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https://atlasobscura.com

Performance

· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
89
GRADE
B
FIX
3
REVIEW
0
PASS
12
INFO
2

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

Mobile Desktop
70
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
90
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.
40
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.

927 ms

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

2.91 s

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

1.27 s

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

0.006

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

927 ms

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

3.67 s

Page Load Progression

493 ms
986 ms
1.5 s
2.0 s
2.5 s
3.0 s
3.5 s
3.9 s
Checks
17
12 PASS 3 FIX
D
Third-Party Impact
Action
78% third-party, 0 ms blocking
FIX
78% third-party, 0 ms blocking
Warning::
Third-party code accounts for 78% of page weight (370.4 KiB of 472.7 KiB)
Info::
Third-party blocking time is low (0 ms)
22%
78%
First-party Third-party
D
JS Execution Cost
Action
2086ms total JS execution
FIX
2086ms total JS execution
Warning::
https://atlasobscura.com/cdn-cgi/challenge-platfor...: 1813ms CPU time
Info::
Unattributable: 169ms CPU time
Info::
https://atlasobscura.com/: 103ms CPU time
Info::
Third-party scripts: 169ms (8% of total)

Main Thread Breakdown

Script Evaluation 83% Other 10%
ScriptTotalScriptingParse/CompileParty
https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff16216ccd87991813ms1720ms32ms1st
Unattributable169ms9ms0ms3rd
https://atlasobscura.com/103ms14ms2ms1st
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.

