JavaScript / TypeScript
This is the default for most vibe coding, and for good reason. It runs everywhere — browsers, servers (Node.js), functions — and it's the language of the entire web . TypeScript is JavaScript with a type system bolted on, and you should almost always prefer TypeScript: the types catch mistakes early and, importantly, give the AI guardrails that make its output more reliable. A typed function signature is a contract the assistant can read; without it, the AI is guessing what shape your data takes, and guessing is where bugs hide.
- Good at: web apps (frontend and ), anything users click on in a browser, quick prototypes, full-stack projects in one language, /edge deployment.
- Where it hurts: the ecosystem moves fast and breaks things; sprawl is real (a tiny app can pull in hundreds of packages); plain JavaScript's looseness lets subtle bugs slip through — another reason to use TypeScript.
- Typical use cases: SaaS (Software as a Service — software you rent online instead of installing) dashboards, landing pages, e-commerce, real-time apps, browser extensions, anything you to Vercel, Netlify, or Cloudflare.
- AI handling: excellent. This is the most-represented language in training data. Assistants write React, Next.js, and Node confidently and rarely get stuck. If you have no strong reason to choose otherwise, start here.
One concrete trade-off worth knowing: the speed that makes JavaScript great for prototyping is the same speed that makes it churn. A tutorial from eighteen months ago may already use a deprecated , and the AI — trained on a snapshot of the past — will sometimes hand you yesterday's pattern. When something it writes doesn't work, the cause is often that the library moved on. The fix is usually to tell it the version you're on and ask it to check current docs. This is a tax you pay for living in the most active ecosystem on earth, and for most projects it's worth paying.