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https://www.glossier.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
65
GRADE
D
FIX
5
REVIEW
1
PASS
6
INFO
2

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

Mobile Desktop
57
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
85
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
81
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
100
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.

680 ms

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

1.37 s

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

589 ms

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

0.184

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

2.59 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.

8.38 s

Page Load Progression

2.7 s
5.3 s
8.0 s
10.7 s
13.3 s
16.0 s
18.7 s
21.3 s
Checks
14
6 PASS 1 REVIEW 5 FIX
F
Page Weight Budget
Action
15.9 MB transferred, 426 requests
FIX
15.9 MB transferred, 426 requests
Critical::
Page weighs 25.0 MB (15.9 MB transferred)
Warning::
JavaScript is 3.7 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 3.7 MB
Warning::
426 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 3.3 g CO2 per page load
15.9 MB / 2.4 MB budget
15.9 MB transferred
426 requests
3.3 g CO2 per page load
Other 9.7 MiB 61%
JavaScript 3.7 MiB 23%
Other 1.2 MiB 8%
Images 651.7 KiB 4%
HTML 255.6 KiB 2%
Fonts 152.1 KiB 1%
Other 118.8 KiB 1%
Other 80.2 KiB 0%
CSS 49.1 KiB 0%
Other 22.1 KiB 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
89% third-party, 0 ms blocking
FIX
89% third-party, 0 ms blocking
Warning::
Third-party code accounts for 89% of page weight (14.1 MiB of 15.9 MiB)
Info::
Third-party blocking time is low (0 ms)
89%
First-party Third-party
F
JS Execution Cost
Action
7396ms total JS execution
FIX
7396ms total JS execution
Warning::
https://www.glossier.com/cdn/wpm/bcfa8229ew36b6053...: 1044ms CPU time
Warning::
Unattributable: 995ms CPU time
Warning::
https://www.glossier.com/: 930ms CPU time
Warning::
https://www.glossier.com/cdn/shop/t/1393/assets/ap...: 703ms CPU time
Warning::
https://edge.fullstory.com/s/fs.js: 599ms CPU time
Warning::
Third-party scripts: 4412ms (60% of total)

Main Thread Breakdown

Script Evaluation 59% Other 21% Style & Layout 11% Script Parsing & Compilation 4%
ScriptTotalScriptingParse/CompileParty
https://www.glossier.com/cdn/wpm/bcfa8229ew36b6053dp1e134caame9d83f21m.js1044ms710ms6ms1st
Unattributable995ms156ms0ms3rd
https://www.glossier.com/930ms117ms8ms1st
https://www.glossier.com/cdn/shop/t/1393/assets/app.min.js?v=116494217122873023101774881013703ms278ms17ms1st
https://edge.fullstory.com/s/fs.js599ms439ms8ms3rd
https://cdn.optimizely.com/js/22916101539.js483ms353ms10ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-KW9HP9Z295ms270ms16ms3rd
https://21bd15724800.cdn4.forter.com/sn/21bd15724800/script.js282ms253ms19ms3rd
https://onsite.joinground.com/ground.js259ms241ms9ms3rd
https://7ce243a1e1a2.cdn4.forter.com/sn/7ce243a1e1a2/script.js219ms197ms13ms3rd

Showing top 10 of 26 scripts

F
JS Bundles
Action
217 scripts, 1.3 MB unused
FIX
217 scripts, 1.3 MB unused
Warning::
https://7ce243a1e1a2.cdn4.forter.com/sn/7ce243a1e1...: 93 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://21bd15724800.cdn4.forter.com/sn/21bd157248...: 89 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://21bd15724800.cdn4.forter.com/sn/21bd157248...: 89 KB unused (42%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://static.rechargecdn.com/assets/js/widget.mi...: 75 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/js?id=G-J11M...: 67 KB unused (40%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.3 MB
1288 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://7ce243a1e1a2.cdn4.forter.com/sn/7ce243a1e1a2/script.js221 KB93 KB (42%)✓3rd
https://21bd15724800.cdn4.forter.com/sn/21bd15724800/script.js213 KB89 KB (42%)✓3rd
https://21bd15724800.cdn4.forter.com/sn/21bd15724800/script.js213 KB89 KB (42%)✓3rd
https://static.rechargecdn.com/assets/js/widget.min.js?shop=glossier-admin.myshopify.com119 KB75 KB (63%)✓3rd
https://www.googletagmanager.com/gtag/js?id=G-J11MBLGD5V&cx=c&gtm=4e6411168 KB67 KB (40%)✓3rd
https://cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js128 KB66 KB (51%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=MC-CKB65RMMGX&cx=c&gtm=4e6411135 KB64 KB (48%)✓3rd
https://www.googletagmanager.com/gtag/js?id=GT-TBW8XFPT135 KB59 KB (44%)✓3rd
https://analytics.tiktok.com/i18n/pixel/static/main.MWE0ZWQ3ZWQwMw.js110 KB59 KB (54%)✓3rd
https://static.clairedefermat.com/pixel/v2/pixel.js70 KB58 KB (84%)✓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.
Info::
ETag present — enables conditional (304) responses

