> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stably.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Capabilities

> Understand what the Stably Web Editor supports and its limitations

The Stably Web Editor supports most capabilities that Playwright provides, with a few limitations.

## Playwright Compatibility

Since Stably tests are built on top of [Playwright](https://playwright.dev/), you get access to the full range of Playwright's powerful testing capabilities:

* **Selectors**: CSS selectors, text selectors, XPath, and more
* **Actions**: Click, fill, hover, drag-and-drop, keyboard input, and other interactions
* **Assertions**: Visibility checks, text content, element state, and custom assertions
* **Navigation**: Page navigation, URL handling, and browser history
* **Network**: Request interception, mocking, and API testing
* **Screenshots & Video**: Visual captures and recordings for debugging
* **File Handling**: Upload and download support

For the complete list of Playwright capabilities, see the [Playwright documentation](https://playwright.dev/docs/intro).

## AI-Enhanced Features

In addition to standard Playwright capabilities, Stably adds AI-powered features:

* **[AI Assertions](/stably-sdk/ai-assertions)**: Use natural language to verify visual and functional states
* **[AI Locator](/stably-sdk/ai-locator)**: Self-healing locators that adapt to UI changes
* **[AI Extraction](/stably-sdk/ai-extraction)**: Extract data from pages using natural language
* **[AI Agent Execute](/stably-sdk/ai-agent-execute)**: Perform complex multi-step actions with AI

## Browser Support

<Note>
  The **Stably Web Editor** only supports **Chromium** browsers.

  If you need to run tests on **Firefox** or **WebKit**, use the [Stably CLI](/stably-cli/quickstart) with the `stably test` command, which supports all three browser engines.
</Note>

| Browser  | Web Editor | CLI (`stably test`) |
| -------- | ---------- | ------------------- |
| Chromium | Yes        | Yes                 |
| Firefox  | No         | Yes                 |
| WebKit   | No         | Yes                 |

## Limitations

While Stably supports most Playwright features, there are a few limitations to be aware of:

* **Browser engines**: Web editor is limited to Chromium (use CLI for Firefox/WebKit)
* **Some advanced Playwright APIs**: Certain low-level APIs may not be available in the visual editor, but can be used via [custom code steps](/platform-capabilities/custom-code)

## Next Steps

<CardGroup cols={2}>
  <Card title="Web Editor Quickstart" icon="play" href="/stably2/web-quickstart">
    Get started with the Stably Web Editor
  </Card>

  <Card title="CLI Quickstart" icon="terminal" href="/stably-cli/quickstart">
    Run tests locally with full browser support
  </Card>
</CardGroup>