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Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
72
GRADE
C
FIX
5
REVIEW
1
PASS
6
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
80
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
80
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
96
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
85
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

886 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.45 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

193 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.091

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

2.73 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.

4.56 s

Page Load Progression

1.2 s
2.3 s
3.5 s
4.6 s
5.8 s
6.9 s
8.1 s
9.3 s
Checks
14
6 PASS 1 REVIEW 5 FIX
F
Page Weight Budget
Action
3.8 MB transferred, 209 requests
FIX
3.8 MB transferred, 209 requests
Warning::
Page weighs 11.5 MB (3.8 MB transferred)
Warning::
JavaScript is 2.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 2.1 MB
Warning::
209 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 0.79 g CO2 per page load
3.8 MB / 2.4 MB budget
3.8 MB transferred
209 requests
0.79 g CO2 per page load
JavaScript 2.1 MiB 55%
Other 1.0 MiB 27%
HTML 221.2 KiB 6%
Images 194.3 KiB 5%
Fonts 152.0 KiB 4%
CSS 108.9 KiB 3%
Other 46.6 KiB 1%
Other 186 B 0%
Other 0 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
100% third-party, 0 ms blocking
FIX
100% third-party, 0 ms blocking
Warning::
Third-party code accounts for 100% of page weight (3.8 MiB of 3.8 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Execution Cost
Action
10722ms total JS execution
FIX
10722ms total JS execution
Warning::
https://redis.io/_next/static/chunks/7369-0f075421...: 7676ms CPU time
Warning::
https://redis.io/: 1155ms CPU time
Warning::
Unattributable: 1087ms CPU time
Info::
https://cdn.amplitude.com/engagement-browser/prod/...: 199ms CPU time
Info::
https://redis.io/_next/static/chunks/9146-646ea785...: 122ms CPU time
Warning::
Third-party scripts: 10722ms (100% of total)

Main Thread Breakdown

Other 49% Script Evaluation 24% Style & Layout 13% Rendering 11%
ScriptTotalScriptingParse/CompileParty
https://redis.io/_next/static/chunks/7369-0f0754218170d7e9.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw7676ms1705ms10ms3rd
https://redis.io/1155ms29ms32ms3rd
Unattributable1087ms79ms0ms3rd
https://cdn.amplitude.com/engagement-browser/prod/split/index.js199ms188ms0ms3rd
https://redis.io/_next/static/chunks/9146-646ea7851ff0b9e9.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw122ms100ms19ms3rd
https://redis.io/_next/static/chunks/bf76e631-a760aa8cff633f5a.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw101ms97ms3ms3rd
https://redis.io/_next/static/chunks/bf6a786c-381ced19b77084c2.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw98ms84ms3ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TKZ6J9R88ms66ms16ms3rd
https://consent.trustarc.com/asset/notice.js/v/v1.7-854976ms48ms3ms3rd
https://redis.io/_next/static/chunks/2636-1969dde127208522.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw61ms51ms11ms3rd

Showing top 10 of 11 scripts

F
JS Bundles
Action
48 scripts, 1.1 MB unused
FIX
48 scripts, 1.1 MB unused
Warning::
https://redis.io/_next/static/chunks/c36f3faa-bf84...: 342 KB unused (80%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://redis.io/_next/static/chunks/9146-646ea785...: 213 KB unused (76%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://redis.io/_next/static/chunks/1453-51dbae4c...: 128 KB unused (72%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://cdn.amplitude.com/engagement-browser/prod/...: 98 KB unused (58%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://redis.io/_next/static/chunks/2170a4aa-1514...: 88 KB unused (81%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.1 MB
1155 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://redis.io/_next/static/chunks/c36f3faa-bf8431af233775b3.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw427 KB342 KB (80%)✓3rd
https://redis.io/_next/static/chunks/9146-646ea7851ff0b9e9.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw282 KB213 KB (76%)✓3rd
https://redis.io/_next/static/chunks/1453-51dbae4c2474dde3.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw177 KB128 KB (72%)✓3rd
https://cdn.amplitude.com/engagement-browser/prod/split/df9b61a9061fbc33ed8e6b620d00ea2d64efb94f-chunk-7V35RKKP.js168 KB98 KB (58%)✓3rd
https://redis.io/_next/static/chunks/2170a4aa-1514f5a56eef99b1.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw110 KB88 KB (81%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-TKZ6J9R174 KB81 KB (47%)✓3rd
https://redis.io/_next/static/chunks/2636-1969dde127208522.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw136 KB81 KB (59%)✓3rd
https://redis.io/_next/static/chunks/7369-0f0754218170d7e9.js?dpl=dpl_em4Txm4spqw9TmwDRzvoK8nocXcw109 KB52 KB (48%)✓3rd
https://cdn.amplitude.com/engagement-browser/prod/split/df9b61a9061fbc33ed8e6b620d00ea2d64efb94f-chunk-WO7XXSIO.js65 KB48 KB (75%)✓3rd
https://cdn.amplitude.com/engagement-browser/prod/split/index.js40 KB23 KB (58%)✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

F
HTTP Caching
Action
No cache headers
FIX
No cache headers
Warning::
No Cache-Control header found
Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.

