[[["わかりやすい","easyToUnderstand","thumb-up"],["問題の解決に役立った","solvedMyProblem","thumb-up"],["その他","otherUp","thumb-up"]],[["必要な情報がない","missingTheInformationINeed","thumb-down"],["複雑すぎる / 手順が多すぎる","tooComplicatedTooManySteps","thumb-down"],["最新ではない","outOfDate","thumb-down"],["翻訳に関する問題","translationIssue","thumb-down"],["サンプル / コードに問題がある","samplesCodeIssue","thumb-down"],["その他","otherDown","thumb-down"]],["最終更新日 2025-07-25 UTC。"],[[["\u003cp\u003eThis PageSpeed Insights API version (v4) is deprecated and will be shut down; please use the latest version (v5) for real-world and lab data.\u003c/p\u003e\n"],["\u003cp\u003ePageSpeed Insights (PSI) displays speed data from the Chrome User Experience Report, reflecting user experience over the past 30 days and updated daily.\u003c/p\u003e\n"],["\u003cp\u003eWhile PSI offers optimization suggestions, it's crucial to weigh implementation costs against the potential benefits for your specific website.\u003c/p\u003e\n"],["\u003cp\u003eIf speed data for a URL is unavailable in the CrUX dataset, consider using Lighthouse for a performance audit and optimization recommendations.\u003c/p\u003e\n"]]],["PageSpeed Insights (PSI) uses Chrome User Experience Report (CrUX) data, updated daily, to analyze a site's speed, either at the URL or origin level. PSI offers optimization suggestions based on web performance best practices and uses FCP and DCL metrics. PSI cautions that not all recommendations may be suitable for every site and suggests evaluating the cost versus benefit of implementing them. PSI uses a Blink renderer to fetch site data, showing captchas occasionally to ensure real user access, and it recommends CrUX data and Lighthouse for performance audits.\n"],null,["# Frequently Asked Questions\n\n| **Deprecated** . This page was written for version 4 of the PageSpeed Insights API, which is deprecated and will be shut down in May 2019. [Version 5](/speed/docs/insights/v5/get-started) is the latest and provides both real-world data from the Chrome User Experience Report and lab data from Lighthouse.\n\n1. [I changed my site! Why did the Speed or Optimization score not change?](#whyonlinestale)\n2. [Why am I not seeing any speed data for a URL?](#speedscoreunavailable)\n3. [What's the difference between origin-level speed data and url-level speed data?](#diffpageoriginspeed)\n4. [How does this differ from the Chrome User Experience Report?](#difftocrux)\n5. [Why does PSI use FCP and DCL? Which one is the most important?](#speedmetrics)\n6. [Where do the PageSpeed Insights performance optimizations come from?](#optimizationssource)\n7. [Should I implement all of the optimization recommendations?](#scoreandexperience)\n8. [Why am I seeing a captcha?](#captcha)\n\nI changed my site! Why did the Speed or Optimization score not change?\n: The speed data shown in PSI is not updated in real-time. The reported metrics reflect the user experience over the trailing thirty days and are updated on a daily basis. For the Optimization score, PageSpeed Insights caches results for a short period of time and any changes you've made to implement suggested optimizations should be recognized within a few minutes.\n\nWhy am I not seeing any speed data for a URL?\n: PSI uses data from the [Chrome User Experience Report](/web/tools/chrome-user-experience-report), which provides speed data for popular URLs that are known by Google's web crawlers. If the speed data for the queried URL is not available in the CrUX dataset, we recommend using Lighthouse to run a [synthetic performance audit](/web/tools/lighthouse) to estimate page speed, and investigate page optimization recommendations provided by PSI and Lighthouse.\n\nWhat's the difference between origin-level speed data and url-level speed data?\n: PSI uses the [Chrome User Experience Report](/web/tools/chrome-user-experience-report) to provide speed data about a single page or aggregated speed data about an origin. To query speed data for a single page, please provide the full URL of the page and PSI will show data about the speed of this page, e.g. \"http://www.example.com/about\". To query aggregated speed data for an origin, please provide the full URL of the origin with the \"origin:\" prefix and PSI will show data about the aggregated speed of all pages served from this origin, e.g. \"origin:http://www.example.com\". PSI only reports optimization information when analyzing a single page. [Learn more](/speed/docs/insights/about).\n\nHow does this differ from the Chrome User Experience Report?\n: PageSpeed Insights incorporates data from the [Chrome User Experience Report](/web/tools/chrome-user-experience-report) to provide real-world performance information for sites, as captured by FCP and DCL. The performance data in both CrUX and PSI is generated by real users in the wild and represents how users experience the web.\n\nWhy does PSI use FCP and DCL? Which one is the most important?\n: First Contentful Paint (FCP) measures when a user sees a visual response from the page. Faster times are more likely to [keep users engaged](/web/fundamentals/performance/rail). DOM Content Loaded (DCL) measures when HTML document has been loaded and parsed. Faster times have been shown to correlate with [lower bounce rates](https://www.thinkwithgoogle.com/marketing-resources/experience-design/mobile-page-speed-load-time/). We encourage you to look at a [variety of metrics](/web/updates/2017/06/user-centric-performance-metrics), including FCP and DCL to understand the performance of your page.\n\nWhere do the PageSpeed Insights performance optimizations come from?\n: PageSpeed Insights uses a variety of [best practices](/web/fundamentals/performance/critical-rendering-path) from the web performance community. The optimization analysis fetches a site with a Blink renderer (the rendering engine that powers Google Chrome) that emulates both mobile and desktop devices.\n\nShould I implement all of the optimization recommendations?\n: Since PageSpeed is a performance optimization tool, its recommendations are biased in favor of speed. However, we recognize that web development is complex, and our suggestions might be restrictive for an individual web site. You have to consider the tradeoffs for your own application: some of PageSpeed's recommendations take substantial effort to implement, so you need to evaluate the cost of making changes vs. the benefit the rule would have on your page. Our goal is simply to point out the issues that you should consider fixing.\n\nWhy am I seeing a captcha?\n: PageSpeed Insights may occasionally show a captcha to confirm you are not a bot. If you are encountering a captcha when using the API, it may be due to the fact that you are using a shared API key. You can acquire an individual API Key by following [these instructions](https://support.google.com/cloud/answer/6158862).\n\nFeedback\n--------\n\nWas this page helpful? \nYes Great! Thank you for the feedback. If you have a specific, answerable question about using PageSpeed Insights, ask the question in English on [Stack\n| Overflow](https://stackoverflow.com/questions/tagged/pagespeed-insights). For general questions, feedback, and discussion, start a thread in the [mailing list](https://groups.google.com/forum/#!forum/pagespeed-insights-discuss).\nNo Sorry to hear that. If you have a specific, answerable question about using PageSpeed Insights, ask the question in English on [Stack\n| Overflow](https://stackoverflow.com/questions/tagged/pagespeed-insights). For general questions, feedback, and discussion, start a thread in the [mailing list](https://groups.google.com/forum/#!forum/pagespeed-insights-discuss)."]]