Skip to content
https://www.trello.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
75
GRADE
C
FIX
4
REVIEW
2
PASS
6
INFO
2

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

87
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
95
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.

1.29 s

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

1.29 s

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

88 ms

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

0.133

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

1.29 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.

2.57 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 s
Checks
14
6 PASS 2 REVIEW 4 FIX
D
Page Weight Budget
Action
2.1 MB transferred, 83 requests
FIX
2.1 MB transferred, 83 requests
Info::
Page weighs 7.1 MB (2.1 MB transferred)
Warning::
JavaScript is 1.3 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 1.3 MB
Info::
83 HTTP requests
Info::
Estimated 0.45 g CO2 per page load
2.1 MB / 2.4 MB budget
2.1 MB transferred
83 requests
0.45 g CO2 per page load
JavaScript 1.3 MiB 61%
Images 460.2 KiB 21%
Fonts 137.9 KiB 6%
Other 107.0 KiB 5%
HTML 97.9 KiB 4%
CSS 42.1 KiB 2%
Other 8.3 KiB 0%
Other 2.9 KiB 0%
Other 553 B 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Approaching limit

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

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 (2.1 MiB of 2.1 MiB)
Info::
Third-party blocking time is low (0 ms)
100%
First-party Third-party
F
JS Bundles
Action
49 scripts, 696 KB unused
FIX
49 scripts, 696 KB unused
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 179 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 179 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.gstatic.com/recaptcha/releases/kUYUkUl...: 179 KB unused (49%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-PJ8...: 86 KB unused (55%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://atl-global.atlassian.com/js/2.263.0/gasv3/...: 25 KB unused (67%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 696 KB
696 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js363 KB179 KB (49%)3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js0 KB179 KB (49%)3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js363 KB179 KB (49%)3rd
https://www.googletagmanager.com/gtm.js?id=GTM-PJ8M5SK158 KB86 KB (55%)3rd
https://atl-global.atlassian.com/js/2.263.0/gasv3/analytics-web-client.with-deps.amd.min.js37 KB25 KB (67%)3rd
https://atl-global.atlassian.com/js/2.263.0/atl-global-2.263.0.min.js10 KB23 KB (71%)3rd
https://atl-global.atlassian.com/js/2.263.0/atl-global-2.263.0.min.js0 KB23 KB (71%)3rd
https://bxp-content-static.prod.public.atl-paas.net/js/UiListCarousel.99ed7793f6d67ac442b5.min.js10 KB3rd
https://bxp-content-static.prod.public.atl-paas.net/js/UiCarousel.e92896bcafb0c3fc1ff0.min.js3 KB3rd
https://bxp-content-static.prod.public.atl-paas.net/js/UiNavLink.a7da7a9e7d78949e1fd0.min.js3 KB3rd

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.

C
JS Execution Cost
Action
1033ms total JS execution
REVIEW
1033ms total JS execution
Warning::
https://bxp-content-static.prod.public.atl-paas.ne...: 440ms CPU time
Info::
Unattributable: 156ms CPU time
Info::
https://bxp-content-static.prod.public.atl-paas.ne...: 147ms CPU time
Info::
https://trello.com/: 138ms CPU time
Info::
https://atl-global.atlassian.com/js/2.313.0/xid/at...: 89ms CPU time
Warning::
Third-party scripts: 1033ms (100% of total)

Main Thread Breakdown

Script Evaluation 59% Other 15% Style & Layout 12% Script Parsing & Compilation 7% Garbage Collection 3%
ScriptTotalScriptingParse/CompileParty
https://bxp-content-static.prod.public.atl-paas.net/js/vendors.b0b83a2116ee27958c23.min.js440ms407ms3ms3rd
Unattributable156ms7ms0ms3rd
https://bxp-content-static.prod.public.atl-paas.net/js/UiLink.51f0b5bca43d25c28aba.min.js147ms138ms0ms3rd
https://trello.com/138ms8ms0ms3rd
https://atl-global.atlassian.com/js/2.313.0/xid/atl-xid.js89ms0ms1ms3rd
https://www.gstatic.com/recaptcha/releases/kUYUkUlSyqkjTSMaN2w3RaOh/recaptcha__en.js63ms35ms25ms3rd
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

