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Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
77
GRADE
C
FIX
5
REVIEW
3
PASS
7
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
41
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
97
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
100
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

5.28 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

9.01 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

907 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.000

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

5.28 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

11.70 s

Page Load Progression

375 ms
750 ms
1.1 s
1.5 s
1.9 s
2.2 s
2.6 s
3.0 s
Checks
17
7 PASS 3 REVIEW 5 FIX
D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (1.5 MiB of 1.5 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
D
JS Execution Cost
Action
3185ms total JS execution
FIX
3185ms total JS execution
Warning::
https://www.gla.ac.uk/: 919ms CPU time
Warning::
https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350...: 776ms CPU time
Warning::
https://www.gla.ac.uk/3t4/css/main.css?_=177635021...: 344ms CPU time
Warning::
Unattributable: 265ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-K4S...: 227ms CPU time
Warning::
Third-party scripts: 3185ms (100% of total)

Main Thread Breakdown

Script Evaluation 29% Other 26% Style & Layout 23% Parse HTML & CSS 10% Script Parsing & Compilation 7% Rendering 4%
ScriptTotalScriptingParse/CompileParty
https://www.gla.ac.uk/919ms12ms3ms3rd
https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210776ms265ms52ms3rd
https://www.gla.ac.uk/3t4/css/main.css?_=1776350210344ms0ms0ms3rd
Unattributable265ms7ms0ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4227ms162ms45ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1206ms157ms47ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1189ms154ms33ms3rd
https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1159ms126ms32ms3rd
https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.js101ms30ms1ms3rd
D
JS Bundles
Action
10 scripts, 373 KB unused
FIX
10 scripts, 373 KB unused
Warning::
https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350...: 100 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-K4S...: 78 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-112...: 66 KB unused (46%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=AW-109...: 65 KB unused (45%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=DC-840...: 64 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 373 KB
373 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210182 KB100 KB (55%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4170 KB78 KB (46%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1145 KB66 KB (46%)✓3rd
https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1146 KB65 KB (45%)✓3rd
https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1130 KB64 KB (49%)✓3rd
https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.js4 KB—✓3rd
https://www.gla.ac.uk/3t4/js/dist/gu-newsfeed.a21f457c.js1 KB—✓3rd
https://www.gla.ac.uk/3t4/js/dist/gu-wrapper.992b5522.js2 KB—✓3rd
https://www.gla.ac.uk/3t4/js/dist/gu-autocomplete.2bd84e71.js1 KB—✓3rd
https://www.gla.ac.uk/3t4/js/dist/gu-events-tile.5a330ec5.js5 KB—✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

Consider code splitting or tree shaking to reduce unused code.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

D
Page Weight Inventory
Action
36 resources · 1.5 MB · 373 KB savings available
FIX
36 resources · 1.5 MB · 373 KB savings available
Warning::
Page weight 464 KB over 1MB target
Got: 1.5 MB Expected: ≤ 1 MB
Info::
~373 KB of savings available
Warning::
35 third-party resources (100% of weight)
Info::
1 resources over 200KB
36 resources · 1.5 MiB · 35 third-party 463.7 KiB over 1MB target
JavaScript 53% · 784.2 KiB
CSS 29% · 429.9 KiB
Image 12% · 176.9 KiB
Font 5% · 73.8 KiB
Document 1% · 22.0 KiB
Other 0% · 922 B

~372.8 KiB of savings available

Remove unused JavaScript: 372.8 KiB
F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
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
Page Weight Budget
1.5 MB transferred, 36 requests
REVIEW
1.5 MB transferred, 36 requests
Info::
Page weighs 6.8 MB (1.5 MB transferred)
Warning::
JavaScript is 784 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 784 KB
Info::
CSS is 430 KB — consider purging unused styles
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
Got: 430 KB
Info::
36 HTTP requests
Info::
Estimated 0.30 g CO2 per page load
1.5 MB / 2.4 MB budget
1.5 MB transferred
36 requests
0.30 g CO2 per page load
JavaScript 784.2 KiB 53%
CSS 429.9 KiB 29%
Images 175.5 KiB 12%
Fonts 73.8 KiB 5%
HTML 20.8 KiB 1%
Other 1.8 KiB 0%
Other 1.6 KiB 0%
0 2.4 MB 4.9 MB
Under budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.

