Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
C
Image Optimization
Action
20 images, 0 KB saveable
REVIEW
20 images, 0 KB saveable
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/e... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/e... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://presentandperform.com/wp-content/uploads/2... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
20images911 KB
0oversized-0 KB
20legacy format
17missing dimensionsCLS risk
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
i
HTTP/3 (QUIC) is not advertised
HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.
C
Document Compression
Action
Document response served uncompressed
REVIEW
Document response served uncompressed
Info::
i
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
i
Main HTML response has no Cache-Control header
Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
i
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
B
JavaScript Blocking
2 JS blocking issue(s) detected
REVIEW
2 JS blocking issue(s) detected
Warning::
!
20 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
Warning::
!
Total JS execution time is 4.2 s -- over the 3.5s budget
Total JavaScript execution (parse + compile + run) across all scripts exceeds 3.5 seconds. On low-end devices that becomes 7-15+ seconds and shows up directly in TBT and INP. Reduce by: tree-shaking unused dependencies, code-splitting (dynamic `import()`), removing or deferring third-party tracking, and replacing heavy frameworks where they're not needed.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
✓
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
4 fonts (119 KB)
PASS
4 fonts (119 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
119 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
pxiByp8kv8JHgFVrLCz7Z1x...woff2swap
Size8 KB
Load time21 ms
Start2.9 s
RiskFOUT — text flashes from fallback to web font
lora-1ace0d36.woff2woff2swap
Size37 KB
Load time798 ms
Start2.9 s
RiskFOUT — text flashes from fallback to web font
lora-440ea47c.woff2woff2swap
Size40 KB
Load time802 ms
Start2.9 s
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time58 ms
Start5.9 s
RiskFOUT — text flashes from fallback to web font
Optimization checklist
Preload critical fonts (priority=high)
Use woff2 format for all fonts
Set font-display to swap, optional, or fallback
Subset large fonts (≤100 KB each)
A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
✓
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
✓
No render-blocking resources detected
A+
Resource Hints
4 hints, 0 missing preconnects
PASS
4 hints, 0 missing preconnects
Info::
✓
Page uses 4 resource hint(s)
Current Resource Hints
preconnect
1
preload
1
dns-prefetch
2
prefetch—
4 resource hints configured
A
Asset Compression
1 of 1 asset host still on gzip
PASS
1 of 1 asset host still on gzip
Info::
i
presentandperform.com serves assets with gzip; brotli would be ~20% smaller (assets: 117)
Every current browser accepts brotli. On a CDN this is a per-pull-zone toggle (Cloudflare, Fastly, CloudFront, CDN77, Bunny all expose it); on an origin it needs the brotli module (nginx-brotli, Apache mod_brotli). The saving lands on the assets this host serves, not on the HTML document -- the document's own encoding is reported separately.
Got: presentandperform.com (text/css)
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
✓
LCP image preload audit not available for this scan
A+
Server Response Intelligence
1 server-response signal(s) detected
PASS
1 server-response signal(s) detected
Info::
i
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
Each `<link rel="stylesheet">` without a non-blocking `media` attribute holds up the first paint. Browsers download all of them before painting any content. Consolidate into 1-2 critical-path stylesheets; defer non-critical CSS via `<link rel="stylesheet" media="print" onload="this.media='all'">` or via the loadCSS pattern; inline above-the-fold CSS in `<style>` to short-circuit the request entirely.
Network Waterfall
88 requests over 6635ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
86%of JavaScript execution is third-party
First-party Third-party3600ms · 267KB · NZ$34/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.gstatic.com
www.gstatic.com
Other
1249ms
0 KB
48%
NZ$12/mo
Costly
presentandperform.com
presentandperform.com
Other
1186ms
21 KB
—
NZ$11/mo
Costly
presentandperform.com
presentandperform.com
Other
473ms
30 KB
—
NZ$5/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
362ms
175 KB
42%
NZ$3/mo
Costly
presentandperform.com
presentandperform.com
Other
199ms
0 KB
—
NZ$2/mo
Optional
presentandperform.com
presentandperform.com
Other
70ms
39 KB
53%
NZ$1/mo
Optional
presentandperform.com
presentandperform.com
Other
61ms
2 KB
—
NZ$1/mo
Optional
www.gstatic.com
Other
Costly
Execution1249ms
Transfer0 KB
Unused48%
Monthly CostNZ$12/mo
presentandperform.com
Other
Costly
Execution1186ms
Transfer21 KB
Monthly CostNZ$11/mo
presentandperform.com
Other
Costly
Execution473ms
Transfer30 KB
Monthly CostNZ$5/mo
Google Tag Manager
Tag Manager
Costly
Execution362ms
Transfer175 KB
Unused42%
Monthly CostNZ$3/mo
presentandperform.com
Other
Optional
Execution199ms
Transfer0 KB
Monthly CostNZ$2/mo
presentandperform.com
Other
Optional
Execution70ms
Transfer39 KB
Unused53%
Monthly CostNZ$1/mo
presentandperform.com
Other
Optional
Execution61ms
Transfer2 KB
Monthly CostNZ$1/mo
These scripts may cost more than they're worth
www.gstatic.com adds 1249ms and costs ~NZ$12/month
presentandperform.com adds 1186ms and costs ~NZ$11/month
presentandperform.com adds 473ms and costs ~NZ$5/month
Google Tag Manager adds 362ms and costs ~NZ$3/month
86% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
Why this matters
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
www.gstatic.com takes 1249ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
presentandperform.com takes 1186ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
presentandperform.com takes 473ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Google Tag Manager takes 362ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
Why this matters
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
53% of presentandperform.com's code is unused. The script may be loading features you don't use.
Why this matters
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.