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+
Image Optimization
7 images, 0 KB saveable
PASS
7 images, 0 KB saveable
Info::
All images are well-optimized
7 images 460 KB
0 oversized -0 KB
1 legacy format
0 missing dimensions CLS risk
A+
Font Loading
5 fonts (138 KB)
PASS
5 fonts (138 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

138 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 FCP 1.3 s LCP 1.3 shttps://assets.ctfassets.net/rz1oowkt5gyp/41EruTPEOU9hcBwH94UVuZ/73ac40404d750278b451bf2adf186b1b/Charlie_Text-Regular.woff2Charlie_Text-Regular.woff2 https://assets.ctfassets.net/rz1oowkt5gyp/41EruTPEOU9hcBwH94UVuZ/73ac40404d750278b451bf2adf186b1b/Charlie_Text-Regular.woff2 — 25.3 KiB — 0 ms — font-display: swaphttps://assets.ctfassets.net/rz1oowkt5gyp/3KRSiun937K2pXBPYiUwgB/17f578e7699c12924de360e09c018c7c/Charlie_Display-Semibold.woff2Charlie_Display-Semibol... https://assets.ctfassets.net/rz1oowkt5gyp/3KRSiun937K2pXBPYiUwgB/17f578e7699c12924de360e09c018c7c/Charlie_Display-Semibold.woff2 — 26.0 KiB — 0 ms — font-display: swaphttps://assets.ctfassets.net/rz1oowkt5gyp/2d4nxzJwX8hfIqUN71D4OD/5e2c0c2a3677d935e91dd46635d5149d/Charlie_Text-Semibold.woff2Charlie_Text-Semibold.w... https://assets.ctfassets.net/rz1oowkt5gyp/2d4nxzJwX8hfIqUN71D4OD/5e2c0c2a3677d935e91dd46635d5149d/Charlie_Text-Semibold.woff2 — 25.6 KiB — 0 ms — font-display: swaphttps://assets.ctfassets.net/rz1oowkt5gyp/55uCHq9XzIzIG8yO7WRqfM/b62779fff17f06743e490f6d98a2001a/Charlie_Display-Bold.woff2Charlie_Display-Bold.woff2 https://assets.ctfassets.net/rz1oowkt5gyp/55uCHq9XzIzIG8yO7WRqfM/b62779fff17f06743e490f6d98a2001a/Charlie_Display-Bold.woff2 — 27.1 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 33.9 KiB — 0 ms — font-display: swap
Charlie_Text-Regular.woff2 woff2 swap
Size 25 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Charlie_Display-Semibol... woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Charlie_Text-Semibold.w... woff2 swap
Size 26 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Charlie_Display-Bold.woff2 woff2 swap
Size 27 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 34 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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 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
Network Waterfall
83 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 1033ms · 125KB · $14/mo
bxp-content-static.prod.public.atl-paas.net
Other
Costly
Execution 440ms
Transfer 44 KB
Monthly Cost $6/mo
Unattributable
Other
Optional
Execution 156ms
Transfer 0 KB
Monthly Cost $2/mo
bxp-content-static.prod.public.atl-paas.net
Other
Optional
Execution 147ms
Transfer 4 KB
Monthly Cost $2/mo
trello.com
Other
Optional
Execution 138ms
Transfer 64 KB
Monthly Cost $2/mo
atl-global.atlassian.com
Other
Optional
Execution 89ms
Transfer 14 KB
Monthly Cost $1/mo
www.gstatic.com
Other
Optional
Execution 63ms
Transfer 0 KB
Unused 49%
Monthly Cost $1/mo

These scripts may cost more than they're worth

  • bxp-content-static.prod.public.atl-paas.net adds 440ms and costs ~$6/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

bxp-content-static.prod.public.atl-paas.net takes 440ms 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

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.

Send Feedback