Performance
· 16 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.
6.63 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
31.67 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
4.87 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.487
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
25.01 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.
44.55 s
Page Load Progression
FPage Weight BudgetAction12.4 MB transferred, 520 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
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
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
FJS Execution CostAction39438ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://grind.co.uk/pages/en-us | 14360ms | 208ms | 58ms | 1st |
| Unattributable | 4599ms | 170ms | 0ms | 3rd |
| https://grind.co.uk/cdn/shop/t/207/assets/theme.js?v1.0.1&v=70234220758300410981775141279 | 3962ms | 3539ms | 29ms | 1st |
| https://grind.co.uk/cdn/shop/t/207/assets/vendor.js?v=30099029874421081791766411189 | 2358ms | 1570ms | 101ms | 1st |
| https://cdn.optimizely.com/js/25879780104.js | 1360ms | 787ms | 130ms | 3rd |
| https://grind.co.uk/cdn/wpm/b0e8c7c7aw41bd75a1p837d7fd4m8b145375m.js | 1353ms | 1012ms | 38ms | 1st |
| https://www.googletagmanager.com/gtm.js?id=GTM-MGRCJHV | 1067ms | 980ms | 58ms | 3rd |
| https://static.klaviyo.com/onsite/js/build-preview/commit-98747c9b1816a2f78e748cdc073a286a0296d9f7/1011.fa12d00c7a08724d2839.js | 1044ms | 819ms | 3ms | 3rd |
| https://scripts.clarity.ms/0.8.59/clarity.js | 952ms | 690ms | 9ms | 3rd |
| https://assets.gorgias.chat/build/static/js/279.6ba6eb825556cdb4.js | 652ms | 589ms | 31ms | 3rd |
Showing top 10 of 43 scripts
FJS BundlesAction246 scripts, 923 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=AW-794865512&cx=c>m=4e6461 | 143 KB | 105 KB (74%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-794865512&cx=c>m=4e6461 | 143 KB | 105 KB (74%) | ✓ | 3rd |
| https://grind.co.uk/cdn/shop/t/207/assets/wizard.js?v11775636009511 | 281 KB | 81 KB (29%) | ✓ | 1st |
| https://grind.co.uk/cdn/shop/t/207/assets/vendor.js?v=30099029874421081791766411189 | 82 KB | 57 KB (69%) | ✓ | 1st |
| https://grind.co.uk/cdn/shop/t/207/assets/vendor.js?v=30099029874421081791766411189 | 0 KB | 57 KB (69%) | ✓ | 1st |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMw.js | 110 KB | 57 KB (52%) | ✓ | 3rd |
| https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMw.js | 110 KB | 57 KB (52%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17893060665&cx=c>m=4e6461 | 143 KB | 56 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=AW-794865512&cx=c>m=4e6461 | 143 KB | 55 KB (38%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=AW-794865512&cx=c>m=4e6461 | 143 KB | 55 KB (38%) | ✓ | 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.
BThird-Party Impact59% third-party, 0 ms blockingREVIEW
CImage OptimizationAction94 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
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+Text CompressionAll text resources are compressedPASS
A+Font Loading21 fonts (217 KB)PASS
Web fonts
21
217 KB total
Render-blocking
0
of 21
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
- 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 ~48 KB and ~96 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints14 hints, 0 missing preconnectsPASS
Current Resource Hints
14 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall520 requests over 0msINFO
Performance analysis not available for this result.