No Cache-Control header

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

C
Image Optimization
Action
26 images, 0 KB saveable
REVIEW
26 images, 0 KB saveable
Warning::
is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://glossier-prod.imgix.net/files/glossier-soi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://glossier-prod.imgix.net/files/glossier-soi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.glossier.com/cdn/shop/t/1393/assets/se... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://glossier-prod.imgix.net/files/glossier-soi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://glossier-prod.imgix.net/files/glossier-soi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
26 images 652 KB
0 oversized -0 KB
15 legacy format
6 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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

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
11 fonts (185 KB)
PASS
11 fonts (185 KB)
Info::
11 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

11

185 KB total

Render-blocking

0

of 11

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 680 ms LCP 1.4 shttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu.woff?v=27749520405110232131774881013Apercu.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu.woff?v=27749520405110232131774881013 — 16.7 KiB — 0 ms — font-display: swaphttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu-MediumItalic.woff?v=166049247236756587401774881013Apercu-MediumItalic.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu-MediumItalic.woff?v=166049247236756587401774881013 — 18.0 KiB — 0 ms — font-display: swaphttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Bold.woff?v=77441056927343755651774881013Apercu-Bold.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Bold.woff?v=77441056927343755651774881013 — 16.5 KiB — 0 ms — font-display: swaphttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Medium.woff?v=135256279722417433531774881013Apercu-Medium.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Medium.woff?v=135256279722417433531774881013 — 16.8 KiB — 0 ms — font-display: swaphttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Mono.woff?v=95926578357820724491774881013Apercu-Mono.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Mono.woff?v=95926578357820724491774881013 — 11.7 KiB — 0 ms — font-display: swaphttps://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Italic.woff?v=167501330633256636311774881013Apercu-Italic.woff https://www.glossier.com/cdn/shop/t/1393/assets/Apercu-Italic.woff?v=167501330633256636311774881013 — 18.3 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-regular.woff2?v=1652966868font-apercupro-regular.... https://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-regular.woff2?v=1652966868 — 17.7 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-medium.woff2?v=1679586878font-apercupro-medium.w... https://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-medium.woff2?v=1679586878 — 18.2 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-medium.woff?v=1679586878font-apercupro-medium.woff https://cdn.shopify.com/s/files/1/0627/9164/7477/files/font-apercupro-medium.woff?v=1679586878 — 18.2 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0627/9164/7477/files/Apercu.woff2?v=1721062709Apercu.woff2 https://cdn.shopify.com/s/files/1/0627/9164/7477/files/Apercu.woff2?v=1721062709 — 16.6 KiB — 0 ms — font-display: swaphttps://cdn.shopify.com/s/files/1/0627/9164/7477/files/Apercu-Bold.woff2?v=1721062709Apercu-Bold.woff2 https://cdn.shopify.com/s/files/1/0627/9164/7477/files/Apercu-Bold.woff2?v=1721062709 — 16.4 KiB — 0 ms — font-display: swap
Apercu.woff woff swap
Size 17 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
Apercu-MediumItalic.woff woff swap
Size 18 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
Apercu-Bold.woff woff swap
Size 16 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
Apercu-Medium.woff woff swap
Size 17 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
Apercu-Mono.woff woff swap
Size 12 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
Apercu-Italic.woff woff swap
Size 18 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
font-apercupro-regular.... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font-apercupro-medium.w... woff2 swap
Size 18 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
font-apercupro-medium.woff woff swap
Size 18 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
Apercu.woff2 woff2 swap
Size 17 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
Apercu-Bold.woff2 woff2 swap
Size 16 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)

