Chapter 41: TypeScript Online Editor
TypeScript Online Editor — explained in detail like a patient human teacher
Imagine we are sitting together right now and I am showing you different websites on my screen while explaining why each one is useful (or not) in 2026.
There is not just one official TypeScript online editor — there are several very good ones, and each has slightly different strengths. The experience you get in 2026 is already extremely good compared to 5–6 years ago.
Here are the most important / most frequently used online TypeScript editors right now (February 2026), ordered roughly from most → least recommended for most people:
| Rank | Editor / Website | Best for | Biggest advantages in 2026 | Biggest disadvantages | Version control / share link | Dark mode | Mobile friendly |
|---|---|---|---|---|---|---|---|
| 1 | typescriptlang.org/play | Learning, quick experiments, asking for help | Always newest TypeScript version, official, perfect for teaching | No npm packages, no file system, no tests | Excellent (short links) | Yes | Okay |
| 2 | www.typescriptlang.org/play | Same as above + showing people bugs / ideas | Same as above | Same as above | Excellent | Yes | Okay |
| 3 | stackblitz.com (with TypeScript template) | Small real apps, React / Vite / Node demos | Full VS Code experience in browser, npm support | Slightly slower startup than playground | Very good | Yes | Poor |
| 4 | codesandbox.io (choose TypeScript / React) | Sharing React / Next.js / Vite mini-projects | Very polished UI, live preview, collaboration | Can feel heavy for tiny snippets | Very good | Yes | Poor |
| 5 | replit.com (new TS repl) | Learning in school, collaborative coding | Multiplayer editing, free forever tier | Less focused on TypeScript specifically | Good | Yes | Okay |
| 6 | jsfiddle.net (with TypeScript option) | Very quick “show this snippet” | Extremely lightweight | Very limited (no npm, weak TS support) | Okay | Yes | Good |
| 7 | onecompiler.com/typescript | Quick tests when you already have 10 tabs open | Simple, no login required | Weak editor, almost no TS features | Poor | No | Okay |
Most people in 2026 use these three in this order
- typescriptlang.org/play → 70–80% of learning / quick questions / bug reproduction
- StackBlitz → when they want to show a small working component / Vite app
- CodeSandbox → when they want a slightly nicer looking demo or live preview
Deep-dive: TypeScript Playground (typescriptlang.org/play)
This is the single most important TypeScript sandbox — every TypeScript teacher / documentation writer / conference speaker uses it.
What makes it special in 2026
- Always runs the very latest released TypeScript version (and beta/nightly too)
- You can switch between any released version back to ~3.0 (extremely useful when debugging “this worked in 4.9 but broke in 5.4” issues)
- Left = TypeScript, right = compiled JavaScript (you see exactly what is emitted)
- Very fast “share” button → creates short link like https://tsplay.dev/xxxxxx
- Built-in examples sidebar (very good for learning)
- Can change target (ES5 / ES2022 / ESNext), module (CommonJS / ESNext), strictness, lib array…
- Dark mode (automatic or manual)
- “TS config” button → almost full tsconfig experience
- Can import npm packages via CDN (not full npm, but many popular ones work: react, lodash, date-fns, zod…)
Quick live example you can copy-paste right now
Open https://www.typescriptlang.org/play
Paste this:
TypeScript
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type User = { id: number; name: string; email?: string; roles: ("admin" | "editor" | "viewer")[]; }; function greet(user: User): string { const role = user.roles[0] ?? "guest"; return `Hello ${user.name} ({role})`; } const sara = { id: 1, name: "Sara", roles: ["admin", "editor"] as const } satisfies User; console.log(greet(sara)); |
Now try these experiments:
- Remove satisfies User → see what happens to type of sara
- Change roles: [“admin”] → see literal type preserved
- Add wrong role → see nice error
- Switch TypeScript version to 4.8 → see satisfies disappear
- Click “TS config” → turn on exactOptionalPropertyTypes → see new errors
Quick comparison table (when to choose which)
| You want to… | Best choice | Why right now (2026) |
|---|---|---|
| Learn TypeScript basics / show a bug | typescriptlang.org/play | Official, fastest startup, newest TS version |
| Show small React / Vite component | StackBlitz | Full VS Code feel, instant preview, npm support |
| Make a polished mini-app / demo | CodeSandbox | Looks professional, collaboration, file tree |
| Collaborate with friend / student live | StackBlitz or Replit | Multiplayer editing works well |
| Just test one snippet super quickly | typescriptlang.org/play or jsfiddle | Zero login, zero loading |
Your first small exercise right now (takes 2–3 minutes)
- Go to https://www.typescriptlang.org/play
- Paste this broken code:
TypeScript
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const config = { apiUrl: "https://api.example.com", timeout: 5000, retry: true }; config.retry = "always"; // ← should be error |
- Fix it using as const + satisfies
- Click “Share” button → copy the link
- Paste the link here (optional) so I can see what you did
Which editor do you use most often right now? Or which one would you like to try together in more detail? 😄
