ReScript vs. Melange

rescript vs melange in 2026? which to choose and when?

Perplexity.ai answered (which was so good I decided to reshare it):

In 2026, Melange is the better fit if you want OCaml-first, dune/opam integration and sharing code with a backend; ReScript is better if you want a JS/TypeScript-team-friendly language that targets the JS ecosystem directly. github

How they differ

• Ecosystem focus:

  • Melange: Part of the OCaml world, installed via opam, built with dune, works with ocaml-lsp, ppxlib, etc., and compiles OCaml/Reason to JS. sancho
  • ReScript: JS-centric, distributed via npm as prebuilt binaries, positioned as an alternative to TypeScript with strong JS interop. discuss.ocaml

• Language and tooling:

  • Melange: Uses standard OCaml (or Reason) syntax, leverages OCaml’s type system and tooling; editor support comes “for free” via the OCaml LSP stack. discuss.ocaml
  • ReScript: Its own syntax and compiler, historically diverged from Reason/OCaml; has its own editor tooling and build story, more familiar to JS devs but less aligned with OCaml tooling. sancho

• Advanced features & evolution:

  • ReScript is adding features geared to JS devs like async/await syntax, new representation options, and improvements in JS interop, sometimes at the expense of OCaml compatibility. sancho
  • Melange maintains compatibility with OCaml versions and tooling, so it deliberately does not adopt features that would break that alignment. github

• Interop and code sharing:

  • Melange: Excellent if you want to share types and modules between OCaml backend and JS frontend (via dune, virtual libraries, etc.). discuss.ocaml
  • ReScript: Excellent if you primarily integrate with existing JS/React/Node codebases and care less about reusing OCaml libraries. discuss.ocaml

When to choose Melange

Pick Melange if:

• You already use OCaml on the backend and want a unified language and tooling front-to-back. discuss.ocaml
• You want dune, opam, ocaml-lsp, ppxlib, and the wider OCaml ecosystem to “just work.” discuss.ocaml
• You value readable, modular JS output and are comfortable with OCaml-style development rather than JS-style toolchains. github
• You may want to keep using Reason syntax or standard OCaml syntax with JSX via community dialects. dev

A concrete example: an OCaml-heavy company like Ahrefs moving their frontend to Melange to align frontend and backend while still using JS UI libraries. discuss.ocaml

When to choose ReScript

Pick ReScript if:

• Your team is primarily JavaScript/TypeScript developers, and you want something that feels like “better TypeScript” with strong static typing but JS-first ergonomics. reddit
• Your codebase and ecosystem are mostly JS/React, and you don’t need deep OCaml-library reuse or dune/opam integration. discuss.ocaml
• You are happy to follow ReScript’s language evolution, even when it diverges from OCaml (syntax and features). sancho

An example: a React SPA team that already lives in npm, Webpack/Vite, and JS tooling, adopting ReScript as a typed language close to their current stack. discuss.ocaml

Quick decision matrix

Situation	Choose	Why
OCaml backend, want shared types/libs with frontend	Melange	OCaml ecosystem integration, dune/opam, same language everywhere. github
Existing JS/React app, TS-style team	ReScript	JS-first tooling, npm distribution, TS-competitor positioning. sancho
Heavy use of OCaml ppx, advanced OCaml tooling	Melange	Full ppxlib and dune support, aligned with OCaml compiler. github
You don’t care about OCaml, just want a typed JS language	ReScript	Focus on JS interop and language features tailored to JS devs. sancho
Long-term bet on OCaml ecosystem (editor, libs, community)	Melange	Developed as an OCaml JS backend, maintained in OCaml community. github

If you tell me more about your current stack (OCaml vs JS, build tool, hosting, team background), I can map you to a very specific recommendation and migration path.