https://serebrokubachi.ru
Performance
· 28 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
87
GRADE
B
FIX
2
REVIEW
8
PASS
13
INFO
5
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
68
92
96
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
1.80 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.25 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
369 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.213
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
17.11 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.
6.69 s
Page Load Progression
2.0 s 4.0 s 6.0 s 8.0 s 10.0 s
12.0 s
14.0 s
16.0 sChecks
2813 PASS 8 REVIEW 2 FIX
FJS Execution CostAction4320ms total JS executionFIX
JS Execution Cost
Action4320ms total JS execution
4320ms total JS execution
Warning::
https://serebrokubachi.ru/: 2796ms CPU time
Warning::
Unattributable: 450ms CPU time
Warning::
https://www.googletagmanager.com/gtag/js?id=G-R35C...: 382ms CPU time
Info::
https://mc.yandex.com/metrika/tag.js: 243ms CPU time
Info::
https://www.googletagmanager.com/gtm.js?id=GTM-TVL...: 200ms CPU time
Info::
Third-party scripts: 824ms (19% of total)
Main Thread Breakdown
Other 40% Script Evaluation 21% Rendering 19% Style & Layout 14% Script Parsing & Compilation 4%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://serebrokubachi.ru/ | 2796ms | 75ms | 14ms | 1st |
| Unattributable | 450ms | 29ms | 0ms | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-R35CE3JWHQ&cx=c>m=4e6aj0 | 382ms | 313ms | 64ms | 3rd |
| https://mc.yandex.com/metrika/tag.js | 243ms | 207ms | 24ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TVLPKZ9C | 200ms | 161ms | 38ms | 3rd |
| https://serebrokubachi.ru/wp-content/litespeed/js/4d5bf675c449f0a3a201a99ece1eb840.js?ver=f03cc | 107ms | 41ms | 7ms | 1st |
| https://serebrokubachi.ru/wp-includes/js/jquery/jquery.min.js?ver=3.7.1 | 76ms | 65ms | 8ms | 1st |
| sk-visual-product-frame-js-js-after | 66ms | 21ms | 0ms | 1st |
FHTTP CachingActionNo cache headersFIX
HTTP Caching
ActionNo cache headers
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.
BPage Weight Budget1.1 MB transferred, 99 requestsREVIEW
Page Weight Budget
1.1 MB transferred, 99 requests
1.1 MB transferred, 99 requests
Info::
Page weighs 2.3 MB (1.1 MB transferred)
Info::
99 HTTP requests
Info::
Estimated 0.22 g CO2 per page load
1.1 MB transferred
99 requests
0.22 g CO2 per page load
JavaScript 448.4 KiB 41%
Images 423.8 KiB 39%
Other 68.3 KiB 6%
Fonts 64.1 KiB 6%
HTML 44.0 KiB 4%
CSS 36.8 KiB 3%
Other 1.9 KiB 0%
Other 550 B 0%
0 2.4 MB 4.9 MB
Under budget
BImage Optimization65 images, 0 KB saveableREVIEW
Image Optimization
65 images, 0 KB saveable
65 images, 0 KB saveable
Info::
All images are well-optimized
65 images 424 KB
0 oversized -0 KB
21 legacy format
0 missing dimensions CLS risk
CJS BundlesAction14 scripts, 174 KB unusedREVIEW
JS Bundles
Action14 scripts, 174 KB unused
14 scripts, 174 KB unused
Warning::
https://www.googletagmanager.com/gtag/js?id=G-R35C...: 73 KB unused (39%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-TVL...: 64 KB unused (48%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://mc.yandex.com/metrika/tag.js: 37 KB unused (54%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 174 KB
174 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-R35CE3JWHQ&cx=c>m=4e6aj0 | 189 KB | 73 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TVLPKZ9C | 136 KB | 64 KB (48%) | ✓ | 3rd |
| https://mc.yandex.com/metrika/tag.js | 69 KB | 37 KB (54%) | ✓ | 3rd |
| https://serebrokubachi.ru/wp-content/plugins/duracelltomi-google-tag-manager/build/gtm4wp-ecommerce-generic.js?ver=2.0.6 | 1 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/litespeed/js/4d5bf675c449f0a3a201a99ece1eb840.js?ver=f03cc | 19 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/litespeed/js/13ccc689bfa1e3b0e0896b979c3b1ec3.js?ver=a482a | 1 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/plugins/litespeed-cache/assets/js/css_async.min.js | 1 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/themes/flatsome/assets/js/flatsome.js?ver=c70e5a9a66ada87bcb37 | 18 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/themes/flatsome/assets/js/chunk.slider.js?ver=3.20.11 | 13 KB | — | ✓ | 1st |
| https://serebrokubachi.ru/wp-content/themes/flatsome/assets/js/chunk.popups.js?ver=3.20.11 | 7 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
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
BDocument CompressionDocument response uses gzip; brotli would be ~20% smallerREVIEW
Document Compression
Document response uses gzip; brotli would be ~20% smaller
Document response uses gzip; brotli would be ~20% smaller
Info::
Main HTML response uses gzip (brotli would be ~20% smaller)
All current browsers support brotli. Most CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel, Netlify) can switch from gzip to brotli with a single config flag. Origin servers (nginx, Apache) need a brotli module compiled in -- nginx-brotli or Apache mod_brotli.