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 4599ms | 0 KB | — | £24/mo | Costly |
Optimizely cdn.optimizely.com | A/B Testing | 1360ms | 0 KB | 46% | £7/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 1067ms | 166 KB | — | £6/mo | Costly |
static.klaviyo.com static.klaviyo.com | Other | 1044ms | 8 KB | — | £5/mo | Costly |
Microsoft Clarity scripts.clarity.ms | Session Replay | 952ms | 26 KB | — | £5/mo | Costly |
assets.gorgias.chat assets.gorgias.chat | Other | 652ms | 93 KB | 44% | £3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 575ms | 0 KB | — | £3/mo | Costly |
assets.gorgias.chat assets.gorgias.chat | Other | 464ms | 43 KB | — | £2/mo | Costly |
static.klaviyo.com static.klaviyo.com | Other | 442ms | 10 KB | — | £2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 418ms | 143 KB | 38% | £2/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 368ms | 40 KB | — | £2/mo | Costly |
analytics.tiktok.com analytics.tiktok.com | Other | 360ms | 110 KB | 52% | £2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 339ms | 143 KB | 39% | £2/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 278ms | 95 KB | 33% | £1/mo | Costly |
assets.gorgias.chat assets.gorgias.chat | Other | 242ms | 38 KB | — | £1/mo | Costly |
assets.gorgias.chat assets.gorgias.chat | Other | 237ms | 18 KB | — | £1/mo | Costly |
static.klaviyo.com static.klaviyo.com | Other | 164ms | 52 KB | 67% | £1/mo | Optional |
d.impactradius-event.com d.impactradius-event.com | Other | 147ms | 20 KB | — | £1/mo | Optional |
cdn.9gtb.com cdn.9gtb.com | Other | 146ms | 61 KB | 54% | £1/mo | Optional |
cdn.shopify.com cdn.shopify.com | Other | 136ms | 0 KB | — | £1/mo | Optional |
cdn.shopify.com cdn.shopify.com | Other | 126ms | 0 KB | — | £1/mo | Optional |
storage.googleapis.com storage.googleapis.com | Other | 106ms | 1 KB | — | £1/mo | Optional |
analytics.tiktok.com analytics.tiktok.com | Other | 94ms | 40 KB | — | £0/mo | Optional |
LinkedIn Insight snap.licdn.com | Advertising | 94ms | 19 KB | — | £0/mo | Optional |
widget.trustpilot.com widget.trustpilot.com | Other | 87ms | 8 KB | — | £0/mo | Optional |
static.klaviyo.com static.klaviyo.com | Other | 76ms | 0 KB | — | £0/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 68ms | 143 KB | 74% | £0/mo | Optional |
static.klaviyo.com static.klaviyo.com | Other | 68ms | 1 KB | — | £0/mo | Optional |
static.klaviyo.com static.klaviyo.com | Other | 56ms | 19 KB | — | £0/mo | Optional |
static-tracking.klaviyo.com static-tracking.klaviyo.com | Other | 55ms | 14 KB | — | £0/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 4599ms and costs ~£24/month
- Optimizely adds 1360ms and costs ~£7/month
- Google Tag Manager adds 1067ms and costs ~£6/month
- static.klaviyo.com adds 1044ms and costs ~£5/month
- Microsoft Clarity adds 952ms and costs ~£5/month
- assets.gorgias.chat adds 652ms and costs ~£3/month
- Google Tag Manager adds 575ms and costs ~£3/month
- assets.gorgias.chat adds 464ms and costs ~£2/month
- static.klaviyo.com adds 442ms and costs ~£2/month
- Google Tag Manager adds 418ms and costs ~£2/month
- Facebook Pixel adds 368ms and costs ~£2/month
- analytics.tiktok.com adds 360ms and costs ~£2/month
- Google Tag Manager adds 339ms and costs ~£2/month
- Facebook Pixel adds 278ms and costs ~£1/month
- assets.gorgias.chat adds 242ms and costs ~£1/month
- assets.gorgias.chat adds 237ms and costs ~£1/month
Unattributable takes 4599ms 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
Optimizely takes 1360ms 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 1067ms 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
static.klaviyo.com takes 1044ms 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
Microsoft Clarity takes 952ms 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
assets.gorgias.chat takes 652ms 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 575ms 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
assets.gorgias.chat takes 464ms 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
static.klaviyo.com takes 442ms 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 418ms 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
Facebook Pixel takes 368ms 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
analytics.tiktok.com takes 360ms 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
52% of analytics.tiktok.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
Google Tag Manager takes 339ms 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
Facebook Pixel takes 278ms 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
assets.gorgias.chat takes 242ms 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
assets.gorgias.chat takes 237ms 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
67% of static.klaviyo.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
54% of cdn.9gtb.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
74% of Google Tag Manager'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