No Cache-Control header

Adding a Cache-Control header can significantly improve repeat-visit performance.

B
Image Optimization
93 images, 0 KB saveable
REVIEW
93 images, 0 KB saveable
Warning::
https://cdn.sanity.io/images/sy1jschh/production/8... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
93 images 194 KB
0 oversized -0 KB
48 legacy format
1 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
5 fonts (152 KB)
PASS
5 fonts (152 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

152 KB total

Render-blocking

0

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s 1.5 s FCP 886 ms LCP 1.4 shttps://redis.io/_next/static/media/36966cca54120369-s.p.woff236966cca54120369-s.p.woff2 https://redis.io/_next/static/media/36966cca54120369-s.p.woff2 — 22.0 KiB — 0 ms — font-display: swaphttps://redis.io/_next/static/media/489d530265462d6c-s.p.woff2489d530265462d6c-s.p.woff2 https://redis.io/_next/static/media/489d530265462d6c-s.p.woff2 — 64.5 KiB — 0 ms — font-display: swaphttps://redis.io/_next/static/media/806de4d605d3ad01-s.p.woff2806de4d605d3ad01-s.p.woff2 https://redis.io/_next/static/media/806de4d605d3ad01-s.p.woff2 — 9.5 KiB — 0 ms — font-display: swaphttps://redis.io/_next/static/media/fc727f226c737876-s.p.woff2fc727f226c737876-s.p.woff2 https://redis.io/_next/static/media/fc727f226c737876-s.p.woff2 — 9.5 KiB — 0 ms — font-display: swaphttps://consent.trustarc.com/get?name=Graphik-Regular.ttfget https://consent.trustarc.com/get?name=Graphik-Regular.ttf — 46.5 KiB — 0 ms — font-display: swap
36966cca54120369-s.p.woff2 woff2 swap
Size 22 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
489d530265462d6c-s.p.woff2 woff2 swap
Size 64 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
806de4d605d3ad01-s.p.woff2 woff2 swap
Size 10 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
fc727f226c737876-s.p.woff2 woff2 swap
Size 10 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
get ttf swap
Size 46 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
  • 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 ~14 KB and ~28 ms

A+
Resource Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Network Waterfall
209 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100% of JavaScript execution is third-party
First-party Third-party 10722ms · 1103KB · $201/mo
redis.io
Other
Costly
Execution 7676ms
Transfer 109 KB
Unused 48%
Monthly Cost $144/mo
redis.io
Other
Costly
Execution 1155ms
Transfer 221 KB
Monthly Cost $22/mo
Unattributable
Other
Costly
Execution 1087ms
Transfer 0 KB
Monthly Cost $20/mo
Amplitude
Analytics
Optional
Execution 199ms
Transfer 40 KB
Unused 58%
Monthly Cost $4/mo
redis.io
Other
Optional
Execution 122ms
Transfer 282 KB
Unused 76%
Monthly Cost $2/mo
redis.io
Other
Optional
Execution 101ms
Transfer 39 KB
Monthly Cost $2/mo
redis.io
Other
Optional
Execution 98ms
Transfer 55 KB
Monthly Cost $2/mo
Google Tag Manager
Tag Manager
Optional
Execution 88ms
Transfer 174 KB
Unused 47%
Monthly Cost $2/mo
consent.trustarc.com
Other
Optional
Execution 76ms
Transfer 36 KB
Monthly Cost $1/mo
redis.io
Other
Optional
Execution 61ms
Transfer 136 KB
Unused 59%
Monthly Cost $1/mo
jsDelivr
CDN
Optional
Execution 58ms
Transfer 10 KB
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • redis.io adds 7676ms and costs ~$144/month
  • redis.io adds 1155ms and costs ~$22/month
  • Unattributable adds 1087ms and costs ~$20/month

100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.

Why this matters

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

redis.io takes 7676ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

redis.io takes 1155ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Unattributable takes 1087ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

58% of Amplitude's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

76% of redis.io's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

59% of redis.io's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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