Page summary

https://www.example.com

Tested 2026-08-17 06:54:02 using Chrome 151.0.7922.75 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPUThird party

This page is fast to paint, snappy to interact with and visually stable, but loose on best practices and weak on user privacy.

87 / 100
Coach overall
100 / 100
Performance
88 / 100
Best practice
69 / 100
Privacy

How it loaded →

0 → 33 ms · median run
Frame at 0 ms
start
Frame at 100 ms
Complete100 ms
33 ms
First Visual Change
33 ms
Speed Index
33 ms
Visual Complete 85%
33 ms
Last Visual Change
TTFB24 msLCP44 msTBT0 msCLS0.00

Nothing to act on

You're in good shape

Coach found no failing performance checks and every Core Web Vital is in the good range. Keep an eye on the trend: regressions show up here first.

Google Web Vitals

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Time To First Byte (TTFB)24 ms24 ms24 ms24 ms
Largest Contentful Paint (LCP)44 ms44 ms44 ms44 ms
Cumulative Layout Shift (CLS)0000

Visual Metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First visual change33 ms33 ms33 ms33 ms
Last visual change33 ms33 ms33 ms33 ms
Speed index33 ms33 ms33 ms33 ms
Visual readiness0 ms0 ms0 ms0 ms
Visual complete 8533 ms33 ms33 ms33 ms
Visual complete 9533 ms33 ms33 ms33 ms
Visual complete 9933 ms33 ms33 ms33 ms

CPU

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Total Blocking Time0 ms0 ms0 ms0 ms
Max Potential FID0 ms0 ms0 ms0 ms
CPU long tasks 0000
CPU last long task happens at0 ms0 ms0 ms0 ms

More metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First paint44 ms44 ms44 ms44 ms
Load event end31 ms31 ms31 ms31 ms

Waterfall

Run 1 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1 · median
0.000 s
0s
Download video

Filmstrip

2 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 100 ms
100 ms
100 %

Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 44 ms on a 24 ms first byte.

Want to see how much CSS style-recalculation work delayed FCP and LCP, plus CPU long tasks? Run with --cpu.

Coach

The coach helps you find performance problems on your web page using web performance best practice rules. And gives you advice on privacy and best practices. Tested using Coach-core version 9.2.1.

Performance advice

100

✓ You have a perfect Performance score!

Best practice advice

88
3 info
infoMeta descriptionmetaDescription

The page is missing a meta description.

Use a page description to make the page more relevant to search engines.

infoDeclare a charset in your documentcharset

You are not using charset UTF-8?

The Unicode Standard (UTF-8) covers (almost) all the characters, punctuations, and symbols in the world. Please use that.

infoAvoid unnecessary headersunnecessaryHeaders

There are 1 response that sets a server header.

Do not send headers that you don't need. We look for p3p, cache-control and max-age, pragma, server and x-frame-options headers. Have a look at Andrew Betts - Headers for Hackers talk as a guide https://www.youtube.com/watch?v=k92ZbrY815c or read https://www.fastly.com/blog/headers-we-dont-want.

Offenders

Privacy advice

69
1 error6 warnings4 info
warn(0)Declare a referrer policy on the documentreferrerPolicy

No <meta name="referrer"> tag was found on the page. Set a Referrer-Policy response header (preferred) or add a meta tag, for example <meta name="referrer" content="strict-origin-when-cross-origin">.

Without an explicit referrer policy the browser falls back to the user-agent default and may leak the full URL of the previous page (including query strings) to every cross-origin request. Set a Referrer-Policy response header (preferred) or a <meta name="referrer"> tag in the document. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy

warn(0)Use a strict Content-Security-Policy header to mitigate cross-site scripting (XSS) attacks.contentSecurityPolicyHeader

Set a Content-Security-Policy header to mitigate cross-site scripting attacks. You can start with a Content-Security-Policy-Report-Only header, which only reports violations rather than blocking them.

A Content-Security-Policy response header tells the browser which sources of script, style, and other content are allowed. The most effective form is a strict CSP using nonces or hashes together with strict-dynamic; the worst is a missing header, with unsafe-inline and unsafe-eval close behind. https://web.dev/articles/strict-csp

Offenders
infoSet a Cross-Origin-Embedder-Policy header so cross-origin subresources opt in to being embedded.crossOriginEmbedderPolicyHeader

Set a Cross-Origin-Embedder-Policy header (typically require-corp or credentialless) on the document response to control cross-origin embedding.

