Measure page load time with PHP using Google PageSpeed Insights API

measurePageLoadTime.php

private static function getPageSpeedInsights($url) {
        $apiUrl = "https://www.googleapis.com/pagespeedonline/v5/runPagespeed";
        /*$queryParams = http_build_query([
            'url' => $url,
            'key' => 'YOUR_API_KEY' // If you plan on using the API in an automated way and making multiple queries per second, you'll need an API key
        ]);*/
        $queryParams = http_build_query([
            'url' => $url
        ]);

        $ch = curl_init("$apiUrl?$queryParams");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

        $response = curl_exec($ch);
        curl_close($ch);

        return json_decode($response, true);
    }

    private static function measurePageLoadTime() {
        echo "<h2>TEST measurePageLoadTime</h2>";
        $url = "url of website you want to measure";
        echo "Started measurePageLoadTime for $url...<br>";
        //Display the above message immediately, without waiting for operations to finish:
        ob_flush(); 
        flush();    
        $start_time = microtime(true);
        $result = self::getPageSpeedInsights($url);
        $end_time = microtime(true);
        if (isset($result['lighthouseResult']['audits']['first-contentful-paint']['displayValue'])) {
            $fcpValue = $result['lighthouseResult']['audits']['first-contentful-paint']['displayValue'];
            echo "First Contentful Paint: $fcpValue";
        } else {
            echo "First Contentful Paint data not available.";
        }
        echo "<br>Total time [s]: " . number_format($end_time - $start_time, 2) . "<br>";
    }