Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

100

Accessibility

Best Practices

100

SEO

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

2.13 s

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

3.00 s

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

12 ms

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

0.089

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

2.63 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.

3.00 s

Page Load Progression

484 ms

969 ms

1.5 s

1.9 s

2.4 s

2.9 s

3.4 s

3.9 s

Checks

6 PASS 4 REVIEW 2 FIX

Third-Party Impact

Action

100% third-party, 0 ms blocking

FIX

100% third-party, 0 ms blocking

Third-party code accounts for 100% of page weight (869.5 KiB of 869.9 KiB)

Third-party blocking time is low (0 ms)

100%

First-party Third-party

HTTP Caching

Action

No cache headers

FIX

No cache headers

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.

Image Optimization

Action

23 images, 0 KB saveable

REVIEW

23 images, 0 KB saveable

https://www.service-public.gouv.fr/accueil/image is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

https://www.service-public.gouv.fr/resources/v-294... is missing width/height — may cause layout shift

Set explicit width and height to prevent CLS.

23 images 133 KB

0 oversized -0 KB

21 legacy format

2 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

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

JS Execution Cost

834ms total JS execution

REVIEW

834ms total JS execution

Unattributable: 213ms CPU time

https://www.service-public.gouv.fr/: 200ms CPU time

https://www.service-public.gouv.fr/resources/v-294...: 181ms CPU time

https://try.abtasty.com/f2a27ecc441fb1662a47bee9ea...: 95ms CPU time

https://www.service-public.gouv.fr/resources/v-294...: 77ms CPU time

Third-party scripts: 834ms (100% of total)

Main Thread Breakdown

Script Evaluation 39% Other 31% Style & Layout 17% Rendering 5% Parse HTML & CSS 4% Script Parsing & Compilation 3%

Script	Total	Scripting	Parse/Compile	Party
Unattributable	213ms	6ms	0ms	3rd
https://www.service-public.gouv.fr/	200ms	7ms	2ms	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/dsfr-1.14/dist/dsfr.module.min.js	181ms	93ms	0ms	3rd
https://try.abtasty.com/f2a27ecc441fb1662a47bee9ea97d2ea/main.bd148c84be49c96e30a2.js	95ms	53ms	6ms	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/dsfr-1.14/dist/analytics/analytics.module.min.js	77ms	74ms	0ms	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/common.js	67ms	46ms	9ms	3rd

JS Bundles

46 scripts, 76 KB unused

REVIEW

46 scripts, 76 KB unused

https://www.service-public.gouv.fr/resources/v-294...: 43 KB unused (65%)

Consider code splitting or tree shaking to reduce unused code.

https://www.service-public.gouv.fr/resources/v-294...: unminified — 12 KB could be saved

https://try.abtasty.com/f2a27ecc441fb1662a47bee9ea...: 33 KB unused (56%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 76 KB

76 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/common.js	66 KB	43 KB (65%)	✗	3rd
https://try.abtasty.com/f2a27ecc441fb1662a47bee9ea97d2ea/main.bd148c84be49c96e30a2.js	60 KB	33 KB (56%)	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/toolbar.js	1 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/dsfr-1.14/dist/analytics/analytics.module.min.js	17 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/require.js	7 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/dsfr-1.14/dist/dsfr.module.min.js	29 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/dsfr-1.14/js/configRgpdPart.js	4 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/coperia.js	1 KB	—	✓	3rd
https://try.abtasty.com/shared/commons.d69b79abf8e487019841.js	4 KB	—	✓	3rd
https://www.service-public.gouv.fr/resources/v-2940b6067e/assets/js/readspeaker/webReader.js?pids=wr&notools=1	25 KB	—	✓	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

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

Page Weight Budget

870 KB transferred, 93 requests

PASS

870 KB transferred, 93 requests

Page weighs 2.9 MB (870 KB transferred)

93 HTTP requests

Estimated 0.18 g CO2 per page load

870 KB transferred

93 requests

0.18 g CO2 per page load

JavaScript 309.7 KiB 36%

CSS 185.7 KiB 21%

Fonts 167.1 KiB 19%

Images 133.0 KiB 15%

Other 52.2 KiB 6%

HTML 12.5 KiB 1%

Other 8.2 KiB 1%

Other 912 B 0%

Other 678 B 0%

0 2.4 MB 4.9 MB

Under budget

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Font Loading

4 fonts (167 KB)

PASS

4 fonts (167 KB)

4 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

167 KB total

Render-blocking

of 4

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

Marianne-Regular.woff2 woff2 swap

Size 41 KB

Load time 0 ms

Start 0 ms

Risk FOUT — text flashes from fallback to web font

Marianne-Bold.woff2 woff2 swap

Size 41 KB

Load time 0 ms

Start 0 ms

Risk FOUT — text flashes from fallback to web font

Marianne-Medium.woff2 woff2 swap

Size 41 KB

Load time 0 ms

Start 0 ms

Risk FOUT — text flashes from fallback to web font

Marianne-Regular_Italic... woff2 swap

Size 44 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

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

Network Waterfall

93 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 834ms · 184KB · €9/mo

Script	Category	Execution	Transfer	Unused	Monthly Cost	Verdict
Unattributable Unattributable	Other	213ms	0 KB	—	€2/mo	Costly
www.service-public.gouv.fr www.service-public.gouv.fr	Other	200ms	12 KB	—	€2/mo	Costly
www.service-public.gouv.fr www.service-public.gouv.fr	Other	181ms	29 KB	—	€2/mo	Optional
try.abtasty.com try.abtasty.com	Other	95ms	60 KB	56%	€1/mo	Optional
www.service-public.gouv.fr www.service-public.gouv.fr	Other	77ms	17 KB	—	€1/mo	Optional
www.service-public.gouv.fr www.service-public.gouv.fr	Other	67ms	66 KB	65%	€1/mo	Optional

Unattributable

Other

Costly

Execution 213ms

Transfer 0 KB

Monthly Cost €2/mo

www.service-public.gouv.fr

Other

Costly

Execution 200ms

Transfer 12 KB

Monthly Cost €2/mo

www.service-public.gouv.fr

Other

Optional

Execution 181ms

Transfer 29 KB

Monthly Cost €2/mo

try.abtasty.com

Other

Optional

Execution 95ms

Transfer 60 KB

Unused 56%

Monthly Cost €1/mo

www.service-public.gouv.fr

Other

Optional

Execution 77ms

Transfer 17 KB

Monthly Cost €1/mo

www.service-public.gouv.fr

Other

Optional

Execution 67ms

Transfer 66 KB

Unused 65%

Monthly Cost €1/mo

These scripts may cost more than they're worth

Unattributable adds 213ms and costs ~€2/month
www.service-public.gouv.fr adds 200ms and costs ~€2/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

Unattributable takes 213ms 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

www.service-public.gouv.fr takes 200ms 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

56% of try.abtasty.com'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

65% of www.service-public.gouv.fr'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.