Skip to content
https://Transport.bluei.io

Performance

· 22 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
90
GRADE
A
FIX
1
REVIEW
3
PASS
15
INFO
3

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

Mobile Desktop
97
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.
77
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
83
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.

946 ms

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

1.08 s

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

0 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.

946 ms

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

1.08 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
22
15 PASS 3 REVIEW 1 FIX
F
JS Bundles
Action
6 scripts, 611 KB unused
FIX
6 scripts, 611 KB unused
Warning::
https://transport.bluei.io/assets/index-QF_35YD0.j...: 305 KB unused (80%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://transport.bluei.io/assets/index-QF_35YD0.j...: 305 KB unused (80%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 611 KB
611 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://transport.bluei.io/assets/index-QF_35YD0.js382 KB305 KB (80%)✓1st
https://transport.bluei.io/assets/index-QF_35YD0.js0 KB305 KB (80%)✓1st
https://transport.bluei.io/registerSW.js1 KB—✓1st
https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js?11 KB—✓1st
https://transport.bluei.io/registerSW.js0 KB—✓1st
https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js?0 KB—✓1st

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

C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
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
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
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
HTTP Caching
public, max-age=0
REVIEW
public, max-age=0
Info::
Cache-Control header is set
Got: public, max-age=0
Info::
Last-Modified header present
Cache-Control

public, max-age=0

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
A+
Page Weight Budget
493 KB transferred, 30 requests
PASS
493 KB transferred, 30 requests
Info::
Page weighs 3.3 MB (493 KB transferred)
Info::
30 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
493 KB / 2.4 MB budget
493 KB transferred
30 requests
0.10 g CO2 per page load
JavaScript 393.8 KiB 80%
Fonts 59.8 KiB 12%
CSS 18.1 KiB 4%
Other 12.8 KiB 3%
Other 4.0 KiB 1%
HTML 3.0 KiB 1%
Other 1.4 KiB 0%
Images 0 B 0%
0 2.4 MB 4.9 MB
Under budget
A+
Third-Party Impact
No third-party resources
PASS
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-party.
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+
Image Optimization
2 images, 0 KB saveable
PASS
2 images, 0 KB saveable
Warning::
https://transport.bluei.io/logo-white.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
2 images 0 KB
0 oversized -0 KB
0 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

A+
JS Execution Cost
380ms total JS execution
PASS
380ms total JS execution
Info::
Unattributable: 119ms CPU time
Info::
https://transport.bluei.io/cdn-cgi/challenge-platf...: 110ms CPU time
Info::
https://transport.bluei.io/assets/index-QF_35YD0.j...: 89ms CPU time
Info::
https://transport.bluei.io/login: 62ms CPU time
Info::
Third-party scripts: 119ms (31% of total)

Main Thread Breakdown

Script Evaluation 52% Other 33% Script Parsing & Compilation 9% Style & Layout 4%
ScriptTotalScriptingParse/CompileParty
Unattributable119ms1ms0ms3rd
https://transport.bluei.io/cdn-cgi/challenge-platform/scripts/jsd/main.js110ms102ms2ms1st
https://transport.bluei.io/assets/index-QF_35YD0.js89ms44ms35ms1st
https://transport.bluei.io/login62ms33ms0ms1st
A+
Font Loading
4 fonts (60 KB)
PASS
4 fonts (60 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

