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.
B
Image Optimization
37 images, 0 KB saveable
REVIEW
37 images, 0 KB saveable
Info::
✓
All images are well-optimized
37images578 KB
0oversized-0 KB
31legacy format
0missing dimensionsCLS risk
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
5 fonts (142 KB)
PASS
5 fonts (142 KB)
Info::
i
5 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
5
142 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
Montserrat-Regular-vari...woff2swap
Size35 KB
Load time67 ms
Start1.2 s
RiskFOUT — text flashes from fallback to web font
Karla-Regular-variable....woff2swap
Size32 KB
Load time66 ms
Start1.2 s
RiskFOUT — text flashes from fallback to web font
Karla-Italic-variable.w...woff2swap
Size33 KB
Load time67 ms
Start1.2 s
RiskFOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX...woff2swap
Size42 KB
Load time70 ms
Start3.4 s
RiskFOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX...woff2swap
Size0 KB
Load time70 ms
Start3.4 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+
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
Network Waterfall
120 requests over 5328ms
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-party8154ms · 2563KB · $108/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
2120ms
106 KB
—
$28/mo
Costly
Unattributable
Unattributable
Other
1014ms
0 KB
—
$13/mo
Costly
72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.com
72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.com
Other
691ms
501 KB
55%
$9/mo
Costly
pm-widget.taboola.com
pm-widget.taboola.com
Other
551ms
24 KB
—
$7/mo
Costly
HubSpot Analytics
js.hs-analytics.net
Analytics
429ms
42 KB
—
$6/mo
Costly
cdn.p-n.io
cdn.p-n.io
Other
329ms
46 KB
—
$4/mo
Costly
assets.iflscience.com
assets.iflscience.com
Other
302ms
364 KB
81%
$4/mo
Costly
cdn.taboola.com
cdn.taboola.com
Other
300ms
320 KB
63%
$4/mo
Costly
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
245ms
70 KB
53%
$3/mo
Costly
cdn.intergient.com
cdn.intergient.com
Other
212ms
222 KB
86%
$3/mo
Costly
cdn.iflscience.com
cdn.iflscience.com
Other
207ms
133 KB
60%
$3/mo
Costly
cdn.cxense.com
cdn.cxense.com
Other
203ms
38 KB
58%
$3/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
200ms
132 KB
48%
$3/mo
Costly
www.iflscience.com
www.iflscience.com
Other
198ms
30 KB
—
$3/mo
Optional
securepubads.g.doubleclick.net
securepubads.g.doubleclick.net
Other
179ms
188 KB
74%
$2/mo
Optional
Google Tag Manager
www.googletagmanager.com
Tag Manager
148ms
154 KB
55%
$2/mo
Optional
Twitter/X Embed
platform.twitter.com
Social
146ms
27 KB
—
$2/mo
Optional
js.trendmd.com
js.trendmd.com
Other
142ms
69 KB
46%
$2/mo
Optional
auth.iflscience.com
auth.iflscience.com
Other
122ms
1 KB
—
$2/mo
Optional
www.npttech.com
www.npttech.com
Other
106ms
3 KB
—
$1/mo
Optional
js.trendmd.com
js.trendmd.com
Other
93ms
4 KB
—
$1/mo
Optional
securepubads.g.doubleclick.net
securepubads.g.doubleclick.net
Other
84ms
34 KB
—
$1/mo
Optional
js.hubspot.com
js.hubspot.com
Other
67ms
28 KB
—
$1/mo
Optional
js.hscollectedforms.net
js.hscollectedforms.net
Other
64ms
26 KB
—
$1/mo
Optional
fundingchoicesmessages.google.com
Other
Costly
Execution2120ms
Transfer106 KB
Monthly Cost$28/mo
Unattributable
Other
Costly
Execution1014ms
Transfer0 KB
Monthly Cost$13/mo
72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.com
Other
Costly
Execution691ms
Transfer501 KB
Unused55%
Monthly Cost$9/mo
pm-widget.taboola.com
Other
Costly
Execution551ms
Transfer24 KB
Monthly Cost$7/mo
HubSpot Analytics
Analytics
Costly
Execution429ms
Transfer42 KB
Monthly Cost$6/mo
cdn.p-n.io
Other
Costly
Execution329ms
Transfer46 KB
Monthly Cost$4/mo
assets.iflscience.com
Other
Costly
Execution302ms
Transfer364 KB
Unused81%
Monthly Cost$4/mo
cdn.taboola.com
Other
Costly
Execution300ms
Transfer320 KB
Unused63%
Monthly Cost$4/mo
fundingchoicesmessages.google.com
Other
Costly
Execution245ms
Transfer70 KB
Unused53%
Monthly Cost$3/mo
cdn.intergient.com
Other
Costly
Execution212ms
