## List core web vital metrics trend

`client.Speed.Pages.Trend(ctx, url, params) (*Trend, error)`

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

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

### Parameters

- `url string`

  A URL.

- `params PageTrendParams`

  - `ZoneID param.Field[string]`

    Path param: Identifier.

  - `DeviceType param.Field[PageTrendParamsDeviceType]`

    Query param: The type of device.

    - `const PageTrendParamsDeviceTypeDesktop PageTrendParamsDeviceType = "DESKTOP"`

    - `const PageTrendParamsDeviceTypeMobile PageTrendParamsDeviceType = "MOBILE"`

  - `Metrics param.Field[string]`

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

  - `Region param.Field[PageTrendParamsRegion]`

    Query param: A test region.

    - `const PageTrendParamsRegionAsiaEast1 PageTrendParamsRegion = "asia-east1"`

    - `const PageTrendParamsRegionAsiaNortheast1 PageTrendParamsRegion = "asia-northeast1"`

    - `const PageTrendParamsRegionAsiaNortheast2 PageTrendParamsRegion = "asia-northeast2"`

    - `const PageTrendParamsRegionAsiaSouth1 PageTrendParamsRegion = "asia-south1"`

    - `const PageTrendParamsRegionAsiaSoutheast1 PageTrendParamsRegion = "asia-southeast1"`

    - `const PageTrendParamsRegionAustraliaSoutheast1 PageTrendParamsRegion = "australia-southeast1"`

    - `const PageTrendParamsRegionEuropeNorth1 PageTrendParamsRegion = "europe-north1"`

    - `const PageTrendParamsRegionEuropeSouthwest1 PageTrendParamsRegion = "europe-southwest1"`

    - `const PageTrendParamsRegionEuropeWest1 PageTrendParamsRegion = "europe-west1"`

    - `const PageTrendParamsRegionEuropeWest2 PageTrendParamsRegion = "europe-west2"`

    - `const PageTrendParamsRegionEuropeWest3 PageTrendParamsRegion = "europe-west3"`

    - `const PageTrendParamsRegionEuropeWest4 PageTrendParamsRegion = "europe-west4"`

    - `const PageTrendParamsRegionEuropeWest8 PageTrendParamsRegion = "europe-west8"`

    - `const PageTrendParamsRegionEuropeWest9 PageTrendParamsRegion = "europe-west9"`

    - `const PageTrendParamsRegionMeWest1 PageTrendParamsRegion = "me-west1"`

    - `const PageTrendParamsRegionSouthamericaEast1 PageTrendParamsRegion = "southamerica-east1"`

    - `const PageTrendParamsRegionUsCentral1 PageTrendParamsRegion = "us-central1"`

    - `const PageTrendParamsRegionUsEast1 PageTrendParamsRegion = "us-east1"`

    - `const PageTrendParamsRegionUsEast4 PageTrendParamsRegion = "us-east4"`

    - `const PageTrendParamsRegionUsSouth1 PageTrendParamsRegion = "us-south1"`

    - `const PageTrendParamsRegionUsWest1 PageTrendParamsRegion = "us-west1"`

  - `Start param.Field[Time]`

    Query param

  - `Tz param.Field[string]`

    Query param: The timezone of the start and end timestamps.

  - `End param.Field[Time]`

    Query param

### Returns

- `type Trend struct{…}`

  - `CLS []float64`

    Cumulative Layout Shift trend.

  - `FCP []float64`

    First Contentful Paint trend.

  - `LCP []float64`

    Largest Contentful Paint trend.

  - `PerformanceScore []float64`

    The Lighthouse score trend.

  - `Si []float64`

    Speed Index trend.

  - `TBT []float64`

    Total Blocking Time trend.

  - `TTFB []float64`

    Time To First Byte trend.

  - `TTI []float64`

    Time To Interactive trend.

### Example

```go
package main

import (
  "context"
  "fmt"
  "time"

  "github.com/cloudflare/cloudflare-go"
  "github.com/cloudflare/cloudflare-go/option"
  "github.com/cloudflare/cloudflare-go/speed"
)

func main() {
  client := cloudflare.NewClient(
    option.WithAPIToken("Sn3lZJTBX6kkg7OdcBUAxOO963GEIyGQqnFTOFYY"),
  )
  trend, err := client.Speed.Pages.Trend(
    context.TODO(),
    "example.com",
    speed.PageTrendParams{
      ZoneID: cloudflare.F("023e105f4ecef8ad9ca31a8372d0c353"),
      DeviceType: cloudflare.F(speed.PageTrendParamsDeviceTypeDesktop),
      Metrics: cloudflare.F("performanceScore,ttfb,fcp,si,lcp,tti,tbt,cls"),
      Region: cloudflare.F(speed.PageTrendParamsRegionUsCentral1),
      Start: cloudflare.F(time.Now()),
      Tz: cloudflare.F("tz"),
    },
  )
  if err != nil {
    panic(err.Error())
  }
  fmt.Printf("%+v\n", 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
    ]
  }
}
```