Cross-Origin-Embedder-Policy (COEP) makes the page refuse to load cross-origin subresources unless they explicitly opt in via CORP or CORS. Together with Cross-Origin-Opener-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Embedder-Policy

Offenders
warn(0)Set a Cross-Origin-Opener-Policy header to isolate the page from cross-origin windows.crossOriginOpenerPolicyHeader

Set a Cross-Origin-Opener-Policy header (typically same-origin) on the document response to isolate the page from cross-origin windows.

Cross-Origin-Opener-Policy (COOP) lets a page sever its window-group ties to cross-origin documents that opened it or that it opens. Together with Cross-Origin-Embedder-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Opener-Policy

Offenders
infoSet a Cross-Origin-Resource-Policy header to limit who may embed the page.crossOriginResourcePolicyHeader

Set a Cross-Origin-Resource-Policy header (same-origin, same-site or cross-origin) on the document response to limit who may embed it.

Cross-Origin-Resource-Policy (CORP) is a per-response opt-in that tells the browser which origins are allowed to embed the resource. It blocks cross-origin or cross-site no-cors embedding (img, script, iframe, etc.) and is one of the building blocks of cross-origin isolation. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Resource-Policy

Offenders
infoSet a NEL header so the browser reports network errors back to you.nelHeader

Set a NEL header (paired with Reporting-Endpoints) to collect connection-level error reports from the field.

The NEL (Network Error Logging) response header tells the browser to record connection-level failures (DNS, TLS, HTTP errors) and ship them to a reporting endpoint. NEL pairs with the Reporting-Endpoints / Report-To header — the page declares the endpoint group and NEL points at it. Together they give you visibility into errors that never reach your origin server. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/NEL

Offenders
warn(0)Set a Permissions-Policy header to control which browser features the page can use.permissionsPolicyHeader

Set a Permissions-Policy header to control which browser features the page can use.

The Permissions-Policy response header (the successor to Feature-Policy) lets a site explicitly opt in or out of powerful browser features such as camera, microphone, geolocation, payment and clipboard. Setting a strict policy reduces the attack surface and limits what embedded third parties can do. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Permissions-Policy

Offenders
warn(0)Set a referrer-policy header to make sure you do not leak user information.referrerPolicyHeader

Set a referrer-policy header to make sure you do not leak user information.

Referrer Policy is a new header that allows a site to control how much information the browser includes with navigations away from a document and should be set by all sites. https://scotthelme.co.uk/a-new-security-header-referrer-policy/.

Offenders
infoDeclare reporting endpoints so the browser can deliver Reporting-API events.reportingEndpointsHeader

Set a Reporting-Endpoints header (or the legacy Report-To header) so CSP reports, NEL data and other Reporting-API events have an endpoint to land at.

The Reporting-Endpoints response header (the successor to Report-To) names the URLs that browsers should POST reports to. Without it, CSP report-to directives, Cross-Origin-Opener-Policy reports, NEL data and other Reporting-API events have nowhere to go. The legacy Report-To header is still accepted for older Chromium versions. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Reporting-Endpoints

Offenders
error(0)Set a strict transport header to make sure the user always use HTTPS.strictTransportSecurityHeader

Set a strict transport header to make sure the user always use HTTPS.

The HTTP Strict-Transport-Security response header (often abbreviated as HSTS) lets a web site tell browsers that it should only be accessed using HTTPS, instead of using HTTP. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Strict-Transport-Security.

Offenders
warn(0)Set X-Content-Type-Options: nosniff to stop the browser from MIME-sniffing the response.xContentTypeOptionsHeader

Set X-Content-Type-Options: nosniff on the document response to prevent MIME-sniffing.

X-Content-Type-Options: nosniff prevents browsers from interpreting files as a different MIME type than what is declared in the Content-Type header. This blocks a class of cross-site scripting and content-type confusion attacks and should be set on every response. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options

Offenders

Page info

A snapshot of what the browser actually built for this page: the document, how big and deep the DOM tree is and what it kept in storage. Big, deep trees are slower to style and lay out, so the counts Chrome warns about carry a flag.

Page info

Document

What the page says it is and how large it rendered.

