About this runner: AngularJS
AngularJS is easiest to reason about when the experiment is small. Put the code in the code panel, add input only if the snippet reads input, and run it once before you start editing around the problem.
The AngularJS page runs the sample in the client-side preview, so the digest cycle happens in this tab rather than on a remote server. We chose that setup so the page can answer quick syntax and behavior questions without pretending to be your whole development machine.
AngularJS 1.x is built around scopes and dirty checking; forgetting a digest boundary is a classic reason a model changes but the screen does not. Tiny repros are honest. They either show the issue, or they tell you the issue lives somewhere else.
Known gaps
The runner is not a production environment. It will not carry durable state between serious sessions, and it should not be asked to handle new production projects, modern Angular examples, and anything that depends on a build step. Good. Boundaries make bugs easier to see.
The sweet spot is checking old directives, filters, scope expressions, and migration notes before touching a legacy codebase. 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.
The run path
- Start with the smallest AngularJS 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 AngularJS snippet, run it, and see the same error without first recreating your directory structure or guessing which dependency you forgot to mention.
A worked check
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. AngularJS 1.x is built around scopes and dirty checking; forgetting a digest boundary is a classic reason a model changes but the screen does not. 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.
Good 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.
FAQ
Only a few questions belong here. The goal is to answer the mistakes that actually interrupt a small AngularJS run, not to pad the page.
How does scope and two-way data binding work in AngularJS 1.x?
In AngularJS 1.x, scope is the object that connects the controller and the template. Two-way binding means a change in the input can update the model, and a model change can update the view during the digest cycle. If a value does not refresh, check whether AngularJS knows the change happened. A good browser-side test changes one prop, one state value, or one DOM element at a time.
What are controllers and how do they fit with the view in AngularJS 1.x?
A controller in AngularJS 1.x prepares data and functions for the view. The template reads those values through scope, then directives such as ng-click call controller methods. Keep controllers small. If a controller starts fetching data, formatting dates, and handling UI state, split that work into services or components. Check the console before rewriting the component; one earlier error can stop the update you expected.
What are the most common AngularJS 1.x directives I should know?
The AngularJS directives you will see most often are ng-app, ng-controller, ng-model, ng-repeat, ng-if, ng-show, and ng-click. They attach AngularJS behavior to normal HTML. A good first test is ng-repeat over a three-item array; if that works, add filtering or click handlers one piece at a time. A good browser-side test changes one prop, one state value, or one DOM element at a time.
How do filters work in AngularJS 1.x?
Filters format values before they appear in the template. Common examples include currency, date, uppercase, lowercase, orderBy, and filter. They are handy for display, but avoid putting heavy business logic in them. If the formatting grows complicated, move that logic into the controller or a small helper service. Check the console before rewriting the component; one earlier error can stop the update you expected.
How to run Angular code online?
Put your HTML in the template pane, controller code in the JS pane, and any styles in the CSS pane. The page loads AngularJS 1.8 and renders your view live on the right. Press Run to refresh after edits.
Is this Angular playground free to use?
Yes, it's free and doesn't require any login. AngularJS 1.8 is preloaded, so you can test directives, two-way bindings, and controllers without installing anything.
Can I use this for Angular programming practice?
Yes - directives, $scope, ng-model, ng-repeat, and controllers all work for quick practice. For complex multi-file apps with services and routing, install AngularJS in a real project.
Docs worth opening
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.