# Screen test

- Human page: https://happytails.ai/en/device-tools/screen-test/
- Markdown: https://happytails.ai/en/device-tools/screen-test.md
- Structured JSON: https://happytails.ai/agents/en/device-tools/screen-test/index.json
- Visibility: public

## Tool capabilities

| Property | Value |
| --- | --- |
| Tool ID | `screen-test` |
| Category | device-tools |
| Implementation | Registered implementation. Registration alone is not a production-quality guarantee. |
| Browser execution | Use the visible action or interactive controls. |
| Browser processing | Browser; see tool notes for network behavior. |
| HTTP API | Not callable through HTTP. |
| Browser-agent interface | No callable WebMCP interface. |

### Implementation notes

Choose a color and inspect your display. This is a visual inspection, not automatic hardware diagnosis.

### Inputs and settings

No free-text input is required. Use the file inputs and/or settings below.

No additional settings are declared for this tool.

### Planning specification

Fullscreen solid colors, keyboard exit and display instructions; no guaranteed diagnosis.

This describes intended requirements. Use the implementation notes, interface schema and observed output to determine current support.

### Complete machine-readable capability record

```json
{
  "id": "screen-test",
  "category": "device-tools",
  "built": true,
  "requirements": "Fullscreen solid colors, keyboard exit and display instructions; no guaranteed diagnosis.",
  "implementation": {
    "fields": [],
    "input": false,
    "note": "Choose a color and inspect your display. This is a visual inspection, not automatic hardware diagnosis.",
    "experience": {
      "automatic": false,
      "single": false,
      "label": "Your text",
      "placeholder": "Type or paste your input…",
      "help": "Up to 1,000,000 characters. Review the settings before running.",
      "action": null
    },
    "mode": "explicit",
    "interactive": true
  },
  "execution": "Browser interface",
  "api": null,
  "browser_agent": {
    "supported": false,
    "name": null,
    "discovery": "WebMCP on the human page in a supporting browser",
    "verification": "See audit/API-AUDIT.md; availability is not verification"
  }
}
```

## Page guide

Inspect your screen using solid colors.

## Useful next steps

- [Webcam test](https://happytails.ai/en/device-tools/webcam-test/): Preview your webcam in the browser. ([Markdown](https://happytails.ai/en/device-tools/webcam-test.md))

- [Microphone test](https://happytails.ai/en/device-tools/microphone-test/): Check the input level from your microphone. ([Markdown](https://happytails.ai/en/device-tools/microphone-test.md))

- [Keyboard test](https://happytails.ai/en/device-tools/keyboard-test/): Check which key and modifier signals your browser receives. ([Markdown](https://happytails.ai/en/device-tools/keyboard-test.md))

## How to use Screen test

1. Choose a test color.
2. Inspect the colored area, or choose Full screen for a larger view.
3. Try the other colors. Press Escape to leave full-screen mode.

## What to expect

Inspect your screen using solid colors. Look for pixels that stay a different color as you switch backgrounds. This is a visual inspection, not an automatic hardware diagnosis.