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.
1.06 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.74 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
213 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.074
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.15 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.
10.45 s
Page Load Progression
1.3 s
2.6 s
3.9 s
5.2 s 6.5 s
7.8 s
9.1 s
10.4 sFPage Weight BudgetAction12.0 MB transferred, 225 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
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
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
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
DJS Execution CostAction3153ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.mimecast.com/ | 798ms | 16ms | 1ms | 3rd |
| Unattributable | 763ms | 24ms | 0ms | 3rd |
| https://fpjscdn.net/v3/9bsIAwFA2Yvt74r1OAYZ | 369ms | 288ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-M2787TN | 302ms | 248ms | 25ms | 3rd |
| https://unpkg.com/@lottiefiles/dotlottie-wc@0.9.12/dist/dist-ClwrCxoa.js | 192ms | 189ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-2RRJFGC554&cx=c>m=4e64k0h2 | 163ms | 125ms | 23ms | 3rd |
| https://cdn.optimizely.com/js/30177210136.js | 135ms | 112ms | 18ms | 3rd |
| https://www.mimecast.com/dist/site.ff160e92f68ef966136a.js | 121ms | 79ms | 36ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-987806786&cx=c>m=4e64k0h2 | 106ms | 83ms | 21ms | 3rd |
| https://j.6sc.co/6si.min.js | 73ms | 60ms | 2ms | 3rd |
Showing top 10 of 12 scripts
FJS BundlesAction51 scripts, 1.1 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.mimecast.com/dist/site.ff160e92f68ef966136a.js | 723 KB | 650 KB (90%) | ✓ | 3rd |
| https://rtp-static.marketo.com/rtp/libs/jqueryui/1.13.2/jquery-custom-ui.min.js | 126 KB | 106 KB (85%) | ✗ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202405.1.0/otBannerSdk.js | 109 KB | 68 KB (62%) | ✓ | 3rd |
| https://cdn.optimizely.com/js/30177210136.js | 145 KB | 64 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-2RRJFGC554&cx=c>m=4e64k0h2 | 170 KB | 64 KB (37%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-M2787TN | 187 KB | 62 KB (33%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-987806786&cx=c>m=4e64k0h2 | 144 KB | 56 KB (39%) | ✓ | 3rd |
| https://cdn.mouseflow.com/projects/e24f7e3a-5c9e-4ded-b913-3026146c2cf7.js | 53 KB | 40 KB (76%) | ✓ | 3rd |
| https://unpkg.com/@lottiefiles/dotlottie-wc@0.9.12/dist/dist-ClwrCxoa.js | 33 KB | 31 KB (95%) | ✓ | 3rd |
| https://lonrtp1-cdn.marketo.com/rtp-api/v1/rtp.js?aid=mimecast | 42 KB | 25 KB (61%) | ✓ | 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 InventoryAction225 resources · 12.0 MB · 1.1 MB savings availableFIX
~1.1 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 225 resources | 12.0 MiB | ||||||
CImage OptimizationAction104 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
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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading5 fonts (224 KB)PASS
Web fonts
5
224 KB total
Render-blocking
0
of 5
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
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 ~77 KB and ~154 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource HintsNo optimization neededPASS
AHTTP Cachingmax-age=10368000 (17 weeks)PASS
public, max-age=10368000
| Directive | Value | Meaning |
|---|---|---|
| public | — | Any cache may store this response |
| max-age | 10368000 | Cache for 17 weeks |
Network Waterfall225 requests over 10369msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.mimecast.com www.mimecast.com | Other | 798ms | 28 KB | — | £12/mo | Costly |
Unattributable Unattributable | Other | 763ms | 0 KB | — | £11/mo | Costly |
fpjscdn.net fpjscdn.net | Other | 369ms | 64 KB | — | £5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 302ms | 187 KB | 33% | £4/mo | Costly |
unpkg unpkg.com | CDN | 192ms | 33 KB | 95% | £3/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 163ms | 170 KB | 37% | £2/mo | Optional |
Optimizely cdn.optimizely.com | A/B Testing | 135ms | 145 KB | 44% | £2/mo | Optional |
www.mimecast.com www.mimecast.com | Other | 121ms | 723 KB | 90% | £2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 106ms | 144 KB | 39% | £2/mo | Optional |
j.6sc.co j.6sc.co | Other | 73ms | 19 KB | — | £1/mo | Optional |
Microsoft Clarity scripts.clarity.ms | Session Replay | 71ms | 26 KB | — | £1/mo | Optional |
lonrtp1-cdn.marketo.com lonrtp1-cdn.marketo.com | Other | 60ms | 42 KB | 61% | £1/mo | Optional |
These scripts may cost more than they're worth
- www.mimecast.com adds 798ms and costs ~£12/month
- Unattributable adds 763ms and costs ~£11/month
- fpjscdn.net adds 369ms and costs ~£5/month
- Google Tag Manager adds 302ms and costs ~£4/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
www.mimecast.com takes 798ms 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 763ms 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
fpjscdn.net takes 369ms 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 302ms 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
95% of unpkg'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
90% of www.mimecast.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
61% of lonrtp1-cdn.marketo.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