeting browser and Node.js
- Better than js_of_ocaml:
- API access
- Editor score 8.4 vs 7.2
An open-source Clojure-to-JavaScript compiler with browser and Node.js targets.
- API access
- CLI access
8.4/10★★★★☆Visit ClojureScript -
Best forScala teams building JavaScript applications
- Better than js_of_ocaml:
- Intermediate output
- API access
- Editor score 8.3 vs 7.2
An open-source Scala-to-JavaScript toolchain with incremental builds and JavaScript interoperability.
- Intermediate output
- API access
- CLI access
8.3/10★★★★☆Visit Scala.js -
Best forTyped JavaScript teams wanting ReScript
- Better than js_of_ocaml:
- Editor score 8.2 vs 7.2
ReScript adds static typing to JavaScript projects and compiles to readable JavaScript.
- CLI access
8.2/10★★★★☆Visit ReScript -
Best forF# teams targeting several languages
- Better than js_of_ocaml:
- Editor score 8.1 vs 7.2
A self-hosted F# compiler with seven listed output targets and CLI workflows.
- CLI access
8.1/10★★★★☆Visit Fable -
Best forSmall teams removing types and JSX from JavaScript
- Better than js_of_ocaml:
- Editor score 8.0 vs 7.2
A free, focused transpiler for TypeScript, JSX and Flow in development workflows.
8.0/10★★★★☆Visit Sucrase -
Best forJava teams targeting TypeScript and JavaScript
- Better than js_of_ocaml:
- Syntax-version conversion
- Intermediate output
- Editor score 7.9 vs 7.2
An open-source Java-to-web transpiler for teams that want to keep Java syntax and tooling.
- Syntax-version conversion
- Intermediate output
- CLI access
7.9/10★★★★☆Visit JSweet -
Best forPython developers targeting browsers or Node.js
- Better than js_of_ocaml:
- Editor score 7.8 vs 7.2
A free, open-source Python-to-JavaScript compiler with CLI builds and debugging support.
- CLI access
7.8/10★★★★☆Visit Transcrypt -
Best forCoffeeScript users needing JavaScript output
- Better than js_of_ocaml:
- Syntax-version conversion
- Intermediate output
- API access
A concise alternative syntax for producing modern JavaScript, with CLI, REPL, and API access.
- Syntax-version conversion
- Intermediate output
- API access
7.7/10★★★★☆Visit CoffeeScript -
Best forRuby developers bringing code to JavaScript
- Better than js_of_ocaml:
- API access
- Editor score 7.6 vs 7.2
A free, open-source compiler for bringing Ruby code into JavaScript projects.
- API access
- CLI access
7.6/10★★★★☆Visit Opal
js_of_ocaml Alternatives: Common Questions
What is the best alternative to js_of_ocaml?
Babel: #1 in our Code Transpilers ranking, with an editor score of 9.3 out of 10. Flexible ECMAScript transforms with CLI, Node.js APIs, and browser compilation.
Is there a free alternative to js_of_ocaml?
Yes. Babel, SWC, Kotlin/JS, Cython and TeaVM have a free plan or a free tier (15 of the 15 alternatives on this page).
Why do people look for js_of_ocaml alternatives?
Requires compiling programs with OCaml bytecode tools first; Its scope is centered on OCaml-to-JavaScript workflows; Support channels are documentation and community.
Which js_of_ocaml alternative has the most source languages?
Fable, with 1 languages.
How do I switch from js_of_ocaml?
Export your data from js_of_ocaml (most tools have an export in their settings). Sign up for the alternative; start on its free plan or trial if it has one. Import your export and set up the integrations your team relies on. Run both side by side for a short while, then cancel js_of_ocaml.
How to Switch from js_of_ocaml
- Export your data from js_of_ocaml (most tools have an export in their settings).
- Sign up for the alternative; start on its free plan or trial if it has one.
- Import your export and set up the integrations your team relies on.
- Run both side by side for a short while, then cancel js_of_ocaml.
js_of_ocaml vs Each Alternative
| # | Tool | Free plan | Paid from | Intermediate output | API access | Score |
|---|---|---|---|---|---|---|
| 19 | js_of_ocaml | Free | No | No | 7.2 | |
| 1 | Babel | Yes | Free | Yes | Yes | 9.3 |
| 2 | SWC | Yes | Free | 9.2 | ||
| 3 | Kotlin/JS | Yes | Free | Yes | 8.8 | |
| 4 | Cython | Yes | Free | No | Yes | 8.7 |
| 5 | TeaVM | Yes | Free | Yes | 8.6 | |
| 6 | Google Web Toolkit | Yes | Free | Yes | 8.5 | |
| 7 | ClojureScript | Free | Yes | 8.4 | ||
| 8 | Scala.js | Free | Yes | Yes | 8.3 | |
| 9 | ReScript | Free | 8.2 | |||
| 10 | Fable | Free | 8.1 | |||
| 11 | Sucrase | Yes | Free | 8.0 | ||
| 12 | JSweet | Free | Yes | 7.9 | ||
| 13 | Transcrypt | Yes | Free | No | 7.8 | |
| 14 | CoffeeScript | Free | Yes | Yes | 7.7 | |
| 15 | Opal | Yes | Free | Yes | 7.6 |
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Last updated · How we research and update