https://overbid.eu
Performance
· 21 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
94
GRADE
A
FIX
1
REVIEW
4
PASS
14
INFO
2
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
98
100
100
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
584 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
659 ms
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
0 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.017
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.55 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.
659 ms
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
2114 PASS 4 REVIEW 1 FIX
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.
BImage Optimization61 images, 0 KB saveableREVIEW
Image Optimization
61 images, 0 KB saveable
61 images, 0 KB saveable
Info::
All images are well-optimized
61 images 79 KB
0 oversized -0 KB
61 legacy format
0 missing dimensions CLS risk
BCompression AlgorithmMain response uses gzip; brotli would be ~20% smallerREVIEW
Compression Algorithm
Main response uses gzip; brotli would be ~20% smaller
Main 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.
A+Page Weight Budget294 KB transferred, 76 requestsPASS
Page Weight Budget
294 KB transferred, 76 requests
294 KB transferred, 76 requests
Info::
Page weighs 529 KB (294 KB transferred)
Info::
76 HTTP requests
Info::
Estimated 0.06 g CO2 per page load
294 KB transferred
76 requests
0.06 g CO2 per page load
Fonts 165.1 KiB 56%
Images 79.4 KiB 27%
JavaScript 23.4 KiB 8%
HTML 12.4 KiB 4%
CSS 9.6 KiB 3%
Other 3.5 KiB 1%
Other 688 B 0%
Other 220 B 0%
0 2.4 MB 4.9 MB
Under budget
A+Third-Party Impact0% third-party, 0 ms blockingPASS
Third-Party Impact
0% third-party, 0 ms blocking
0% third-party, 0 ms blocking
Info::
Third-party code accounts for 0% of page weight (220 B of 294.3 KiB)
Info::
Third-party blocking time is low (0 ms)
100%
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+JS Execution Cost455ms total JS executionPASS
JS Execution Cost
455ms total JS execution
455ms total JS execution
Warning::
Unattributable: 285ms CPU time
Info::
https://overbid.eu/: 170ms CPU time
Main Thread Breakdown
Other 56% Style & Layout 26% Script Evaluation 8% Rendering 6% Parse HTML & CSS 4%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 285ms | 5ms | 0ms | 1st |
| https://overbid.eu/ | 170ms | 6ms | 1ms | 1st |
A+Font Loading6 fonts (165 KB)PASS
Font Loading
6 fonts (165 KB)
6 fonts (165 KB)
Info::
6 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
6
165 KB total
Render-blocking
0
of 6
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
InstrumentSans-400.woff2 woff2 swap
Size 27 KB
Load time 524 ms
Start 1.4 s
Risk FOUT — text flashes from fallback to web font
InstrumentSans-700.woff2 woff2 swap
Size 27 KB
Load time 523 ms
Start 1.4 s
Risk FOUT — text flashes from fallback to web font
InstrumentSerif-400i.woff2 woff2 swap
Size 28 KB
Load time 827 ms
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
InstrumentSerif-400.woff2 woff2 swap
Size 27 KB
Load time 823 ms
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
InstrumentSans-500.woff2 woff2 swap
Size 28 KB
Load time 829 ms
Start 2.0 s
Risk FOUT — text flashes from fallback to web font
InstrumentSans-600.woff2 woff2 swap
Size 28 KB
Load time 831 ms
Start 2.0 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+JS Bundles3 scripts, 0 KB unusedPASS
JS Bundles
3 scripts, 0 KB unused
3 scripts, 0 KB unused
0 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://overbid.eu/static/vendor/htmx-2.0.9.min.js | 18 KB | — | ✓ | 1st |
| https://overbid.eu/static/app.js | 3 KB | — | ✓ | 1st |
| https://overbid.eu/js/pa-ohNj7Mjm0HNZ9DyDRhNFd.js | 3 KB | — | ✓ | 1st |
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+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 Inventory76 resources · 294 KB · 0 KB savings availablePASS
Page Weight Inventory
76 resources · 294 KB · 0 KB savings available
76 resources · 294 KB · 0 KB savings available
Info::
Within 1MB page-weight target
Got: 294 KB
Info::
1 third-party resources (0% of weight)
76 resources · 294.3 KiB · 1 third-party Within 1MB page-weight target
Font 56% · 165.1 KiB
Image 28% · 82.9 KiB
JavaScript 8% · 23.4 KiB
Document 4% · 12.4 KiB
CSS 3% · 9.6 KiB
Other 0% · 908 B
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 76 resources | 294.3 KiB | ||||||
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: OVHcloud
Network Waterfall76 requests over 3543msINFO
Network Waterfall
76 requests over 3543ms
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Image Optimization115 images, 98 KB total, 0 KB wastedINFO
Image Optimization
115 images, 98 KB total, 0 KB wasted
Image Optimization Audit
Total Images
115
Total Size
98 KB
97 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.