4

60 KB total

Render-blocking

0

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 946 ms LCP 1.1 shttps://transport.bluei.io/fonts/MuseoSans-500.otfMuseoSans-500.otf https://transport.bluei.io/fonts/MuseoSans-500.otf — 30.8 KiB — 66 ms — font-display: swaphttps://transport.bluei.io/fonts/MuseoSans-700.otfMuseoSans-700.otf https://transport.bluei.io/fonts/MuseoSans-700.otf — 0 B — 38 ms — font-display: swaphttps://transport.bluei.io/fonts/MuseoSans-500.otfMuseoSans-500.otf https://transport.bluei.io/fonts/MuseoSans-500.otf — 0 B — 0 ms — font-display: swaphttps://transport.bluei.io/fonts/MuseoSans-700.otfMuseoSans-700.otf https://transport.bluei.io/fonts/MuseoSans-700.otf — 29.1 KiB — 39 ms — font-display: swap
MuseoSans-500.otf otf swap
Size 31 KB
Load time 66 ms
Start 385 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
MuseoSans-700.otf otf swap
Size 0 KB
Load time 38 ms
Start 494 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
MuseoSans-500.otf otf swap
Size 0 KB
Load time 0 ms
Start 605 ms
Risk FOUT — text flashes from fallback to web font
  • Convert to woff2 for ~30% smaller file size
MuseoSans-700.otf otf swap
Size 29 KB
Load time 39 ms
Start 711 ms
Risk FOUT — 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 ~18 KB and ~36 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+
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
PASS
HTTP/3 advertised via Alt-Svc
Info::
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
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+
Main HTML Cache-Control
Main HTML max-age=0 (≤ 5min) is appropriate
PASS
Main HTML max-age=0 (≤ 5min) is appropriate
Info::
Main HTML max-age=0 (≤ 5min) is appropriate
Got: public, max-age=0
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
2 server-response signal(s) detected
Info::
`Vary` header declared: Origin
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
`Last-Modified` present -- timestamp-based conditional GET supported
Consider also setting `ETag` for stronger revalidation -- ETags are content hashes that don't suffer from clock-skew or DST issues. Last-Modified alone is functional for conditional GETs and not a bug.
A
Page Weight Inventory
30 resources · 493 KB · 611 KB savings available
PASS
30 resources · 493 KB · 611 KB savings available
Info::
Within 1MB page-weight target
Got: 493 KB
Info::
~611 KB of savings available
Info::
2 third-party resources (0% of weight)
Info::
1 resources over 200KB
30 resources · 493.0 KiB · 2 third-party Within 1MB page-weight target
JavaScript 80% · 393.8 KiB
Font 12% · 59.8 KiB
CSS 4% · 18.1 KiB
Image 3% · 12.6 KiB
Other 1% · 5.7 KiB
Document 1% · 3.0 KiB

