# Check Server Response Time (TTFB) for Any URL

**Use case:** 

Measure how fast a server responds — TTFB plus full Core Web Vitals context for one URL or a whole list.

## Input

```json
{
  "urls": [
    "https://apify.com"
  ],
  "device": "desktop",
  "waitUntil": "load",
  "timeoutMs": 60000,
  "proxyConfiguration": {
    "useApifyProxy": false
  }
}
```

## Output

```json
{
  "url": {
    "label": "URL",
    "format": "text"
  },
  "score": {
    "label": "Score",
    "format": "number"
  },
  "lcpMs": {
    "label": "LCP ms",
    "format": "number"
  },
  "cls": {
    "label": "CLS",
    "format": "number"
  },
  "fcpMs": {
    "label": "FCP ms",
    "format": "number"
  },
  "ttfbMs": {
    "label": "TTFB ms",
    "format": "number"
  },
  "totalKb": {
    "label": "Weight KB",
    "format": "number"
  },
  "requests": {
    "label": "Requests",
    "format": "number"
  },
  "opportunityCount": {
    "label": "Issues",
    "format": "number"
  }
}
```

## About this Actor

This example demonstrates how to use [Bulk Lighthouse & Core Web Vitals Audit — Page Speed](https://apify.com/fetchbase/website-performance-audit) with a specific input configuration. Visit the [Actor detail page](https://apify.com/fetchbase/website-performance-audit) to learn more, explore other use cases, and run it yourself.