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.
1.07 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.13 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.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.82 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.
1.13 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 sDThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS BundlesAction44 scripts, 311 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://admin-pipeline.upsun-us-4.observability-pipeline.blackfire.io/js/probe.js | 97 KB | 88 KB (91%) | ✓ | 3rd |
| https://www.nrdc.org/themes/nrdc_theme/dist/js/common.js?tdnncw | 91 KB | 71 KB (78%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MX524FN | 189 KB | 65 KB (34%) | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202508.2.0/otBannerSdk.js | 121 KB | 64 KB (53%) | ✓ | 3rd |
| https://www.nrdc.org/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 | 32 KB | 24 KB (76%) | ✓ | 3rd |
| https://www.nrdc.org/core/misc/announce.js?v=10.5.9 | 2 KB | — | ✓ | 3rd |
| https://www.nrdc.org/core/misc/ajax.js?v=10.5.9 | 18 KB | — | ✗ | 3rd |
| https://try.abtasty.com/shared/commons.32b0810ba1fc402d09de.js | 4 KB | — | ✓ | 3rd |
| https://try.abtasty.com/4b1b0eeebfe9dd8b8b0c69f87f96647b/main.5e3a5918659353eff940.js | 46 KB | — | ✓ | 3rd |
| https://try.abtasty.com/shared/me.833a884d555fe9cd25c0.js | 3 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
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
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.2 MB transferred, 99 requestsREVIEW
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
BJS Execution Cost758ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.nrdc.org/ | 170ms | 10ms | 0ms | 3rd |
| Unattributable | 128ms | 23ms | 0ms | 3rd |
| https://www.nrdc.org/themes/nrdc_theme/dist/js/common.js?tdnncw | 119ms | 21ms | 5ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MX524FN | 110ms | 86ms | 14ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202508.2.0/otBannerSdk.js | 109ms | 67ms | 34ms | 3rd |
| https://try.abtasty.com/4b1b0eeebfe9dd8b8b0c69f87f96647b/main.5e3a5918659353eff940.js | 64ms | 55ms | 3ms | 3rd |
| https://www.nrdc.org/cdn-cgi/challenge-platform/scripts/jsd/main.js | 58ms | 56ms | 1ms | 3rd |
CPage Weight InventoryAction99 resources · 1.2 MB · 311 KB savings availableREVIEW
~311.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 99 resources | 1.2 MiB | ||||||
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
AImage Optimization8 images, 0 KB saveablePASS
A+Font Loading6 fonts (213 KB)PASS
Web fonts
6
213 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
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 CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall99 requests over 1817msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.nrdc.org www.nrdc.org | Other | 170ms | 25 KB | — | €2/mo | Optional |
Unattributable Unattributable | Other | 128ms | 0 KB | — | €1/mo | Optional |
www.nrdc.org www.nrdc.org | Other | 119ms | 91 KB | 78% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 110ms | 189 KB | 34% | €1/mo | Optional |
OneTrust cdn.cookielaw.org | Consent | 109ms | 121 KB | 53% | €1/mo | Essential |
try.abtasty.com try.abtasty.com | Other | 64ms | 46 KB | — | €1/mo | Optional |
www.nrdc.org www.nrdc.org | Other | 58ms | 0 KB | — | €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
78% of www.nrdc.org'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
53% of OneTrust'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