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

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.