~610.6 KiB of savings available

Remove unused JavaScript: 610.6 KiB
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
30 requests over 802ms
INFO
0 ms 500 ms 1.0 s FCP 946 ms LCP 1.1 shttps://transport.bluei.io// https://transport.bluei.io/ — 200 — 1.5 KiB — 123 ms — h3https://transport.bluei.io/assets/index-QF_35YD0.js/assets/index-QF_35YD0.js https://transport.bluei.io/assets/index-QF_35YD0.js — 200 — 382.5 KiB — 162 ms — h3https://transport.bluei.io/assets/index-DwqDVZLL.css/assets/index-DwqDVZLL.css https://transport.bluei.io/assets/index-DwqDVZLL.css — 200 — 18.1 KiB — 90 ms — h3https://transport.bluei.io/registerSW.js/registerSW.js https://transport.bluei.io/registerSW.js — 200 — 736 B — 85 ms — h3https://transport.bluei.io/manifest.webmanifest/manifest.webmanifest https://transport.bluei.io/manifest.webmanifest — 200 — 888 B — 66 ms — h3data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAQAAAAfQ//73v/+BiOh/AAA=data:image/webp;base64,UklGRh4AAABX... data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAQAAAAfQ//73v/+BiOh/AAA= — 200 — 0 B — 0 ms — datahttps://transport.bluei.io/cdn-cgi/challenge-platform/scripts/jsd/main.js/cdn-cgi/challenge-platform/scripts... https://transport.bluei.io/cdn-cgi/challenge-platform/scripts/jsd/main.js — 302 — 223 B — 22 ms — h3https://transport.bluei.io/fonts/MuseoSans-500.otf/fonts/MuseoSans-500.otf https://transport.bluei.io/fonts/MuseoSans-500.otf — 200 — 30.8 KiB — 66 ms — h3https://transport.bluei.io/api/settings/api/settings https://transport.bluei.io/api/settings — 401 — 617 B — 47 ms — h3https://transport.bluei.io/api/auth/me/api/auth/me https://transport.bluei.io/api/auth/me — 401 — 615 B — 39 ms — h3https://transport.bluei.io/favicon.png/favicon.png https://transport.bluei.io/favicon.png — 200 — 12.6 KiB — 49 ms — h3https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js?/cdn-cgi/challenge-platform/h/g/scr... https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js? — 200 — 10.6 KiB — 22 ms — h3https://transport.bluei.io/favicon.png/favicon.png https://transport.bluei.io/favicon.png — 200 — 0 B — 48 ms — h3https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/jsd/oneshot/fe6331af5207/0.3460538606720116:1778412121:f3tinvcm9bi-2i_THhrHz-7o_qQR-Y7EaZ4f1YElj1k/9f98cc381f44ebac/cdn-cgi/challenge-platform/h/g/jsd... https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/jsd/oneshot/fe6331af5207/0.3460538606720116:1778412121:f3tinvcm9bi-2i_THhrHz-7o_qQR-Y7EaZ4f1YElj1k/9f98cc381f44ebac — 200 — 838 B — 24 ms — h3https://transport.bluei.io/login/login https://transport.bluei.io/login — 200 — 1.5 KiB — 39 ms — h3https://transport.bluei.io/logo-white.png/logo-white.png https://transport.bluei.io/logo-white.png — -1 — 0 B — 39 ms — https://transport.bluei.io/fonts/MuseoSans-700.otf/fonts/MuseoSans-700.otf https://transport.bluei.io/fonts/MuseoSans-700.otf — -1 — 0 B — 38 ms — https://transport.bluei.io/assets/index-QF_35YD0.js/assets/index-QF_35YD0.js https://transport.bluei.io/assets/index-QF_35YD0.js — 200 — 0 B — 0 ms — h3https://transport.bluei.io/assets/index-DwqDVZLL.css/assets/index-DwqDVZLL.css https://transport.bluei.io/assets/index-DwqDVZLL.css — 200 — 0 B — 0 ms — h3https://transport.bluei.io/registerSW.js/registerSW.js https://transport.bluei.io/registerSW.js — 200 — 0 B — 0 ms — h3https://transport.bluei.io/fonts/MuseoSans-500.otf/fonts/MuseoSans-500.otf https://transport.bluei.io/fonts/MuseoSans-500.otf — 200 — 0 B — 0 ms — h3data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAQAAAAfQ//73v/+BiOh/AAA=data:image/webp;base64,UklGRh4AAABX... data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAQAAAAfQ//73v/+BiOh/AAA= — 200 — 0 B — 0 ms — datahttps://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js?/cdn-cgi/challenge-platform/h/g/scr... https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/scripts/jsd/fe6331af5207/main.js? — 200 — 0 B — 0 ms — h3https://transport.bluei.io/logo-white.png/logo-white.png https://transport.bluei.io/logo-white.png — 200 — 0 B — 4 ms — h3https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/jsd/oneshot/fe6331af5207/0.3460538606720116:1778412121:f3tinvcm9bi-2i_THhrHz-7o_qQR-Y7EaZ4f1YElj1k/9f98cc3affd2ebac/cdn-cgi/challenge-platform/h/g/jsd... https://transport.bluei.io/cdn-cgi/challenge-platform/h/g/jsd/oneshot/fe6331af5207/0.3460538606720116:1778412121:f3tinvcm9bi-2i_THhrHz-7o_qQR-Y7EaZ4f1YElj1k/9f98cc3affd2ebac — 200 — 840 B — 24 ms — h3https://transport.bluei.io/fonts/MuseoSans-700.otf/fonts/MuseoSans-700.otf https://transport.bluei.io/fonts/MuseoSans-700.otf — 200 — 29.1 KiB — 39 ms — h3https://transport.bluei.io/manifest.webmanifest/manifest.webmanifest https://transport.bluei.io/manifest.webmanifest — 200 — 582 B — 43 ms — h3https://transport.bluei.io/api/settings/api/settings https://transport.bluei.io/api/settings — 401 — 612 B — 41 ms — h3https://transport.bluei.io/api/auth/me/api/auth/me https://transport.bluei.io/api/auth/me — 401 — 610 B — 41 ms — h3https://transport.bluei.io/favicon.png/favicon.png https://transport.bluei.io/favicon.png — 200 — 0 B — 42 ms — h3
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
31% of JavaScript execution is third-party
First-party Third-party 119ms · 0KB · £1/mo
Unattributable
Other
Optional
Execution 119ms
Transfer 0 KB
Monthly Cost £1/mo

How third-party costs are calculated

Image Optimization
1 images, 25 KB total, 25 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

25 KB

Oversized

1

Wasted

25 KB

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

Send Feedback