Fixing the unchecked items could save ~35 KB and ~70 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
426 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
60% of JavaScript execution is third-party
First-party Third-party 4412ms · 2077KB · €23/mo
Unattributable
Other
Costly
Execution 995ms
Transfer 0 KB
Monthly Cost €5/mo
edge.fullstory.com
Other
Costly
Execution 599ms
Transfer 80 KB
Unused 32%
Monthly Cost €3/mo
Optimizely
A/B Testing
Costly
Execution 483ms
Transfer 105 KB
Unused 30%
Monthly Cost €3/mo
Google Tag Manager
Tag Manager
Costly
Execution 295ms
Transfer 172 KB
Unused 31%
Monthly Cost €2/mo
21bd15724800.cdn4.forter.com
Other
Costly
Execution 282ms
Transfer 213 KB
Unused 42%
Monthly Cost €1/mo
onsite.joinground.com
Other
Costly
Execution 259ms
Transfer 64 KB
Monthly Cost €1/mo
7ce243a1e1a2.cdn4.forter.com
Other
Costly
Execution 219ms
Transfer 221 KB
Unused 42%
Monthly Cost €1/mo
(program):2
Other
Optional
Execution 166ms
Transfer 0 KB
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 158ms
Transfer 135 KB
Unused 44%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 140ms
Transfer 143 KB
Unused 36%
Monthly Cost €1/mo
Google Tag Manager
Tag Manager
Optional
Execution 115ms
Transfer 168 KB
Unused 40%
Monthly Cost €1/mo
assets.gorgias.chat
Other
Optional
Execution 94ms
Transfer 93 KB
Unused 49%
Monthly Cost €0/mo
us-assets.i.posthog.com
Other
Optional
Execution 90ms
Transfer 65 KB
Unused 51%
Monthly Cost €0/mo
OneTrust
Consent
Essential
Execution 87ms
Transfer 128 KB
Unused 51%
Monthly Cost €0/mo
analytics.tiktok.com
Other
Optional
Execution 83ms
Transfer 110 KB
Unused 54%
Monthly Cost €0/mo
static.rechargecdn.com
Other
Optional
Execution 74ms
Transfer 119 KB
Unused 63%
Monthly Cost €0/mo
Google Tag Manager
Tag Manager
Optional
Execution 73ms
Transfer 135 KB
Unused 48%
Monthly Cost €0/mo
Facebook Pixel
Advertising
Optional
Execution 68ms
Transfer 95 KB
Unused 38%
Monthly Cost €0/mo
static.klaviyo.com
Other
Optional
Execution 66ms
Transfer 23 KB
Monthly Cost €0/mo
static.klaviyo.com
Other
Optional
Execution 66ms
Transfer 8 KB
Monthly Cost €0/mo

These scripts may cost more than they're worth

  • Unattributable adds 995ms and costs ~€5/month
  • edge.fullstory.com adds 599ms and costs ~€3/month
  • Optimizely adds 483ms and costs ~€3/month
  • Google Tag Manager adds 295ms and costs ~€2/month
  • 21bd15724800.cdn4.forter.com adds 282ms and costs ~€1/month
  • onsite.joinground.com adds 259ms and costs ~€1/month
  • 7ce243a1e1a2.cdn4.forter.com adds 219ms and costs ~€1/month

60% of JavaScript execution time comes from third-party scripts.

Why this matters

Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.

Learn more ▾

Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.

Source: web.dev / HTTP Archive Web Almanac

Unattributable takes 995ms 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

edge.fullstory.com takes 599ms 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

Optimizely takes 483ms 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

Google Tag Manager takes 295ms 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

21bd15724800.cdn4.forter.com takes 282ms 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

onsite.joinground.com takes 259ms 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

7ce243a1e1a2.cdn4.forter.com takes 219ms 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

51% of us-assets.i.posthog.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

51% of OneTrust'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

54% of analytics.tiktok.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

63% of static.rechargecdn.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

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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