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
Main HTML Cache-Control
No Cache-Control header on main HTML response
No Cache-Control header on main HTML response
Info::
Main HTML response has no Cache-Control header
Without an explicit Cache-Control, browsers fall back to heuristic caching (~10% of Last-Modified age). Set `Cache-Control: no-cache` or `max-age=300` for HTML to control freshness explicitly -- prevents stale auth state and SPA shell drift.
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
Server-Timing Observability
No Server-Timing header found
No Server-Timing header found
Info::
No Server-Timing header found
Server-Timing exposes backend timing breakdowns to browser DevTools (e.g., `db: 45ms; render: 120ms; cache: 2ms`). Useful for diagnosing slow pages without backend log access. Most modern frameworks (Next.js, Cloudflare Workers, Fastly) emit it automatically; absence on a managed platform usually means telemetry headers are stripped at the edge.
BJavaScript Blocking2 JS blocking issue(s) detectedREVIEW
JavaScript Blocking
2 JS blocking issue(s) detected
2 JS blocking issue(s) detected
Warning::
2 render-blocking <script src> tag(s) without async/defer
Each `<script src=...>` without `async`, `defer`, or `type="module"` blocks HTML parsing while the browser fetches and executes it. The block lasts the entire round-trip + execution time -- on slow networks this translates directly into LCP delay. Add `defer` (executes after parse, in source order) for scripts that interact with the DOM, or `async` (executes whenever ready) for analytics / independent scripts. Module scripts (`type="module"`) are deferred by default.
Warning::
Total JS execution time is 4.3 s -- over the 3.5s budget
Total JavaScript execution (parse + compile + run) across all scripts exceeds 3.5 seconds. On low-end devices that becomes 7-15+ seconds and shows up directly in TBT and INP. Reduce by: tree-shaking unused dependencies, code-splitting (dynamic `import()`), removing or deferring third-party tracking, and replacing heavy frameworks where they're not needed.
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
AThird-Party Impact37% third-party, 0 ms blockingPASS
Third-Party Impact
37% third-party, 0 ms blocking
37% third-party, 0 ms blocking
Info::
Third-party code accounts for 37% of page weight (401.1 KiB of 1.1 MiB)
Info::
Third-party blocking time is low (0 ms)
63%
37%
First-party Third-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 Loading5 fonts (64 KB)PASS
Font Loading
5 fonts (64 KB)
5 fonts (64 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
5
64 KB total
Render-blocking
0
of 5
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
S6uyw4BMUTPHjx4wXg.woff2 woff2 swap
Size 23 KB
Load time 147 ms
Start 11.2 s
Risk FOUT — text flashes from fallback to web font
fl-icons.woff2 woff2 swap
Size 7 KB
Load time 147 ms
Start 11.2 s
Risk FOUT — text flashes from fallback to web font
S6u9w4BMUTPHh6UVSwiPGQ.... woff2 swap
Size 23 KB
Load time 157 ms
Start 11.2 s
Risk FOUT — text flashes from fallback to web font
S6uyw4BMUTPHjxAwXjeu.woff2 woff2 swap
Size 6 KB
Load time 157 ms
Start 11.2 s
Risk FOUT — text flashes from fallback to web font
S6u9w4BMUTPHh6UVSwaPGR_... woff2 swap
Size 5 KB
Load time 162 ms
Start 11.2 s
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 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 Hints20 hints, 0 missing preconnectsPASS
Resource Hints
20 hints, 0 missing preconnects
20 hints, 0 missing preconnects
Info::
Page uses 20 resource hint(s)
Current Resource Hints
preconnect 1
preload 3
dns-prefetch
+1
11prefetch 5
20 resource hints configured
A+HTTP/3 (QUIC)HTTP/3 advertised via Alt-SvcPASS
HTTP/3 (QUIC)
HTTP/3 advertised via Alt-Svc
HTTP/3 advertised via Alt-Svc
Info::
HTTP/3 (QUIC) is supported
First-load mobile users on cellular networks see meaningful latency improvements with HTTP/3. The QUIC transport collapses TLS + TCP handshakes into one and recovers faster from packet loss.
