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https://tailwindcss.com

Performance

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

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

Mobile Desktop
81
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
86
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
91
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.

524 ms

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

2.75 s

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

102 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.

1.90 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.

2.89 s

Page Load Progression

462 ms
924 ms
1.4 s
1.8 s
2.3 s
2.8 s
3.2 s
3.7 s
Checks
14
7 PASS 3 REVIEW 2 FIX
F
Page Weight Budget
Action
7.5 MB transferred, 96 requests
FIX
7.5 MB transferred, 96 requests
Critical::
Page weighs 11.2 MB (7.5 MB transferred)
Warning::
Images are 5.4 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 5.4 MB
Info::
Fonts are 1.2 MB — consider subsetting or using system fonts
Subset fonts to include only used characters, or switch to system font stacks.
Got: 1.2 MB
Info::
96 HTTP requests
Info::
Estimated 1.6 g CO2 per page load
7.5 MB / 2.4 MB budget
7.5 MB transferred
96 requests
1.6 g CO2 per page load
Images 5.4 MiB 71%
Fonts 1.2 MiB 15%
Other 473.5 KiB 6%
JavaScript 366.2 KiB 5%
HTML 133.4 KiB 2%
CSS 79.1 KiB 1%
Other 3.5 KiB 0%
Other 824 B 0%
0 2.4 MB 4.9 MB
Over budget

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

D
JS Execution Cost
Action
2113ms total JS execution
FIX
2113ms total JS execution
Warning::
https://tailwindcss.com/: 946ms CPU time
Warning::
https://tailwindcss.com/_next/static/chunks/70e258...: 385ms CPU time
Warning::
https://tailwindcss.com/_next/static/chunks/33e576...: 383ms CPU time
Info::
Unattributable: 226ms CPU time
Info::
https://tailwindcss.com/_next/static/chunks/612016...: 172ms CPU time
Info::
Third-party scripts: 226ms (11% of total)

Main Thread Breakdown

Style & Layout 34% Script Evaluation 27% Other 25% Rendering 7% Script Parsing & Compilation 4% Parse HTML & CSS 3%
ScriptTotalScriptingParse/CompileParty
https://tailwindcss.com/946ms22ms49ms1st
https://tailwindcss.com/_next/static/chunks/70e258b44c36445b.js385ms148ms4ms1st
https://tailwindcss.com/_next/static/chunks/33e576c593493439.js383ms244ms12ms1st
Unattributable226ms30ms0ms3rd
https://tailwindcss.com/_next/static/chunks/6120162fc820413f.js172ms123ms4ms1st
B
Image Optimization
26 images, 0 KB saveable
REVIEW
26 images, 0 KB saveable
Info::
All images are well-optimized
26 images 5.4 MB
0 oversized -0 KB
26 legacy format
0 missing dimensions CLS risk
B
JS Bundles
23 scripts, 100 KB unused
REVIEW
23 scripts, 100 KB unused
Warning::
https://tailwindcss.com/_next/static/chunks/396c93...: 27 KB unused (96%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://tailwindcss.com/_next/static/chunks/16a6a8...: 25 KB unused (93%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://tailwindcss.com/_next/static/chunks/33e576...: 24 KB unused (34%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://tailwindcss.com/_next/static/chunks/918560...: 24 KB unused (100%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 100 KB
100 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://tailwindcss.com/_next/static/chunks/396c9350f71c1071.js29 KB27 KB (96%)✓1st
https://tailwindcss.com/_next/static/chunks/16a6a8ec5f5434fe.js28 KB25 KB (93%)✓1st
https://tailwindcss.com/_next/static/chunks/33e576c593493439.js70 KB24 KB (34%)✓1st
https://tailwindcss.com/_next/static/chunks/918560bfa843b51f.js24 KB24 KB (100%)✓1st
https://tailwindcss.com/_next/static/chunks/f85253431e2047ca.js12 KB—✓1st
https://tailwindcss.com/_next/static/chunks/6120162fc820413f.js33 KB—✓1st
https://tailwindcss.com/_next/static/chunks/e343ebd917f30815.js8 KB—✓1st
https://tailwindcss.com/_next/static/chunks/3999145dce13d1ea.js7 KB—✓1st
https://tailwindcss.com/_next/static/chunks/turbopack-59447e2416b3e85b.js5 KB—✓1st
https://tailwindcss.com/_next/static/chunks/bea4eec49ddd3f96.js14 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

