## List core web vital metrics trend

`speed.pages.trend(strurl, PageTrendParams**kwargs)  -> Trend`

**get** `/zones/{zone_id}/speed_api/pages/{url}/trend`

Lists the core web vital metrics trend over time for a specific page.

### Parameters

- `zone_id: str`

  Identifier.

- `url: str`

  A URL.

- `device_type: Literal["DESKTOP", "MOBILE"]`

  The type of device.

  - `"DESKTOP"`

  - `"MOBILE"`

- `metrics: str`

  A comma-separated list of metrics to include in the results.

- `region: Literal["asia-east1", "asia-northeast1", "asia-northeast2", 18 more]`

  A test region.

  - `"asia-east1"`

  - `"asia-northeast1"`

  - `"asia-northeast2"`

  - `"asia-south1"`

  - `"asia-southeast1"`

  - `"australia-southeast1"`

  - `"europe-north1"`

  - `"europe-southwest1"`

  - `"europe-west1"`

  - `"europe-west2"`

  - `"europe-west3"`

  - `"europe-west4"`

  - `"europe-west8"`

  - `"europe-west9"`

  - `"me-west1"`

  - `"southamerica-east1"`

  - `"us-central1"`

  - `"us-east1"`

  - `"us-east4"`

  - `"us-south1"`

  - `"us-west1"`

- `start: Union[str, datetime]`

- `tz: str`

  The timezone of the start and end timestamps.

- `end: Optional[Union[str, datetime]]`

### Returns

- `class Trend: …`

  - `cls: Optional[List[Optional[float]]]`

    Cumulative Layout Shift trend.

  - `fcp: Optional[List[Optional[float]]]`

    First Contentful Paint trend.

  - `lcp: Optional[List[Optional[float]]]`

    Largest Contentful Paint trend.

  - `performance_score: Optional[List[Optional[float]]]`

    The Lighthouse score trend.

  - `si: Optional[List[Optional[float]]]`

    Speed Index trend.

  - `tbt: Optional[List[Optional[float]]]`

    Total Blocking Time trend.

  - `ttfb: Optional[List[Optional[float]]]`

    Time To First Byte trend.

  - `tti: Optional[List[Optional[float]]]`

    Time To Interactive trend.

### Example

```python
import os
from datetime import datetime
from cloudflare import Cloudflare

client = Cloudflare(
    api_token=os.environ.get("CLOUDFLARE_API_TOKEN"),  # This is the default and can be omitted
)
trend = client.speed.pages.trend(
    url="example.com",
    zone_id="023e105f4ecef8ad9ca31a8372d0c353",
    device_type="DESKTOP",
    metrics="performanceScore,ttfb,fcp,si,lcp,tti,tbt,cls",
    region="us-central1",
    start=datetime.fromisoformat("2014-01-01T05:20:00.12345"),
    tz="tz",
)
print(trend.cls)
```

#### Response

```json
{
  "errors": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "messages": [
    {
      "code": 1000,
      "message": "message",
      "documentation_url": "documentation_url",
      "source": {
        "pointer": "pointer"
      }
    }
  ],
  "success": true,
  "result": {
    "cls": [
      0
    ],
    "fcp": [
      0
    ],
    "lcp": [
      0
    ],
    "performanceScore": [
      0
    ],
    "si": [
      0
    ],
    "tbt": [
      0
    ],
    "ttfb": [
      0
    ],
    "tti": [
      0
    ]
  }
}
```