TitleExample DomainThe document title, shown in the browser tab and used by search results.
Layout viewport1365 × 620 pxThe width the page laid out at, and the full height of the rendered document.

DOM structure

How much markup the browser has to build, style and lay out.

DOM elements12Total HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth3How deeply elements are nested on average.
Max DOM depth5The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes0No embedded documents on this page.
Script tags0Number of script elements. More scripts usually means more main-thread work.

Storage and connection

What the page stored on the client, and the network it was tested on.

Local storage0 bData the page saved in localStorage, kept across visits.
Session storage0 bData kept in sessionStorage for this tab session only.
Connection type4GWhat the Network Information API reported for the test connection.

Technologies used to build the page

Data collected using Coach-core version 9.2.1. With updated code from Webappanalyzer 2026-05-04. Use --browsertime.firefox.includeResponseBodies html or --browsertime.chrome.includeResponseBodies html to help Wappalyzer find more information about technologies used.

Detected technologies

1 technology

Data from run 1

Visual Metrics

Visual milestones

all times from navigation start
Speed Index0.03 show quickly the page looked done
First Visual Change0.03 sfirst paint reaches the screen
Last Visual Change0.03 sscreen stops changing
nothing painted yet
First Visual Change · Visual Complete 85% · Visual Complete 95% · Visual Complete 99% · Last Visual Change0.03 s
0
Content milestones
Perception index
Visual progress
Visual progress at 0 s0.0s
Visual progress at 0.1 s0.1s
FCP0.04s
LCP0.04s
VC850.03s
0.0s0.0s0.0s0.1s0.1s0.1s

Google Web Vitals

from run 1

Largest Contentful Paint

When the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.

44 msLCP render time

Phase breakdown

  • TTFB24 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay20 ms

Element

Element type
<p>
Size (w × h)
28120
Load time
0 ms

DOM path

body > div > p:eq(0)
LCP

The LCP element is highlighted in the screenshot. If nothing is highlighted the element was removed before the screenshot or the LCP API couldn't find it.

Cumulative Layout Shift

How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.

0.000cumulative layout shift score

No layout shifts were detected on this page.

Browser Metrics

Navigation Timing
Extra timings

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests1
Total domains1
Transfer size474 B
Content size559 B
Missing compression0

Main document

status 200 · 0 redirects

https://www.example.com/

HeaderValue
age11301
allowGET, HEAD
cf-cache-statusHIT
cf-raya2c6c3e63c50de03-SJC
content-encodingbr
content-typetext/html
dateMon, 17 Aug 2026 06:54:03 GMT
last-modifiedWed, 12 Aug 2026 20:15:57 GMT
servercloudflare

Response codes

200
1100.0%

Largest assets on the page (by transfer size)

1 asset
URLTypeTransfer SizeContent Size
https://www.example.com/html474 B559 B

Requests and sizes per content type

1 type

Transfer size474 B

  • html100.0%

Content size559 B

  • html100.0%

Requests1

  • html100.0%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b474 B559 B1
Total0 b474 B559 B1

Data per domain

1 domain
DomainTotal download timeTransfer SizeContent SizeRequests
www.example.com28 ms474 B559 B1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds0 seconds0 seconds
Last modified4 days4 days4 days

CPU

Get deeper CPU insight with one extra run
Run with --enableProfileRun to see where main-thread time went, blocking time and CPU cost per script, module and function, forced reflows and frame stability. The data is collected in one extra run, so the timing metrics of your measured runs stay untouched.

Long tasks

Tasks ≥ 50 ms blocking the main thread, collected via the Long Task API.

✓ No long tasks observed during this run.

Third party

Third party requests categorised by Third party web version 0.29.2.

No third-party requests detected

Every request on this page resolved to a first-party domain. There are no entries in Third party web to attribute, no third-party tools to enumerate, and no third-party cookies set. If you expected to see entries here you can fine-tune the first-party domain list with --firstParty.

First party requests and sizes per content type

1 request

Calculated using .*example.* (use --firstParty to configure).

ContentHeader SizeTransfer SizeContent SizeRequests
html0 b474 B559 B1
css0 b0 b0 b0
javascript0 b0 b0 b0
image0 b0 b0 b0
font0 b0 b0 b0
favicon0 b0 b0 b0
TotalN/A474 B559 B1