A+LCP Image PreloadLCP preload audit not availablePASS
LCP Image Preload
LCP preload audit not available
LCP preload audit not available
Info::
LCP image preload audit not available for this scan
A+Server Response Intelligence2 server-response signal(s) detectedPASS
Server Response Intelligence
2 server-response signal(s) detected
2 server-response signal(s) detected
Info::
`Vary` header declared: Accept-Encoding
The page declares a `Vary` header, telling downstream caches which request headers the response varies on. Critical for content-negotiated responses (compression, language, cookies, device class).
Info::
No `ETag` or `Last-Modified` -- conditional GET not supported
Without either header, browsers can't issue conditional GETs and refresh always re-downloads the full response body even when nothing changed. Add `ETag: "<hash>"` (or `Last-Modified: <date>`) on cacheable responses; the server returns 304 Not Modified when the client's cached copy is still valid, saving bandwidth.
A+Page Weight Inventory99 resources · 1.1 MB · 174 KB savings availablePASS
Page Weight Inventory
99 resources · 1.1 MB · 174 KB savings available
99 resources · 1.1 MB · 174 KB savings available
Warning::
Page weight 1.1 MB exceeds 1 MB target by 64 KB
Got: 1.1 MB Expected: ≤ 1 MB
Info::
~174 KB of savings available
Info::
17 third-party resources (37% of weight)
99 resources · 1.1 MiB · 17 third-party 63.9 KiB over 1MB target
JavaScript 46% · 503.6 KiB
Image 40% · 433.3 KiB
Font 6% · 64.1 KiB
Document 4% · 44.0 KiB
CSS 3% · 36.8 KiB
Other 1% · 6.1 KiB
~173.8 KiB of savings available
Remove unused JavaScript: 173.8 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 99 resources | 1.1 MiB | ||||||
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
A+CSS Performance DepthNo CSS performance depth issues detectedPASS
CSS Performance Depth
No CSS performance depth issues detected
No CSS performance depth issues detected
Info::
No CSS performance depth issues detected
Asset CompressionNo text asset hosts to measureINFO
Asset Compression
No text asset hosts to measure
No text asset hosts to measure
Info::
No third-party or subdomain host served enough text assets to measure
Asset compression is measured per host, from one HEAD request against a sampled resource. Pages that serve all their JS and CSS from the document's own origin are covered by the document compression check instead.
Network Waterfall99 requests over 15097msINFO
Network Waterfall
99 requests over 15097ms
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
19% of JavaScript execution is third-party
First-party Third-party 824ms · 394KB · ₽429/mo
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Google Tag Manager www.googletagmanager.com | Tag Manager | 382ms | 189 KB | 39% | ₽199/mo | Costly |
mc.yandex.com mc.yandex.com | Other | 243ms | 69 KB | 54% | ₽126/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 200ms | 136 KB | 48% | ₽104/mo | Costly |
Google Tag Manager
Tag Manager
Execution 382ms
Transfer 189 KB
Unused 39%
Monthly Cost ₽199/mo
mc.yandex.com
Other
Execution 243ms
Transfer 69 KB
Unused 54%
Monthly Cost ₽126/mo
Google Tag Manager
Tag Manager
Execution 200ms
Transfer 136 KB
Unused 48%
Monthly Cost ₽104/mo
These scripts may cost more than they're worth
- Google Tag Manager adds 382ms and costs ~₽199/month
- mc.yandex.com adds 243ms and costs ~₽126/month
- Google Tag Manager adds 200ms and costs ~₽104/month
Google Tag Manager takes 382ms 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
mc.yandex.com takes 243ms 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
54% of mc.yandex.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
Google Tag Manager 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
Real-User Performance (CrUX)Field metrics from the Chrome User Experience ReportINFO
Real-User Performance (CrUX)
Field metrics from the Chrome User Experience Report
Chrome User Experience (CrUX)
Real-user metrics from the Chrome UX Report (2026-09-21 — 2026-10-18)
LCP (p75)
2028 ms
80% good
INP (p75)
120 ms
92% good
CLS (p75)
0.000
99% good
FCP (p75)
1901 ms
TTFB (p75)
1887 ms
This origin passes Core Web Vitals assessment
Image Optimization48 images, 184 KB total, 13 KB wastedINFO
Image Optimization
48 images, 184 KB total, 13 KB wasted
Image Optimization Audit
Total Images
48
Total Size
184 KB
Oversized
4
Wasted
13 KB
1 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.