Run 1 summary

https://example.com

Tested 2026-05-24 05:41:39 using Chrome 147.0.7727.137 (runtime settings)

SummaryWaterfall MetricsVideoFilmstrip CoachPageXrayThird partyScreenshots

Summary

LCP288 ms
CLS0.000
Coach99
Loading & responsiveness
TTFB
265 ms
First Paint
288 ms
Fully Loaded
307 ms
Page weight & requests
Total transfer size
807 B
Requests
2
Screenshot
| Waterfall | Download HAR | 

Waterfall

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Video

Run 1
Download video

Filmstrip

1 frame

Use --filmstrip.showAll to show all filmstrips.

0 sFirst Visual Change 0 msLast Visual Change 0 msVisual Complete 85% 0 msVisual Complete 95% 0 msVisual Complete 99% 0 ms
| Performance advice | Best practice advice | Privacy advice | Page info | Technologies | 

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

99
1 error1 warning
warn(90)Avoid extra requests by setting cache headerscacheHeaders

The page has 1 request that are missing a cache time. Configure a cache time so the browser doesn't need to download them every time. It will save 354 B the next access.

The easiest way to make your page fast is to avoid doing requests to the server. Setting a cache header on your server response will tell the browser that it doesn't need to download the asset again during the configured cache time! Always try to set a cache time if the content doesn't change for every request.

Offenders
error(90)Avoid missing and error requestsresponseOk

The page has 1 error response. The page has 1 response with code 404.

Your page should never request assets that return a 400 or 500 error. These requests are never cached. If that happens something is broken. Please fix it.

Offenders

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 2 responses 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

Page info

TitleExample Domain
Width1366
Height681
DOM elements11
Avg DOM depth3
Max DOM depth5
Iframes0
Script tags0
Local storage0 b
Session storage0 b
Network Information API4g

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
| Visual Metrics | Google Web Vitals | Largest Contentful Paint | Cumulative Layout Shift | Browser metrics | Long Aninimation Frames | Metrics from CDP | 

Visual Metrics

Visual progress
Visual progress at 0 s0.0s
FCP0.29s
LCP0.29s
0.0s0.0s0.0s0.1s0.1s0.1s

Google Web Vitals

Largest Contentful Paint

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

288 msLCP render time

Phase breakdown

  • TTFB265 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay23 ms

Element

Element type
<p>
Size (w × h)
28158
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

Want render-blocking and recalculate-style metrics for FCP and LCP, plus CPU long tasks? Run with --cpu.

Extra timings

Long Animation Frames

A long animation frame (LOAF) is a frame that took ≥ 50 ms from input to the next paint. The breakdown shows where that time went. Read more about the Long Animation Frames API.

Showing the top 10 longest animation frames.

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

CDP Performance33
AudioHandlers0
AudioWorkletProcessors0
Documents6
Frames7
JSEventListeners0
LayoutObjects23
MediaKeySessions0
MediaKeys0
Nodes40
Resources1
ContextLifecycleStateObservers13
V8PerContextDatas3
WorkerGlobalScopes0
UACSSResources0
RTCPeerConnections0
ResourceFetchers6
AdSubframes0
DetachedScriptStates2
ArrayBufferContents0
LayoutCount1
RecalcStyleCount2
LayoutDuration11
RecalcStyleDuration0
DevToolsCommandDuration5
ScriptDuration0
V8CompileDuration0
TaskDuration24
TaskOtherDuration8
ThreadTime0
ProcessTime0
JSHeapUsedSize1735776
JSHeapTotalSize2883584
FirstMeaningfulPaint287
| Summary | Largest responses | Per content type | Per domain | Expires & last-modified | After onLoad | 

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests2
Total domains1
Transfer size807 B
Content size1.0 KB
Missing compression0

Response codes

200
150.0%
404
150.0%

Largest assets on the page (by transfer size)

2 assets
URLTypeTransfer SizeContent Size
https://example.com/html453 B528 B
https://example.com/favicon.icohtml354 B528 B

Requests and sizes per content type

1 type
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b453 B528 B1
Total0 b453 B528 B1

Data per domain

1 domain
DomainTotal download timeTransfer SizeContent SizeRequests
example.com294 ms807 B1.0 KB2

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds0 seconds0 seconds
Last modified2 days2 days2 days

Requests loaded after onLoad event

1 request

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image0 b0
font0 b0
favicon0 b0
Total354 B1

Requests loaded after onContentLoad

1 request

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image0 b0
font0 b0
favicon0 b0
Total354 B1
| First vs third | 

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

2 requests

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

ContentHeader SizeTransfer SizeContent SizeRequests
html0 b453 B528 B1
css0 b0 b0 b0
javascript0 b0 b0 b0
image0 b0 b0 b0
font0 b0 b0 b0
favicon0 b0 b0 b0
TotalN/A807 B1.0 KB2

Third party requests and sizes per content type

requests
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b0 b0 b0
css0 b0 b0 b0
javascript0 b0 b0 b0
image0 b0 b0 b0
font0 b0 b0 b0
favicon0 b0 b0 b0
TotalN/AN/AN/A
| afterPageCompleteCheck.png | layoutShift.png | largestContentfulPaint.png | 

Screenshots