Why this matters

CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.

Source: web.dev

B
Image Optimization
11 images, 0 KB saveable
REVIEW
11 images, 0 KB saveable
Warning::
https://www.gla.ac.uk/3t4/img/575.svg is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
11 images 176 KB
0 oversized -0 KB
9 legacy format
1 missing dimensions CLS 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

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
2 fonts (74 KB)
PASS
2 fonts (74 KB)
Info::
2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

2

74 KB total

Render-blocking

0

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 5.3 s LCP 9.0 shttps://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2o-0bIpQlx3QUlC5A4PNB6Ry... https://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2 — 35.0 KiB — 56 ms — font-display: swaphttps://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2o-0ZIpQlx3QUlC5A4PNr4C5... https://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2 — 38.7 KiB — 56 ms — font-display: swap
o-0bIpQlx3QUlC5A4PNB6Ry... woff2 swap
Size 35 KB
Load time 56 ms
Start 951 ms
Risk FOUT — text flashes from fallback to web font
o-0ZIpQlx3QUlC5A4PNr4C5... woff2 swap
Size 39 KB
Load time 56 ms
Start 951 ms
Risk FOUT — 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
1 hints, 0 missing preconnects
PASS
1 hints, 0 missing preconnects
Info::
Page uses 1 resource hint(s)

Current Resource Hints

preconnect
—
preload
1
dns-prefetch
—
prefetch
—

1 resource hints configured

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
36 requests over 1275ms
INFO
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 5.3 s LCP 9.0 shttps://gla.ac.uk// https://gla.ac.uk/ — 301 — 243 B — 117 ms — http/1.1https://www.gla.ac.uk/www.gla.ac.uk/ https://www.gla.ac.uk/ — 200 — 20.8 KiB — 157 ms — http/1.1https://www.gla.ac.uk/3t4/css/font-awesome.min.csswww.gla.ac.uk/3t4/css/font-awesome.... https://www.gla.ac.uk/3t4/css/font-awesome.min.css — 200 — 6.9 KiB — 67 ms — http/1.1https://www.gla.ac.uk/3t4/img/cog-white.svgwww.gla.ac.uk/3t4/img/cog-white.svg https://www.gla.ac.uk/3t4/img/cog-white.svg — 200 — 1.6 KiB — 117 ms — http/1.1https://www.gla.ac.uk/3t4/img/ug-keyline.svgwww.gla.ac.uk/3t4/img/ug-keyline.sv... https://www.gla.ac.uk/3t4/img/ug-keyline.svg — 200 — 3.3 KiB — 120 ms — http/1.1https://www.gla.ac.uk/3t4/img/ug-keyline-large.svgwww.gla.ac.uk/3t4/img/ug-keyline-la... https://www.gla.ac.uk/3t4/img/ug-keyline-large.svg — 200 — 6.0 KiB — 126 ms — http/1.1https://www.gla.ac.uk/3t4/img/575.svgwww.gla.ac.uk/3t4/img/575.svg https://www.gla.ac.uk/3t4/img/575.svg — 200 — 5.2 KiB — 126 ms — http/1.1https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4www.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4 — 200 — 169.6 KiB — 176 ms — h2https://www.gla.ac.uk/3t4/css/print.csswww.gla.ac.uk/3t4/css/print.css https://www.gla.ac.uk/3t4/css/print.css — 200 — 818 B — 124 ms — http/1.1https://www.gla.ac.uk/3t4/css/main.css?_=1776350210www.gla.ac.uk/3t4/css/main.css?_=17... https://www.gla.ac.uk/3t4/css/main.css?_=1776350210 — 200 — 420.4 KiB — 245 ms — http/1.1https://www.gla.ac.uk/3t4/img/svh.webpwww.gla.ac.uk/3t4/img/svh.webp https://www.gla.ac.uk/3t4/img/svh.webp — 200 — 27.0 KiB — 77 ms — http/1.1https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210www.gla.ac.uk/3t4/js/main.min.js?_=... https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210 — 200 — 182.5 KiB — 156 ms — http/1.1https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1 — 200 — 145.6 KiB — 62 ms — h2https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1 — 200 — 144.8 KiB — 72 ms — h2https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1 — 200 — 130.1 KiB — 48 ms — h2https://fonts.googleapis.com/css2?family=Noto+Sans:ital,wght@0,400;0,700;1,400;1,700&display=swapfonts.googleapis.com/css2?family=No... https://fonts.googleapis.com/css2?family=Noto+Sans:ital,wght@0,400;0,700;1,400;1,700&display=swap — 200 — 1.4 KiB — 100 ms — h2https://www.gla.ac.uk/3t4/img/arrow-thick-right.svgwww.gla.ac.uk/3t4/img/arrow-thick-r... https://www.gla.ac.uk/3t4/img/arrow-thick-right.svg — 200 — 625 B — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thin-blue.svgwww.gla.ac.uk/3t4/img/arrow-thin-bl... https://www.gla.ac.uk/3t4/img/arrow-thin-blue.svg — 200 — 730 B — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/ukraine-flag.pngwww.gla.ac.uk/3t4/img/ukraine-flag.... https://www.gla.ac.uk/3t4/img/ukraine-flag.png — 200 — 1.3 KiB — 42 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thick-right.pngwww.gla.ac.uk/3t4/img/arrow-thick-r... https://www.gla.ac.uk/3t4/img/arrow-thick-right.png — 200 — 1.3 KiB — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thin-white.svgwww.gla.ac.uk/3t4/img/arrow-thin-wh... https://www.gla.ac.uk/3t4/img/arrow-thin-white.svg — 200 — 623 B — 46 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.jswww.gla.ac.uk/3t4/js/dist/gu-tiles.... https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.js — 200 — 3.5 KiB — 41 ms — http/1.1https://fonts.googleapis.com/icon?family=Material+Iconsfonts.googleapis.com/icon?family=Ma... https://fonts.googleapis.com/icon?family=Material+Icons — 200 — 446 B — 26 ms — h2https://www.gla.ac.uk/3t4/js/dist/gu-newsfeed.a21f457c.jswww.gla.ac.uk/3t4/js/dist/gu-newsfe... https://www.gla.ac.uk/3t4/js/dist/gu-newsfeed.a21f457c.js — 200 — 1023 B — 45 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-wrapper.992b5522.jswww.gla.ac.uk/3t4/js/dist/gu-wrappe... https://www.gla.ac.uk/3t4/js/dist/gu-wrapper.992b5522.js — 200 — 1.7 KiB — 42 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-autocomplete.2bd84e71.jswww.gla.ac.uk/3t4/js/dist/gu-autoco... https://www.gla.ac.uk/3t4/js/dist/gu-autocomplete.2bd84e71.js — 200 — 970 B — 44 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-events-tile.5a330ec5.jswww.gla.ac.uk/3t4/js/dist/gu-events... https://www.gla.ac.uk/3t4/js/dist/gu-events-tile.5a330ec5.js — 200 — 4.5 KiB — 46 ms — http/1.1https://cfmnsugzia.cloudimg.io/www.gla.ac.uk/media/Media_1141038_smxx.webp?width=1400&force_format=webpcfmnsugzia.cloudimg.io/www.gla.ac.u... https://cfmnsugzia.cloudimg.io/www.gla.ac.uk/media/Media_1141038_smxx.webp?width=1400&force_format=webp — 200 — 128.0 KiB — 97 ms — h2https://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2fonts.gstatic.com/s/notosans/v42/o-... https://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2 — 200 — 35.0 KiB — 56 ms — h3https://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2fonts.gstatic.com/s/notosans/v42/o-... https://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2 — 200 — 38.7 KiB — 56 ms — h3
0 ms 1.0 s 2.0 s 3.0 s 4.0 s 5.0 s 6.0 s 7.0 s 8.0 s 9.0 s FCP 5.3 s LCP 9.0 shttps://gla.ac.uk// https://gla.ac.uk/ — 301 — 243 B — 117 ms — http/1.1https://www.gla.ac.uk/www.gla.ac.uk/ https://www.gla.ac.uk/ — 200 — 20.8 KiB — 157 ms — http/1.1https://www.gla.ac.uk/3t4/css/font-awesome.min.csswww.gla.ac.uk/3t4/css/font-awesome.... https://www.gla.ac.uk/3t4/css/font-awesome.min.css — 200 — 6.9 KiB — 67 ms — http/1.1https://www.gla.ac.uk/3t4/img/cog-white.svgwww.gla.ac.uk/3t4/img/cog-white.svg https://www.gla.ac.uk/3t4/img/cog-white.svg — 200 — 1.6 KiB — 117 ms — http/1.1https://www.gla.ac.uk/3t4/img/ug-keyline.svgwww.gla.ac.uk/3t4/img/ug-keyline.sv... https://www.gla.ac.uk/3t4/img/ug-keyline.svg — 200 — 3.3 KiB — 120 ms — http/1.1https://www.gla.ac.uk/3t4/img/ug-keyline-large.svgwww.gla.ac.uk/3t4/img/ug-keyline-la... https://www.gla.ac.uk/3t4/img/ug-keyline-large.svg — 200 — 6.0 KiB — 126 ms — http/1.1https://www.gla.ac.uk/3t4/img/575.svgwww.gla.ac.uk/3t4/img/575.svg https://www.gla.ac.uk/3t4/img/575.svg — 200 — 5.2 KiB — 126 ms — http/1.1https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4www.googletagmanager.com/gtm.js?id=... https://www.googletagmanager.com/gtm.js?id=GTM-K4S47B4 — 200 — 169.6 KiB — 176 ms — h2https://www.gla.ac.uk/3t4/css/print.csswww.gla.ac.uk/3t4/css/print.css https://www.gla.ac.uk/3t4/css/print.css — 200 — 818 B — 124 ms — http/1.1https://www.gla.ac.uk/3t4/css/main.css?_=1776350210www.gla.ac.uk/3t4/css/main.css?_=17... https://www.gla.ac.uk/3t4/css/main.css?_=1776350210 — 200 — 420.4 KiB — 245 ms — http/1.1https://www.gla.ac.uk/3t4/img/svh.webpwww.gla.ac.uk/3t4/img/svh.webp https://www.gla.ac.uk/3t4/img/svh.webp — 200 — 27.0 KiB — 77 ms — http/1.1https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210www.gla.ac.uk/3t4/js/main.min.js?_=... https://www.gla.ac.uk/3t4/js/main.min.js?_=1776350210 — 200 — 182.5 KiB — 156 ms — http/1.1https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=AW-10932928603&cx=c&gtm=4e64h1 — 200 — 145.6 KiB — 62 ms — h2https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=AW-11245383745&cx=c&gtm=4e64h1 — 200 — 144.8 KiB — 72 ms — h2https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1www.googletagmanager.com/gtag/js?id... https://www.googletagmanager.com/gtag/js?id=DC-8408918&cx=c&gtm=4e64h1 — 200 — 130.1 KiB — 48 ms — h2https://fonts.googleapis.com/css2?family=Noto+Sans:ital,wght@0,400;0,700;1,400;1,700&display=swapfonts.googleapis.com/css2?family=No... https://fonts.googleapis.com/css2?family=Noto+Sans:ital,wght@0,400;0,700;1,400;1,700&display=swap — 200 — 1.4 KiB — 100 ms — h2https://www.gla.ac.uk/3t4/img/arrow-thick-right.svgwww.gla.ac.uk/3t4/img/arrow-thick-r... https://www.gla.ac.uk/3t4/img/arrow-thick-right.svg — 200 — 625 B — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thin-blue.svgwww.gla.ac.uk/3t4/img/arrow-thin-bl... https://www.gla.ac.uk/3t4/img/arrow-thin-blue.svg — 200 — 730 B — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/ukraine-flag.pngwww.gla.ac.uk/3t4/img/ukraine-flag.... https://www.gla.ac.uk/3t4/img/ukraine-flag.png — 200 — 1.3 KiB — 42 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thick-right.pngwww.gla.ac.uk/3t4/img/arrow-thick-r... https://www.gla.ac.uk/3t4/img/arrow-thick-right.png — 200 — 1.3 KiB — 41 ms — http/1.1https://www.gla.ac.uk/3t4/img/arrow-thin-white.svgwww.gla.ac.uk/3t4/img/arrow-thin-wh... https://www.gla.ac.uk/3t4/img/arrow-thin-white.svg — 200 — 623 B — 46 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.jswww.gla.ac.uk/3t4/js/dist/gu-tiles.... https://www.gla.ac.uk/3t4/js/dist/gu-tiles.031eb899.js — 200 — 3.5 KiB — 41 ms — http/1.1https://fonts.googleapis.com/icon?family=Material+Iconsfonts.googleapis.com/icon?family=Ma... https://fonts.googleapis.com/icon?family=Material+Icons — 200 — 446 B — 26 ms — h2https://www.gla.ac.uk/3t4/js/dist/gu-newsfeed.a21f457c.jswww.gla.ac.uk/3t4/js/dist/gu-newsfe... https://www.gla.ac.uk/3t4/js/dist/gu-newsfeed.a21f457c.js — 200 — 1023 B — 45 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-wrapper.992b5522.jswww.gla.ac.uk/3t4/js/dist/gu-wrappe... https://www.gla.ac.uk/3t4/js/dist/gu-wrapper.992b5522.js — 200 — 1.7 KiB — 42 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-autocomplete.2bd84e71.jswww.gla.ac.uk/3t4/js/dist/gu-autoco... https://www.gla.ac.uk/3t4/js/dist/gu-autocomplete.2bd84e71.js — 200 — 970 B — 44 ms — http/1.1https://www.gla.ac.uk/3t4/js/dist/gu-events-tile.5a330ec5.jswww.gla.ac.uk/3t4/js/dist/gu-events... https://www.gla.ac.uk/3t4/js/dist/gu-events-tile.5a330ec5.js — 200 — 4.5 KiB — 46 ms — http/1.1https://cfmnsugzia.cloudimg.io/www.gla.ac.uk/media/Media_1141038_smxx.webp?width=1400&force_format=webpcfmnsugzia.cloudimg.io/www.gla.ac.u... https://cfmnsugzia.cloudimg.io/www.gla.ac.uk/media/Media_1141038_smxx.webp?width=1400&force_format=webp — 200 — 128.0 KiB — 97 ms — h2https://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2fonts.gstatic.com/s/notosans/v42/o-... https://fonts.gstatic.com/s/notosans/v42/o-0bIpQlx3QUlC5A4PNB6Ryti20_6n1iPHjc5a7du3mhPy0.woff2 — 200 — 35.0 KiB — 56 ms — h3https://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2fonts.gstatic.com/s/notosans/v42/o-... https://fonts.gstatic.com/s/notosans/v42/o-0ZIpQlx3QUlC5A4PNr4C5OaxRsfNNlKbCePevtuXOmHS91iw.woff2 — 200 — 38.7 KiB — 56 ms — h3https://www.gla.ac.uk/news/homepage/?s=1776804894331www.gla.ac.uk/news/homepage/?s=1776... https://www.gla.ac.uk/news/homepage/?s=1776804894331 — 200 — 943 B — 44 ms — http/1.1https://www.gla.ac.uk/feeds/events/eventfeedbyid.php?ids=14499,14500,14596,14620,14621,14623,14575,14577,14578www.gla.ac.uk/feeds/events/eventfee... https://www.gla.ac.uk/feeds/events/eventfeedbyid.php?ids=14499,14500,14596,14620,14621,14623,14575,14577,14578 — 200 — 859 B — 295 ms — http/1.1https://pagead2.googlesyndication.com/ccm/collect?rcb=8&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45fe64h1v9181632528z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3qPq2q5l1&dma_cps=-&dma=1&tag_exp=0~115938465~115938469~117266400&apve=1&apvf=f&apvc=1&tids=DC-8408918&tid=DC-8408918&tft=1776804894688&tfd=1027pagead2.googlesyndication.com/ccm/c... https://pagead2.googlesyndication.com/ccm/collect?rcb=8&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45fe64h1v9181632528z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3qPq2q5l1&dma_cps=-&dma=1&tag_exp=0~115938465~115938469~117266400&apve=1&apvf=f&apvc=1&tids=DC-8408918&tid=DC-8408918&tft=1776804894688&tfd=1027 — 200 — 21 B — 132 ms — h3https://pagead2.googlesyndication.com/ccm/collect?rcb=8&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45be64h1v892630087z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3q3q2q5l1&dma_cps=-&dma=1&tag_exp=0~115616985~115938465~115938469~117266401~118463261&apve=1&apvf=f&apvc=0&tids=AW-10932928603&tid=AW-10932928603&tft=1776804894759&tfd=1099pagead2.googlesyndication.com/ccm/c... https://pagead2.googlesyndication.com/ccm/collect?rcb=8&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45be64h1v892630087z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3q3q2q5l1&dma_cps=-&dma=1&tag_exp=0~115616985~115938465~115938469~117266401~118463261&apve=1&apvf=f&apvc=0&tids=AW-10932928603&tid=AW-10932928603&tft=1776804894759&tfd=1099 — 200 — 21 B — 61 ms — h3https://pagead2.googlesyndication.com/ccm/collect?rcb=13&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45be64h1v9136155258z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3q3q2q5l1&dma_cps=-&dma=1&tag_exp=0~115938465~115938468~117266400&apve=1&apvf=f&apvc=0&tids=AW-11245383745&tid=AW-11245383745&tft=1776804894816&tfd=1155pagead2.googlesyndication.com/ccm/c... https://pagead2.googlesyndication.com/ccm/collect?rcb=13&frm=0&en=page_view&dl=https%3A%2F%2Fwww.gla.ac.uk%2F&scrsrc=www.googletagmanager.com&rnd=98511173.1776804895&navt=n&npa=1&gtm=45be64h1v9136155258z8899973860za20gzb899973860zd899973860xec&gcs=G100&gcd=13q3q3q2q5l1&dma_cps=-&dma=1&tag_exp=0~115938465~115938468~117266400&apve=1&apvf=f&apvc=0&tids=AW-11245383745&tid=AW-11245383745&tft=1776804894816&tfd=1155 — 200 — 21 B — 27 ms — h3https://www.gla.ac.uk/favicon.icowww.gla.ac.uk/favicon.ico https://www.gla.ac.uk/favicon.ico — 200 — 1.4 KiB — 43 ms — http/1.1
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-party 3185ms · 1217KB · £33/mo
www.gla.ac.uk
Other
Costly
Execution 919ms
Transfer 21 KB
Monthly Cost £10/mo
www.gla.ac.uk
Other
Costly
Execution 776ms
Transfer 182 KB
Unused 55%
Monthly Cost £8/mo
www.gla.ac.uk
Other
Costly
Execution 344ms
Transfer 420 KB
Monthly Cost £4/mo
Unattributable
Other
Costly
Execution 265ms
Transfer 0 KB
Monthly Cost £3/mo
Google Tag Manager
Tag Manager
Costly
Execution 227ms
Transfer 170 KB
Unused 46%
Monthly Cost £2/mo
Google Tag Manager
Tag Manager
Costly
Execution 206ms
Transfer 145 KB
Unused 46%
Monthly Cost £2/mo
Google Tag Manager
Tag Manager
Optional
Execution 189ms
Transfer 146 KB
Unused 45%
Monthly Cost £2/mo
Google Tag Manager
Tag Manager
Optional
Execution 159ms
Transfer 130 KB
Unused 49%
Monthly Cost £2/mo
www.gla.ac.uk
Other
Optional
Execution 101ms
Transfer 4 KB
Monthly Cost £1/mo

These scripts may cost more than they're worth

  • www.gla.ac.uk adds 919ms and costs ~£10/month
  • www.gla.ac.uk adds 776ms and costs ~£8/month
  • www.gla.ac.uk adds 344ms and costs ~£4/month
  • Unattributable adds 265ms and costs ~£3/month
  • Google Tag Manager adds 227ms and costs ~£2/month
  • Google Tag Manager adds 206ms and costs ~£2/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.gla.ac.uk takes 919ms 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.gla.ac.uk takes 776ms 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 www.gla.ac.uk'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

www.gla.ac.uk takes 344ms 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 265ms 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 227ms 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 206ms 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

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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