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.
1.59 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.37 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
23 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.21 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.
3.37 s
Page Load Progression
FPage Weight BudgetAction2.8 MB transferred, 94 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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS BundlesAction34 scripts, 196 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-22a6ed7.js | 217 KB | 107 KB (49%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-D2YN8J64BE | 155 KB | 64 KB (41%) | ✓ | 3rd |
| https://www.colorado.gov/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 | 39 KB | 26 KB (67%) | ✓ | 3rd |
| https://www.colorado.gov/core/assets/vendor/loadjs/loadjs.min.js?v=4.3.0 | 2 KB | — | ✓ | 3rd |
| https://www.colorado.gov/core/misc/message.js?v=10.5.6 | 4 KB | — | ✗ | 3rd |
| https://www.colorado.gov/core/assets/vendor/once/once.min.js?v=1.0.1 | 2 KB | — | ✓ | 3rd |
| https://www.colorado.gov/core/misc/drupal.js?v=10.5.6 | 9 KB | — | ✗ | 3rd |
| https://www.colorado.gov/core/misc/drupal.init.js?v=10.5.6 | 1 KB | — | ✓ | 3rd |
| https://static.zdassets.com/ekr/snippet.js?key=7980b3ac-821f-4b97-9f91-7ba910c0d609 | 5 KB | — | ✓ | 3rd |
| https://www.colorado.gov/core/assets/vendor/tabbable/index.umd.min.js?v=6.2.0 | 4 KB | — | ✓ | 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
DPage Weight InventoryAction94 resources · 2.8 MB · 196 KB savings availableFIX
~196.1 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 94 resources | 2.8 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction5 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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+JS Execution Cost370ms total JS executionPASS
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.colorado.gov/ | 113ms | 5ms | 2ms | 3rd |
| Unattributable | 107ms | 6ms | 0ms | 3rd |
| https://static.zdassets.com/web_widget/messenger/latest/web-widget-main-22a6ed7.js | 93ms | 72ms | 20ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-D2YN8J64BE | 57ms | 47ms | 10ms | 3rd |
A+Font Loading19 fonts (594 KB)PASS
Web fonts
19
594 KB total
Render-blocking
0
of 19
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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 ~150 KB and ~300 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall94 requests over 3441msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.colorado.gov www.colorado.gov | Other | 113ms | 8 KB | — | $2/mo | Optional |
Unattributable Unattributable | Other | 107ms | 0 KB | — | $1/mo | Optional |
Zendesk Widget static.zdassets.com | Customer Support | 93ms | 217 KB | 49% | $1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 57ms | 155 KB | 41% | $1/mo | Optional |
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