Transfer222 KB
Unused86%
Monthly Cost$3/mo
cdn.iflscience.com
Other
Costly
Execution207ms
Transfer133 KB
Unused60%
Monthly Cost$3/mo
cdn.cxense.com
Other
Costly
Execution203ms
Transfer38 KB
Unused58%
Monthly Cost$3/mo
Google Tag Manager
Tag Manager
Costly
Execution200ms
Transfer132 KB
Unused48%
Monthly Cost$3/mo
www.iflscience.com
Other
Optional
Execution198ms
Transfer30 KB
Monthly Cost$3/mo
securepubads.g.doubleclick.net
Other
Optional
Execution179ms
Transfer188 KB
Unused74%
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Optional
Execution148ms
Transfer154 KB
Unused55%
Monthly Cost$2/mo
Twitter/X Embed
Social
Optional
Execution146ms
Transfer27 KB
Monthly Cost$2/mo
js.trendmd.com
Other
Optional
Execution142ms
Transfer69 KB
Unused46%
Monthly Cost$2/mo
auth.iflscience.com
Other
Optional
Execution122ms
Transfer1 KB
Monthly Cost$2/mo
www.npttech.com
Other
Optional
Execution106ms
Transfer3 KB
Monthly Cost$1/mo
js.trendmd.com
Other
Optional
Execution93ms
Transfer4 KB
Monthly Cost$1/mo
securepubads.g.doubleclick.net
Other
Optional
Execution84ms
Transfer34 KB
Monthly Cost$1/mo
js.hubspot.com
Other
Optional
Execution67ms
Transfer28 KB
Monthly Cost$1/mo
js.hscollectedforms.net
Other
Optional
Execution64ms
Transfer26 KB
Monthly Cost$1/mo
These scripts may cost more than they're worth
fundingchoicesmessages.google.com adds 2120ms and costs ~$28/month
Unattributable adds 1014ms and costs ~$13/month
72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.com adds 691ms and costs ~$9/month
pm-widget.taboola.com adds 551ms and costs ~$7/month
HubSpot Analytics adds 429ms and costs ~$6/month
cdn.p-n.io adds 329ms and costs ~$4/month
assets.iflscience.com adds 302ms and costs ~$4/month
cdn.taboola.com adds 300ms and costs ~$4/month
fundingchoicesmessages.google.com adds 245ms and costs ~$3/month
cdn.intergient.com adds 212ms and costs ~$3/month
cdn.iflscience.com adds 207ms and costs ~$3/month
cdn.cxense.com adds 203ms and costs ~$3/month
Google Tag Manager adds 200ms 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
fundingchoicesmessages.google.com takes 2120ms 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 1014ms 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
72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.com takes 691ms 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
55% of 72c64c5a2a0b.f254853b.eu-west-1.token.awswaf.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.
Source: web.dev
pm-widget.taboola.com takes 551ms 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
HubSpot Analytics takes 429ms 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
cdn.p-n.io takes 329ms 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
assets.iflscience.com takes 302ms 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
81% of assets.iflscience.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.
Source: web.dev
cdn.taboola.com takes 300ms 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
63% of cdn.taboola.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.
Source: web.dev
fundingchoicesmessages.google.com takes 245ms 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 fundingchoicesmessages.google.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.
Source: web.dev
cdn.intergient.com takes 212ms 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
86% of cdn.intergient.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.
Source: web.dev
cdn.iflscience.com takes 207ms 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
60% of cdn.iflscience.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.
Source: web.dev
cdn.cxense.com takes 203ms 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
58% of cdn.cxense.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.
Source: web.dev
Google Tag Manager takes 200ms 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
74% of securepubads.g.doubleclick.net'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.