Build a first radio-button group.

HTML: Learn how to build a first radio-button group in a complete browser example.

<!doctype html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Build a first radio-button group</title>
</head>
<body>
<label><input type="radio" name="size" value="s" checked>Small</label><label><input type="radio" name="size" value="l">Large</label>
</body>
</html>

Expected output EXAMPLE

Check the “Large” control.
The “Large” control is checked.
The “Small” control is not checked.

Details

Save as example.html and open in a modern browser. The output describes browser behavior verified with DOM and interaction assertions.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · 2026-11-02 18:13:31 UTC · Chromium 141.0.7390.37 · libc6 2.39-0ubuntu8.9; Playwright 1.56.0

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel: x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale: uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation: Chromium: open example.html; execute the published browser assertions
Container image ID: sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256: cdcaa3fe5a3cc3abd05cae7893cc2479a581cddbed182c9d25f77355cc8bae2e
Dependencies: libc6 2.39-0ubuntu8.9; Playwright 1.56.0

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Expected output describes the rendered page. The standard-output record below is the browser test harness receipt; the additional assertions check the result and interactions.

Build a first radio-button group: browser checks passed.

Exit code: 0. Standard error: empty. Validation: Shape/content assertions. System-dependent values above are one recorded run.

Additional assertions that passed

Checks recorded by the test harness. Where Python assertions are shown, browser cases use Playwright and simulator cases may inspect pin transitions: result.stdout is captured output, work is the temporary directory, and Path is pathlib.Path. The harness also imports json and csv.

await page.get_by_label('Large').check()
assert await page.get_by_label('Large').is_checked()
assert not await page.get_by_label('Small').is_checked()