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.
724 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.77 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
389 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.
3.34 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.
7.63 s
Page Load Progression
FPage Weight BudgetAction15.7 MB transferred, 71 requestsFIX
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
FJS Execution CostAction5311ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://static.biosites.com/frontsitev2/_next/static/chunks/pages/index-02778307b67c7374.js | 3231ms | 522ms | 1ms | 3rd |
| https://biosites.com/ | 1282ms | 0ms | 0ms | 3rd |
| Unattributable | 352ms | 1ms | 0ms | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/pages/_app-697913021bf36662.js | 192ms | 68ms | 124ms | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/framework-e97e713fa51c2bbc.js | 144ms | 107ms | 4ms | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/754-c58fb2ee62b21c55.js | 55ms | 55ms | 0ms | 3rd |
| https://consent.trustarc.com/notice?domain=squarespace.com&c=teconsent&js=nj¬iceType=bb&text=true&pn=2>m=1&pcookie&language=en-us | 55ms | 51ms | 1ms | 3rd |
FJS BundlesAction14 scripts, 5.2 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://static.biosites.com/frontsitev2/_next/static/chunks/pages/_app-697913021bf36662.js | 7462 KB | 5016 KB (83%) | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/framework-e97e713fa51c2bbc.js | 186 KB | 74 KB (40%) | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/42-c2b91bb523df0bf8.js | 132 KB | 68 KB (54%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-K0M2DYJTG3 | 149 KB | 63 KB (42%) | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/449-685f808545518098.js | 117 KB | 62 KB (53%) | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/main-b4c65b66bbfb1da0.js | 134 KB | 53 KB (40%) | ✓ | 3rd |
| https://consent.trustarc.com/asset/notice.js/v/v1.7-1729 | 36 KB | 23 KB (63%) | ✓ | 3rd |
| https://consent.trustarc.com/notice?domain=squarespace.com&c=teconsent&js=nj¬iceType=bb&text=true&pn=2>m=1&pcookie&language=en-us | 13 KB | — | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/988-daf52607111f186c.js | 10 KB | — | ✓ | 3rd |
| https://static.biosites.com/frontsitev2/_next/static/chunks/754-c58fb2ee62b21c55.js | 16 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
FPage Weight InventoryAction71 resources · 15.7 MB · 5.2 MB savings availableFIX
~5.2 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 71 resources | 15.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
AImage Optimization21 images, 0 KB saveablePASS
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
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
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
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
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
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
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
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
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
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
A+Font Loading11 fonts (483 KB)PASS
Web fonts
11
483 KB total
Render-blocking
0
of 11
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
- 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 ~91 KB and ~182 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
Network Waterfall71 requests over 6417msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
static.biosites.com static.biosites.com | Other | 3231ms | 43 KB | — | €17/mo | Costly |
biosites.com biosites.com | Other | 1282ms | 14 KB | — | €7/mo | Costly |
Unattributable Unattributable | Other | 352ms | 0 KB | — | €2/mo | Costly |
static.biosites.com static.biosites.com | Other | 192ms | 7462 KB | 83% | €1/mo | Optional |
static.biosites.com static.biosites.com | Other | 144ms | 186 KB | 40% | €1/mo | Optional |
static.biosites.com static.biosites.com | Other | 55ms | 16 KB | — | €0/mo | Optional |
consent.trustarc.com consent.trustarc.com | Other | 55ms | 13 KB | — | €0/mo | Optional |
These scripts may cost more than they're worth
- static.biosites.com adds 3231ms and costs ~€17/month
- biosites.com adds 1282ms and costs ~€7/month
- Unattributable adds 352ms and costs ~€2/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
static.biosites.com takes 3231ms 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
biosites.com takes 1282ms 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
Unattributable takes 352ms 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
83% of static.biosites.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