SuperJS vs TypeScript — one pager

For press / launch. Full comparison: docs/comparisons/sjs-vs-typescript.md.

One sentence

SuperJS is JavaScript with a sound type system — it removes TypeScript's unsound escape hatches instead of adding more configuration.

When to choose SuperJS

• You want provable null safety without strictNullChecks footguns
• You're tired of any silently infecting call chains
• You want sum types + exhaustive match without discriminated-union ceremony
• You need a smaller language that's easier to teach and review

When to stay on TypeScript

• You depend heavily on mapped/conditional types and library inference
• Your team needs the full npm @types/* ecosystem without wrappers
• You require a mature IDE/debugger story today (SJS DAP is post-1.0)

Feature contrast

Benchmark snapshot

Synthetic ~14k LOC corpus (macOS arm64, Node 24):

See docs/perf/.

Try it

npm install -g @superjsorg/cli
superjs init
superjs build

Playground: https://superjs.org/playground