Why this page exists: Vue 3
Here you can try Vue 3 in a constrained runner that favors clarity over project setup. The work area is meant for quick edits, quick failures, and quick confirmation when a language rule is fuzzy.
The Vue page runs a Vue 3 preview in the browser, so you can check component behavior without a build pipeline. The page returns output after the runner or preview finishes, which is usually only a few seconds for the kind of examples that belong here.
With the Composition API, refs need .value in script code, even though templates unwrap them for display. We would rather be blunt about that limit than make the page sound bigger than it is.
What it cannot prove
The runner is not a production environment. It will not carry durable state between serious sessions, and it should not be asked to handle router setup, Pinia-heavy state, SSR, build plugins, and package-version bugs. Good. Boundaries make bugs easier to see.
The sweet spot is template syntax, refs, computed values, event handlers, and small component examples. If your example needs a package manager, a database full of private rows, a web server listening on a port, or special build flags, move it to a local workspace before you draw conclusions.
A small runner should feel disposable. Try the idea, keep the useful lesson, and leave the accidental environment behind when the next step needs real project context.
Behind the scenes
- Start with the smallest Vue 3 snippet that can show the behavior.
- Add input only when the program reads it. Empty STDIN is a valid test case.
- Press Run, inspect stdout and stderr, then change one line. That rhythm keeps accidental fixes from hiding the real bug.
The page keeps the run path short. We keep the run cycle compact because this page is meant to answer one question at a time, not manage a full project tree.
That style also makes the result easier to share. A reader can scan a short Vue 3 snippet, run it, and see the same error without first recreating your directory structure or guessing which dependency you forgot to mention.
Concrete example
The editor itself is the example on this page. Change one visible value first, run or refresh the preview, and confirm that the output changed for the reason you expected.
Then test the part you actually care about. With the Composition API, refs need .value in script code, even though templates unwrap them for display. If the behavior still looks wrong in a tiny example, you have something worth investigating; if it only breaks in your app, the missing piece is probably project state, packages, or configuration.
Practical uses
Use it when you are stuck on someone else's machine, teaching a small concept, or separating a language question from a project question. No ceremony.
It also works well as a note-taking tool: paste the final snippet into your lesson, issue, or commit message after you have proved it in the runner.
Keep the example slightly smaller than feels natural. That sounds fussy, but it prevents a common debugging mistake: changing five pieces of code, getting a different result, and no longer knowing which piece mattered.
Questions from the editor
These answers focus on the runner's boundaries and the language details most likely to trip up a small Vue example.
What is the official Vue.js playground?
The official Vue playground is linked from the Vue documentation and is the safest place to check current framework behavior. This page is useful for quick Vue examples too, especially template syntax, refs, computed values, and events. For version-sensitive behavior, compare your snippet with the official Vue docs. A good browser-side test changes one prop, one state value, or one DOM element at a time.
Does Vue use a compiler?
Vue uses a compiler for templates. It turns template syntax into render functions that JavaScript can run. In a build setup, that often happens through tooling such as Vite. In a small online preview, the page handles the transform so you can focus on the component behavior. Check the console before rewriting the component; one earlier error can stop the update you expected.
What coding language does Vue use?
Vue apps are written mainly with HTML-like templates, JavaScript or TypeScript, and CSS. Single-file components usually put those pieces in template, script, and style blocks. The framework is JavaScript, but the authoring experience feels like a mix of markup, logic, and styles. A good browser-side test changes one prop, one state value, or one DOM element at a time. Check the console before rewriting the component; one earlier error can stop the update you expected.
Is vue.js still supported?
Vue is still actively used, with Vue 3 as the modern line. If you maintain an older Vue 2 app, check the official guidance before planning new work. For this page, focus on Vue 3-style examples such as refs, computed values, events, and simple component state. Check the console before rewriting the component; one earlier error can stop the update you expected.
How do I pass data between components?
For parent-to-child data, pass props. For child-to-parent communication, emit events. For example, a child can emit('save', value), and the parent can listen with @save. If many distant components need the same state, move to a store pattern rather than passing props through every level. A good browser-side test changes one prop, one state value, or one DOM element at a time.
Can I use the Composition API online?
Yes, small Composition API examples are a good fit online. Use ref for simple reactive values, computed for derived values, and watch when you need a side effect. Remember that refs use .value in script code, while Vue unwraps them for you in the template. Check the console before rewriting the component; one earlier error can stop the update you expected.
Can I run Vue Router or Vuex/Pinia online?
A tiny online Vue page is not the best place for router or store-heavy examples. You can explain the idea with a small mock object, but real Vue Router, Vuex, or Pinia behavior depends on project setup and installed packages. Use a local Vue project for that. A good browser-side test changes one prop, one state value, or one DOM element at a time.
Documentation
Reference pages are better than folklore when an error message gets specific. Start with official docs, then use tutorials for context once the rule is clear.