A+
Page Weight Budget
473 KB transferred, 21 requests
PASS
473 KB transferred, 21 requests
Info::
Page weighs 888 KB (473 KB transferred)
Info::
21 HTTP requests
Info::
Estimated 0.10 g CO2 per page load
473 KB / 2.4 MB budget
473 KB transferred
21 requests
0.10 g CO2 per page load
Other 271.9 KiB 58%
HTML 97.6 KiB 21%
JavaScript 90.1 KiB 19%
Images 6.4 KiB 1%
Other 5.1 KiB 1%
Other 1.7 KiB 0%
0 2.4 MB 4.9 MB
Under budget
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
3 images, 0 KB saveable
PASS
3 images, 0 KB saveable
Info::
All images are well-optimized
3 images 6 KB
0 oversized -0 KB
3 legacy format
0 missing dimensions CLS risk
A+
Font Loading
No web fonts (system fonts)
PASS
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+
JS Bundles
10 scripts, 0 KB unused
PASS
10 scripts, 0 KB unused
0 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff16216ccd879973 KB—✓1st
blob:https://atlasobscura.com/0f0dde50-30b0-450e-bdc8-e45c99472dcd0 KB—✓3rd
https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit17 KB—✓3rd
blob:https://atlasobscura.com/8bb5cea2-a316-4c54-8a74-34cf47cae9a5-0 KB—✓3rd
blob:https://challenges.cloudflare.com/87967910-39f4-4b3e-b12e-1bdf28ee0e2b0 KB—✓3rd
blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58-0 KB—✓3rd
blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f580 KB—✓3rd
blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f580 KB—✓3rd
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
Page Weight Inventory
21 resources · 473 KB · 0 KB savings available
PASS
21 resources · 473 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 473 KB
Warning::
15 third-party resources (78% of weight)
Info::
1 resources over 200KB
21 resources · 472.7 KiB · 15 third-party Within 1MB page-weight target
Other 58% · 273.6 KiB
Document 22% · 102.6 KiB
JavaScript 19% · 90.1 KiB
Image 1% · 6.4 KiB
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
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
21 requests over 3292ms
INFO
0 ms 1.0 s 2.0 s 3.0 s FCP 927 ms LCP 2.9 shttps://atlasobscura.com// https://atlasobscura.com/ — 307 — 66 B — 23 ms — http/1.1https://atlasobscura.com// https://atlasobscura.com/ — 403 — 5.0 KiB — 9 ms — h3https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff16216ccd8799/cdn-cgi/challenge-platform/h/b/orc... https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9eff16216ccd8799 — 200 — 72.7 KiB — 22 ms — h3blob:https://atlasobscura.com/0f0dde50-30b0-450e-bdc8-e45c99472dcdatlasobscura.com/0f0dde50-30b0-450e... blob:https://atlasobscura.com/0f0dde50-30b0-450e-bdc8-e45c99472dcd — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicitchallenges.cloudflare.com/turnstile... https://challenges.cloudflare.com/turnstile/v0/b/0b8fb825cb67/api.js?onload=cFRiY3&render=explicit — 200 — 17.4 KiB — 20 ms — h3https://atlasobscura.com/favicon.ico/favicon.ico https://atlasobscura.com/favicon.ico — 403 — 5.9 KiB — 15 ms — h3https://atlasobscura.com/favicon.ico/favicon.ico https://atlasobscura.com/favicon.ico — 403 — 5.0 KiB — 13 ms — h3https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff16216ccd8799/ilgO5gLpREqfb5K1.jZcJYIGb._MefQQ..ROgiF8dfI-1776802795-1.2.1.1-PuvOJKBzay4WMXAPXLmaqoO.IGTmceIRwLdqUn4ShmHim6BBAbN2Yw0c9ti2WKMV/cdn-cgi/challenge-platform/h/b/flo... https://atlasobscura.com/cdn-cgi/challenge-platform/h/b/flow/ov1/2861708471:1776798608:ErqmkTBsxeuPEUEQ-nj3Qg5gifcpzcridMS7hc7f-HQ/9eff16216ccd8799/ilgO5gLpREqfb5K1.jZcJYIGb._MefQQ..ROgiF8dfI-1776802795-1.2.1.1-PuvOJKBzay4WMXAPXLmaqoO.IGTmceIRwLdqUn4ShmHim6BBAbN2Yw0c9ti2WKMV — 200 — 13.5 KiB — 25 ms — h3blob:https://atlasobscura.com/8bb5cea2-a316-4c54-8a74-34cf47cae9a5atlasobscura.com/8bb5cea2-a316-4c54... blob:https://atlasobscura.com/8bb5cea2-a316-4c54-8a74-34cf47cae9a5 — 200 — -1 B — 37 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/5rc1r/0x4AAAAAAADnPIDROrmt1Wwj/light/fbE/new/normal?lang=autochallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/turnstile/f/ov2/av0/rch/5rc1r/0x4AAAAAAADnPIDROrmt1Wwj/light/fbE/new/normal?lang=auto — 200 — 92.5 KiB — 32 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/cmg/1challenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/cmg/1 — 200 — 208 B — 5 ms — h3blob:https://challenges.cloudflare.com/87967910-39f4-4b3e-b12e-1bdf28ee0e2bchallenges.cloudflare.com/87967910-... blob:https://challenges.cloudflare.com/87967910-39f4-4b3e-b12e-1bdf28ee0e2b — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff1623be738746/k_vQO.6ldWRL23hMUB7zL0qQMlEAzZ0kb0BP9o3VKoo-1776802796-1.2.1.1-eo2SkV72OdHDSE1ykjXhCBBLC8AM893sqLEe2iMR63rftjRNxTid6Ec8SagBAEKJchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff1623be738746/k_vQO.6ldWRL23hMUB7zL0qQMlEAzZ0kb0BP9o3VKoo-1776802796-1.2.1.1-eo2SkV72OdHDSE1ykjXhCBBLC8AM893sqLEe2iMR63rftjRNxTid6Ec8SagBAEKJ — 200 — 258.4 KiB — 105 ms — h3blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58challenges.cloudflare.com/9819154e-... blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58 — 200 — -1 B — 20 ms — blobblob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58challenges.cloudflare.com/9819154e-... blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58 — 200 — -1 B — 43 ms — blobhttps://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff1623be738746/1776802796452/-48bUpbmzActVEhchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/d/9eff1623be738746/1776802796452/-48bUpbmzActVEh — 200 — 274 B — 6 ms — h3https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff1623be738746/1776802796452/f37f535136de7917a501a7ae986223ff1c506bcd9420cd63a79b4d9731f0a93f/Sy2UIMifSlNmRybchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/pat/9eff1623be738746/1776802796452/f37f535136de7917a501a7ae986223ff1c506bcd9420cd63a79b4d9731f0a93f/Sy2UIMifSlNmRyb — 401 — 1.7 KiB — 6 ms — h3blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58challenges.cloudflare.com/9819154e-... blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58 — 200 — -1 B — 23 ms — blobblob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58challenges.cloudflare.com/9819154e-... blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58 — -1 — 0 B — 0 ms — blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58challenges.cloudflare.com/9819154e-... blob:https://challenges.cloudflare.com/9819154e-e341-470e-aa27-1c31ba9c1f58 — -1 — 0 B — 0 ms — https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff1623be738746/k_vQO.6ldWRL23hMUB7zL0qQMlEAzZ0kb0BP9o3VKoo-1776802796-1.2.1.1-eo2SkV72OdHDSE1ykjXhCBBLC8AM893sqLEe2iMR63rftjRNxTid6Ec8SagBAEKJchallenges.cloudflare.com/cdn-cgi/c... https://challenges.cloudflare.com/cdn-cgi/challenge-platform/h/b/flow/ov1/1903685616:1776798609:2mBkH0c1QanQ_dZT3befYwdTaacqrcigMbTTBv3MVeo/9eff1623be738746/k_vQO.6ldWRL23hMUB7zL0qQMlEAzZ0kb0BP9o3VKoo-1776802796-1.2.1.1-eo2SkV72OdHDSE1ykjXhCBBLC8AM893sqLEe2iMR63rftjRNxTid6Ec8SagBAEKJ — -1 — 0 B — 0 ms —
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
8% of JavaScript execution is third-party
First-party Third-party 169ms · 0KB · $2/mo
Unattributable
Other
Optional
Execution 169ms
Transfer 0 KB
Monthly Cost $2/mo

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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