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/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/e... 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.
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.
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 time19 ms
Start2.7 s
RiskFOUT — text flashes from fallback to web font
lora-1ace0d36.woff2woff2swap
Size37 KB
Load time790 ms
Start2.7 s
RiskFOUT — text flashes from fallback to web font
lora-440ea47c.woff2woff2swap
Size40 KB
Load time791 ms
Start2.7 s
RiskFOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a...woff2swap
Size34 KB
Load time54 ms
Start5.4 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
No optimization needed
PASS
No optimization needed
Info::
✓
No resource hint issues
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.
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
✓
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
A
JavaScript Blocking
1 JS blocking issue(s) detected
PASS
1 JS blocking issue(s) detected
Warning::
!
Total JS execution time is 4.0 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.
A+
CSS Performance Depth
No CSS performance depth issues detected
PASS
No CSS performance depth issues detected
Info::
✓
No CSS performance depth issues detected
Asset Compression
No text asset hosts to measure
INFO
No text asset hosts to measure
Info::
i
No third-party or subdomain host served enough text assets to measure
Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.
Network Waterfall
88 requests over 6219ms
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-party3431ms · 267KB · NZ$51/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.gstatic.com
www.gstatic.com
Other
1337ms
0 KB
48%
NZ$20/mo
Costly
presentandperform.com
presentandperform.com
Other
943ms
21 KB
—
NZ$14/mo
Costly
presentandperform.com
presentandperform.com
Other
474ms
30 KB
—
NZ$7/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
360ms
175 KB
42%
NZ$5/mo
Costly
presentandperform.com
presentandperform.com
Other
140ms
0 KB
—
NZ$2/mo
Optional
presentandperform.com
presentandperform.com
Other
110ms
2 KB
—
NZ$2/mo
Optional
presentandperform.com
presentandperform.com
Other
66ms
39 KB
53%
NZ$1/mo
Optional
www.gstatic.com
Other
Costly
Execution1337ms
Transfer0 KB
Unused48%
Monthly CostNZ$20/mo
presentandperform.com
Other
Costly
Execution943ms
Transfer21 KB
Monthly CostNZ$14/mo
presentandperform.com
Other
Costly
Execution474ms
Transfer30 KB
Monthly CostNZ$7/mo
Google Tag Manager
Tag Manager
Costly
Execution360ms
Transfer175 KB
Unused42%
Monthly CostNZ$5/mo
presentandperform.com
Other
Optional
Execution140ms
Transfer0 KB
Monthly CostNZ$2/mo
presentandperform.com
Other
Optional
Execution110ms
Transfer2 KB
Monthly CostNZ$2/mo
presentandperform.com
Other
Optional
Execution66ms
Transfer39 KB
Unused53%
Monthly CostNZ$1/mo
These scripts may cost more than they're worth
www.gstatic.com adds 1337ms and costs ~NZ$20/month
presentandperform.com adds 943ms and costs ~NZ$14/month
presentandperform.com adds 474ms and costs ~NZ$7/month
Google Tag Manager adds 360ms and costs ~NZ$5/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 1337ms 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 943ms 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 474ms 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 360ms 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.