Performance
· 15 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
2.26 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
5.91 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
139 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.012
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.90 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.
7.57 s
Page Load Progression
392 ms 784 ms 1.2 s 1.6 s 2.0 s
2.4 s
2.7 s
3.1 sFPage Weight BudgetAction4.5 MB transferred, 127 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
Remove unused CSS rules with tools like PurgeCSS to reduce stylesheet size.
CSS bundle is large — purge unused styles (PurgeCSS, Tailwind JIT) to reduce CSS payload.
Source: web.dev
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS BundlesAction38 scripts, 631 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.washington.edu/static/home/wp-content/themes/uw-2014/js/site.js?ver=3.1 | 164 KB | 113 KB (69%) | ✓ | 3rd |
| https://www.washington.edu/static/home/wp-includes/js/jquery/jquery.js?9583878 | 279 KB | 95 KB (34%) | ✗ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-JLHM9WH4JV&cx=c>m=4e64f0 | 175 KB | 71 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-3T65WK0BM8&cx=c>m=4e64f0 | 157 KB | 65 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-KQ6QQBT | 169 KB | 60 KB (36%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=DC-4532109&cx=c>m=4e64f0 | 129 KB | 57 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-11078980387&cx=c>m=4e64f0 | 140 KB | 55 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16646132057&cx=c>m=4e64f0 | 148 KB | 51 KB (34%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 96 KB | 33 KB (35%) | ✓ | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 55 KB | 29 KB (53%) | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
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.
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.
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.
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.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
FPage Weight InventoryAction127 resources · 4.5 MB · 631 KB savings availableFIX
~631.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 127 resources | 4.5 MiB | ||||||
CImage OptimizationAction31 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
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.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
CJS Execution CostAction1467ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 223ms | 7ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-KQ6QQBT | 219ms | 190ms | 20ms | 3rd |
| https://www.washington.edu/ | 182ms | 3ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-JLHM9WH4JV&cx=c>m=4e64f0 | 112ms | 81ms | 18ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-16646132057&cx=c>m=4e64f0 | 106ms | 88ms | 16ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-3T65WK0BM8&cx=c>m=4e64f0 | 101ms | 77ms | 23ms | 3rd |
| https://script.crazyegg.com/pages/versioned/common-scripts/4ce8c7df8d425cc50464576824ed91eb.js | 88ms | 77ms | 6ms | 3rd |
| https://info.discoveruw.org/mtc.js | 85ms | 57ms | 1ms | 3rd |
| https://www.washington.edu/static/home/wp-includes/js/jquery/jquery.js?9583878 | 81ms | 50ms | 10ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-11078980387&cx=c>m=4e64f0 | 78ms | 64ms | 13ms | 3rd |
Showing top 10 of 13 scripts
BHTTP Cachingno-cacheREVIEW
no-cache
| Directive | Value | Meaning |
|---|---|---|
| no-cache | — | Cache but always revalidate first |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading7 fonts (248 KB)PASS
Web fonts
7
248 KB total
Render-blocking
0
of 7
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- 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 ~49 KB and ~98 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Google Cloud
Network Waterfall127 requests over 7853msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 223ms | 0 KB | — | $3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 219ms | 169 KB | 36% | $3/mo | Costly |
www.washington.edu www.washington.edu | Other | 182ms | 80 KB | — | $2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 112ms | 175 KB | 41% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 106ms | 148 KB | 34% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 101ms | 157 KB | 41% | $1/mo | Optional |
script.crazyegg.com script.crazyegg.com | Other | 88ms | 55 KB | 53% | $1/mo | Optional |
info.discoveruw.org info.discoveruw.org | Other | 85ms | 4 KB | — | $1/mo | Optional |
www.washington.edu www.washington.edu | Other | 81ms | 279 KB | 34% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 78ms | 140 KB | 40% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 73ms | 129 KB | 44% | $1/mo | Optional |
Microsoft Clarity scripts.clarity.ms | Session Replay | 68ms | 26 KB | — | $1/mo | Optional |
Facebook Pixel connect.facebook.net | Advertising | 51ms | 96 KB | 35% | $1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 223ms and costs ~$3/month
- Google Tag Manager adds 219ms and costs ~$3/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
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
Unattributable takes 223ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
Google Tag Manager takes 219ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
53% of script.crazyegg.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev