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
16 images, 0 KB saveable
REVIEW
16 images, 0 KB saveable
Warning::
!
https://www.agu.org/-/media/AGU4You/Header-and-Par... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/Feature/Common/Agu/Ima... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/Feature/Common/Agu/Ima... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/Feature/Common/Agu/Ima... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/AGU4You/Header-and-Par... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/AGU4You/Header-Module/... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/AGU4You/Header-and-Par... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.agu.org/-/media/AGU4You/Header-and-Par... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
16images3.7 MB
0oversized-0 KB
8legacy format
8missing 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
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
9 fonts (1468 KB)
PASS
9 fonts (1468 KB)
Info::
i
9 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
9
1468 KB total
Render-blocking
0
of 9
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
fa-regular-400.woff2woff2swap
Size416 KB
Load time41 ms
Start3.2 s
RiskFOUT — text flashes from fallback to web font
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
fa-brands-400.woff2woff2swap
Size117 KB
Load time30 ms
Start3.2 s
RiskFOUT — text flashes from fallback to web font
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
fa-light-300.woff2woff2swap
Size455 KB
Load time42 ms
Start3.2 s
RiskFOUT — text flashes from fallback to web font
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
DMSans-Medium.woffwoffswap
Size32 KB
Load time43 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
DMSans-Regular.woffwoffswap
Size32 KB
Load time41 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
fa-solid-900.woff2woff2swap
Size346 KB
Load time45 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
lora-v23-latin-500.woff2woff2swap
Size19 KB
Load time32 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
lora-v23-latin-regular....woff2swap
Size19 KB
Load time36 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
DMSans-Bold.woffwoffswap
Size32 KB
Load time42 ms
Start3.3 s
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
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)
Fixing the unchecked items could save ~696 KB and ~1392 ms
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+
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+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall
108 requests over 4593ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100%of JavaScript execution is third-party
First-party Third-party6285ms · 7470KB · $83/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.agu.org
www.agu.org
Other
1396ms
4413 KB
—
$19/mo
Costly
www.agu.org
www.agu.org
Other
777ms
58 KB
—
$10/mo
Costly
Unattributable
Unattributable
Other
685ms
0 KB
—
$9/mo
Costly
www.agu.org
www.agu.org
Other
570ms
707 KB
—
$8/mo
Costly
www.agu.org
www.agu.org
Other
432ms
624 KB
—
$6/mo
Costly
www.agu.org
www.agu.org
Other
422ms
467 KB
—
$6/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
403ms
177 KB
34%
$5/mo
Costly
www.agu.org
www.agu.org
Other
260ms
143 KB
76%
$3/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
172ms
149 KB
55%
$2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
170ms
137 KB
47%
$2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
143ms
137 KB
51%
$2/mo
Optional
Hotjar
script.hotjar.com
Session Replay
137ms
57 KB
65%
$2/mo
Optional
js-agent.newrelic.com
js-agent.newrelic.com
Other
135ms
30 KB
—
$2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
134ms
125 KB
56%
$2/mo
Optional
Facebook Pixel
connect.facebook.net
Advertising
108ms
97 KB
45%
$1/mo
Optional
cdn.feathr.co
cdn.feathr.co
Other
101ms
42 KB
—
$1/mo
Optional
static.cloudflareinsights.com
static.cloudflareinsights.com
Other
68ms
11 KB
—
$1/mo
Optional
Facebook Pixel
connect.facebook.net
Advertising
58ms
45 KB
46%
$1/mo
Optional
Google Analytics
www.google-analytics.com
Analytics
57ms
21 KB
—
$1/mo
Optional
code.jquery.com
code.jquery.com
Other
56ms
31 KB
—
$1/mo
Optional
www.agu.org
Other
Costly
Execution1396ms
Transfer4413 KB
Monthly Cost$19/mo
www.agu.org
Other
Costly
Execution777ms
Transfer58 KB
Monthly Cost$10/mo
Unattributable
Other
Costly
Execution685ms
Transfer0 KB
Monthly Cost$9/mo
www.agu.org
Other
Costly
Execution570ms
Transfer707 KB
Monthly Cost$8/mo
www.agu.org
Other
Costly
Execution432ms
Transfer624 KB
Monthly Cost$6/mo
www.agu.org
Other
Costly
Execution422ms
Transfer467 KB
Monthly Cost$6/mo
Google Tag Manager
Tag Manager
Costly
Execution403ms
Transfer177 KB
Unused34%
Monthly Cost$5/mo
www.agu.org
Other
Costly
Execution260ms
Transfer143 KB
Unused76%
Monthly Cost$3/mo
Google Tag Manager
Tag Manager
Optional
Execution172ms
Transfer149 KB
Unused55%
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Optional
Execution170ms
Transfer137 KB
Unused47%
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Optional
Execution143ms
Transfer137 KB
Unused51%
Monthly Cost$2/mo
Hotjar
Session Replay
Optional
Execution137ms
Transfer57 KB
Unused65%
Monthly Cost$2/mo
js-agent.newrelic.com
Other
Optional
Execution135ms
Transfer30 KB
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Optional
Execution134ms
Transfer125 KB
Unused56%
Monthly Cost$2/mo
Facebook Pixel
Advertising
Optional
Execution108ms
Transfer97 KB
Unused45%
Monthly Cost$1/mo
cdn.feathr.co
Other
Optional
Execution101ms
Transfer42 KB
Monthly Cost$1/mo
static.cloudflareinsights.com
Other
Optional
Execution68ms
Transfer11 KB
Monthly Cost$1/mo
Facebook Pixel
Advertising
Optional
Execution58ms
Transfer45 KB
Unused46%
Monthly Cost$1/mo
Google Analytics
Analytics
Optional
Execution57ms
Transfer21 KB
Monthly Cost$1/mo
code.jquery.com
Other
Optional
Execution56ms
Transfer31 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
www.agu.org adds 1396ms and costs ~$19/month
www.agu.org adds 777ms and costs ~$10/month
Unattributable adds 685ms and costs ~$9/month
www.agu.org adds 570ms and costs ~$8/month
www.agu.org adds 432ms and costs ~$6/month
www.agu.org adds 422ms and costs ~$6/month
Google Tag Manager adds 403ms and costs ~$5/month
www.agu.org adds 260ms and costs ~$3/month
100% 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.agu.org takes 1396ms 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
www.agu.org takes 777ms 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
Unattributable takes 685ms 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
www.agu.org takes 570ms 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
www.agu.org takes 432ms 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
www.agu.org takes 422ms 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 403ms 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
www.agu.org takes 260ms 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
76% of www.agu.org'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.
Source: web.dev
55% of Google Tag Manager'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.
Source: web.dev
51% of Google Tag Manager'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.
Source: web.dev
65% of Hotjar'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.
Source: web.dev
56% of Google Tag Manager'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.