https://osmfoundation.org
Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
95
GRADE
A
FIX
0
REVIEW
5
PASS
10
INFO
2
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
100
95
96
91
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
954 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.03 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
35 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.38 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.
2.00 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 sChecks
1710 PASS 5 REVIEW
BImage Optimization8 images, 0 KB saveableREVIEW
Image Optimization
8 images, 0 KB saveable
8 images, 0 KB saveable
Info::
All images are well-optimized
8 images 2 KB
0 oversized -0 KB
7 legacy format
0 missing dimensions CLS risk
BJS Execution Cost833ms total JS executionREVIEW
JS Execution Cost
833ms total JS execution
833ms total JS execution
Warning::
https://osmfoundation.org/: 260ms CPU time
Info::
Unattributable: 232ms CPU time
Info::
https://osmfoundation.org/w/load.php?lang=en&modul...: 208ms CPU time
Info::
https://osmfoundation.org/w/load.php?lang=en&modul...: 133ms CPU time
Info::
Third-party scripts: 232ms (28% of total)
Main Thread Breakdown
Script Evaluation 37% Other 29% Style & Layout 19% Script Parsing & Compilation 9% Rendering 3%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://osmfoundation.org/ | 260ms | 12ms | 5ms | 1st |
| Unattributable | 232ms | 8ms | 0ms | 3rd |
| https://osmfoundation.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=minerva | 208ms | 168ms | 5ms | 1st |
| https://osmfoundation.org/w/load.php?lang=en&modules=ext.checkUser.clientHints%7Cjquery%2Coojs%2Csite%7Cjquery.client%7Cmediawiki.String%2CTitle%2CUri%2Capi%2Cbase%2Ccldr%2Ccookie%2Cexperiments%2CjqueryMsg%2Clanguage%2Crouter%2Cstorage%2Ctemplate%2Cuser%2Cutil%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.ready%7Cmediawiki.page.watch.ajax%7Cmediawiki.template.mustache%7Cmobile.codex.styles%7Cmobile.init%2Cstartup%7Cmobile.pagelist.styles%7Cmobile.pagesummary.styles%7Cskins.minerva.messageBox.styles%7Cskins.minerva.scripts&skin=minerva&version=156d8 | 133ms | 48ms | 80ms | 1st |
BJS Bundles2 scripts, 53 KB unusedREVIEW
JS Bundles
2 scripts, 53 KB unused
2 scripts, 53 KB unused
Warning::
https://osmfoundation.org/w/load.php?lang=en&modul...: 53 KB unused (41%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 53 KB
53 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://osmfoundation.org/w/load.php?lang=en&modules=ext.checkUser.clientHints%7Cjquery%2Coojs%2Csite%7Cjquery.client%7Cmediawiki.String%2CTitle%2CUri%2Capi%2Cbase%2Ccldr%2Ccookie%2Cexperiments%2CjqueryMsg%2Clanguage%2Crouter%2Cstorage%2Ctemplate%2Cuser%2Cutil%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.ready%7Cmediawiki.page.watch.ajax%7Cmediawiki.template.mustache%7Cmobile.codex.styles%7Cmobile.init%2Cstartup%7Cmobile.pagelist.styles%7Cmobile.pagesummary.styles%7Cskins.minerva.messageBox.styles%7Cskins.minerva.scripts&skin=minerva&version=156d8 | 129 KB | 53 KB (41%) | ✓ | 1st |
| https://osmfoundation.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=minerva | 12 KB | — | ✓ | 1st |
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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
BHTTP Cachingprivate, must-revalidate, max-age=0REVIEW
HTTP Caching
private, must-revalidate, max-age=0
private, must-revalidate, max-age=0
Info::
Cache-Control header is set
Got: private, must-revalidate, max-age=0
Info::
Last-Modified header present
Cache-Control
private, must-revalidate, max-age=0
| Directive | Value | Meaning |
|---|---|---|
| private | — | Only browser cache, not CDN/proxy |
| must-revalidate | — | Must recheck with server after expiry |
| max-age | 0 | Cache for 0 seconds |
A+Page Weight Budget178 KB transferred, 18 requestsPASS
Page Weight Budget
178 KB transferred, 18 requests
178 KB transferred, 18 requests
Info::
Page weighs 801 KB (178 KB transferred)
Info::
18 HTTP requests
Info::
Estimated 0.04 g CO2 per page load
178 KB transferred
18 requests
0.04 g CO2 per page load
JavaScript 140.7 KiB 79%
CSS 14.3 KiB 8%
Other 13.8 KiB 8%
HTML 6.7 KiB 4%
Images 2.1 KiB 1%
Other 436 B 0%
0 2.4 MB 4.9 MB
Under budget
A+Third-Party ImpactNo third-party resourcesPASS
Third-Party Impact
No third-party resources
No third-party resources
Info::
No third-party resources detected
No third-party resources detected — all resources are first-party.
A+Text CompressionAll text resources are compressedPASS
Text Compression
All text resources are compressed
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+Font LoadingNo web fonts (system fonts)PASS
Font Loading
No web fonts (system fonts)
No web fonts (system fonts)
Info::
No web fonts loaded — system fonts are fastest
No web fonts loaded — system fonts are optimal.
A+Resource CachingAll resources properly cachedPASS
Resource Caching
All resources properly cached
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+Critical Rendering PathNo render-blocking resourcesPASS
Critical Rendering Path
No render-blocking resources
No render-blocking resources
Info::
No render-blocking resources detected
A+Resource HintsNo optimization neededPASS
Resource Hints
No optimization needed
No optimization needed
Info::
No resource hint issues
A+Page Weight Inventory18 resources · 178 KB · 53 KB savings availablePASS
Page Weight Inventory
18 resources · 178 KB · 53 KB savings available
18 resources · 178 KB · 53 KB savings available
Info::
Within 1MB page-weight target
Got: 178 KB
Info::
~53 KB of savings available
Info::
2 third-party resources (0% of weight)
18 resources · 178.2 KiB · 2 third-party Within 1MB page-weight target
JavaScript 79% · 140.7 KiB
Document 12% · 20.6 KiB
CSS 8% · 14.3 KiB
Image 1% · 2.1 KiB
Other 0% · 436 B
~53.1 KiB of savings available
Remove unused JavaScript: 53.1 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 18 resources | 178.2 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
Render-Blocking Resources
No render-blocking resources detected
No render-blocking resources detected
Info::
No render-blocking resources detected in <head>
A+Third-Party ResourcesNo third-party resources detectedPASS
Third-Party Resources
No third-party resources detected
No third-party resources detected
Network Waterfall18 requests over 3378msINFO
Network Waterfall
18 requests over 3378ms
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
28% of JavaScript execution is third-party
First-party Third-party 232ms · 0KB · €3/mo
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 232ms | 0 KB | — | €3/mo | Costly |
Unattributable
Other
Execution 232ms
Transfer 0 KB
Monthly Cost €3/mo
These scripts may cost more than they're worth
- Unattributable adds 232ms and costs ~€3/month
Unattributable takes 232ms 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
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.