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

B
HTTP Caching
public, max-age=0, must-revalidate
REVIEW
public, max-age=0, must-revalidate
Info::
Cache-Control header is set
Got: public, max-age=0, must-revalidate
Info::
ETag present — enables conditional (304) responses
Cache-Control

public, max-age=0, must-revalidate

DirectiveValueMeaning
public—Any cache may store this response
max-age0Cache for 0 seconds
must-revalidate—Must recheck with server after expiry
A+
Third-Party Impact
0% third-party, 0 ms blocking
PASS
0% third-party, 0 ms blocking
Info::
Third-party code accounts for 0% of page weight (3.1 KiB of 7.5 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-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+
Font Loading
10 fonts (1178 KB)
PASS
10 fonts (1178 KB)
Info::
10 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

10

1178 KB total

Render-blocking

0

of 10

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s 2.0 s 2.5 s FCP 524 ms LCP 2.8 shttps://tailwindcss.com/_next/static/media/IBMPlexMono_Italic-s.p.ddd44df2.woff2IBMPlexMono_Italic-s.p.... https://tailwindcss.com/_next/static/media/IBMPlexMono_Italic-s.p.ddd44df2.woff2 — 49.6 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/IBMPlexMono_Medium-s.p.511bc7e4.woff2IBMPlexMono_Medium-s.p.... https://tailwindcss.com/_next/static/media/IBMPlexMono_Medium-s.p.511bc7e4.woff2 — 46.2 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/IBMPlexMono_MediumItalic-s.p.824237ad.woff2IBMPlexMono_MediumItali... https://tailwindcss.com/_next/static/media/IBMPlexMono_MediumItalic-s.p.824237ad.woff2 — 50.7 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/IBMPlexMono_Regular-s.p.170fa0da.woff2IBMPlexMono_Regular-s.p... https://tailwindcss.com/_next/static/media/IBMPlexMono_Regular-s.p.170fa0da.woff2 — 45.1 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/IBMPlexMono_SemiBold-s.p.4dbcf170.woff2IBMPlexMono_SemiBold-s.... https://tailwindcss.com/_next/static/media/IBMPlexMono_SemiBold-s.p.4dbcf170.woff2 — 46.4 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/IBMPlexMono_SemiBoldItalic-s.p.63e919a5.woff2IBMPlexMono_SemiBoldIta... https://tailwindcss.com/_next/static/media/IBMPlexMono_SemiBoldItalic-s.p.63e919a5.woff2 — 50.8 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/InterVariable-s.p.53d7b668.woff2InterVariable-s.p.53d7b... https://tailwindcss.com/_next/static/media/InterVariable-s.p.53d7b668.woff2 — 344.8 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/InterVariable_Italic-s.p.8c0e9517.woff2InterVariable_Italic-s.... https://tailwindcss.com/_next/static/media/InterVariable_Italic-s.p.8c0e9517.woff2 — 379.8 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/SourceSansPro_Regular_ttf-s.p.aa178fa4.woff2SourceSansPro_Regular_t... https://tailwindcss.com/_next/static/media/SourceSansPro_Regular_ttf-s.p.aa178fa4.woff2 — 85.4 KiB — 0 ms — font-display: swaphttps://tailwindcss.com/_next/static/media/Ubuntu_Mono_bold-s.p.36063628.woff2Ubuntu_Mono_bold-s.p.36... https://tailwindcss.com/_next/static/media/Ubuntu_Mono_bold-s.p.36063628.woff2 — 79.0 KiB — 0 ms — font-display: swap
IBMPlexMono_Italic-s.p.... woff2 swap
Size 50 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexMono_Medium-s.p.... woff2 swap
Size 46 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexMono_MediumItali... woff2 swap
Size 51 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexMono_Regular-s.p... woff2 swap
Size 45 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexMono_SemiBold-s.... woff2 swap
Size 46 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
IBMPlexMono_SemiBoldIta... woff2 swap
Size 51 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
InterVariable-s.p.53d7b... woff2 swap
Size 345 KB
Load time 0 ms
Start 0 ms
Risk FOUT — 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
InterVariable_Italic-s.... woff2 swap
Size 380 KB
Load time 0 ms
Start 0 ms
Risk FOUT — 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
SourceSansPro_Regular_t... woff2 swap
Size 85 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Ubuntu_Mono_bold-s.p.36... woff2 swap
Size 79 KB
Load time 0 ms
Start 0 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)

Fixing the unchecked items could save ~362 KB and ~724 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+
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
96 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
11% of JavaScript execution is third-party
First-party Third-party 226ms · 0KB · $3/mo
Unattributable
Other
Costly
Execution 226ms
Transfer 0 KB
Monthly Cost $3/mo

These scripts may cost more than they're worth

  • Unattributable adds 226ms and costs ~$3/month

Unattributable takes 226ms 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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