https://grocery-e-commerce-p-gd7t.bolt.host

Performance

· 26 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Mobile Desktop

Performance

Accessibility

Best Practices

SEO

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

3.80 s

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

7.39 s

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

23 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.

4.54 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.

7.53 s

Page Load Progression

566 ms

1.1 s

1.7 s

2.3 s

2.8 s

3.4 s

4.0 s

4.5 s

Checks

17 PASS 5 REVIEW 1 FIX

Third-Party Impact

Action

75% third-party, 0 ms blocking

FIX

75% third-party, 0 ms blocking

Third-party code accounts for 75% of page weight (743.4 KiB of 988.5 KiB)

Third-party blocking time is low (0 ms)

25%

75%

First-party Third-party

JS Execution Cost

991ms total JS execution

REVIEW

991ms total JS execution

https://grocery-e-commerce-p-gd7t.bolt.host/: 396ms CPU time

Unattributable: 369ms CPU time

https://grocery-e-commerce-p-gd7t.bolt.host/assets...: 226ms CPU time

Main Thread Breakdown

Other 47% Script Evaluation 27% Style & Layout 15% Rendering 10%

Script	Total	Scripting	Parse/Compile	Party
https://grocery-e-commerce-p-gd7t.bolt.host/	396ms	68ms	2ms	1st
Unattributable	369ms	10ms	0ms	1st
https://grocery-e-commerce-p-gd7t.bolt.host/assets/index-DeUdAHUR.js	226ms	186ms	2ms	1st

HTTP/3 (QUIC)

HTTP/3 not advertised

REVIEW

HTTP/3 not advertised

HTTP/3 (QUIC) is not advertised

HTTP/3 isn't advertised via Alt-Svc and the worker didn't negotiate h3. HTTP/3 reduces handshake latency (1-RTT instead of 2-3 RTTs) and is more resilient on lossy connections. Most modern CDNs (Cloudflare, Fastly, AWS CloudFront, Google Cloud CDN) support HTTP/3 with a single config switch -- consider enabling for mobile-heavy workloads.

Server-Timing Observability

No Server-Timing header found

REVIEW

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

HTTP Caching

public,max-age=0,must-revalidate

REVIEW

public,max-age=0,must-revalidate

Cache-Control header is set

Got: public,max-age=0,must-revalidate

No ETag or Last-Modified header

Conditional requests (304 Not Modified) are not possible without validators.

Cache-Control

public,max-age=0,must-revalidate

Directive	Value	Meaning
public	—	Any cache may store this response
max-age	0	Cache for 0 seconds
must-revalidate	—	Must recheck with server after expiry

Page Weight Budget

988 KB transferred, 37 requests

PASS

988 KB transferred, 37 requests

Page weighs 1.6 MB (988 KB transferred)

37 HTTP requests

Estimated 0.20 g CO2 per page load

988 KB transferred

37 requests

0.20 g CO2 per page load

Images 653.9 KiB 66%

JavaScript 234.5 KiB 24%

Fonts 78.0 KiB 8%

CSS 9.4 KiB 1%

Other 9.0 KiB 1%

HTML 2.0 KiB 0%

Other 1.8 KiB 0%

Other 0 B 0%

0 2.4 MB 4.9 MB

Under budget

A+

Text Compression

All text resources are compressed

PASS

All text resources are compressed

All text resources are properly compressed.

A+

Image Optimization

15 images, 0 KB saveable

PASS

15 images, 0 KB saveable

All images are well-optimized

15 images 654 KB

0 oversized -0 KB

0 legacy format

0 missing dimensions CLS risk

A+

Font Loading

2 fonts (78 KB)

PASS

2 fonts (78 KB)

2 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

78 KB total

Render-blocking

of 2

Dominant font-display

swap

Most common across fonts

Font loading timeline

Transfer FOIT (block) FOUT (swap)

nwpCtLGrOAZMl5nJ_wfgRg3... woff2 swap

Size 31 KB

Load time 51 ms

Start 991 ms

Risk FOUT — text flashes from fallback to web font

UcC73FwrK3iLTeHuS_nVMrM... woff2 swap

Size 47 KB

Load time 54 ms

Start 1.0 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 Bundles

2 scripts, 46 KB unused

PASS

2 scripts, 46 KB unused

https://grocery-e-commerce-p-gd7t.bolt.host/assets...: 46 KB unused (20%)

Consider code splitting or tree shaking to reduce unused code.

Total unused JavaScript: 46 KB

46 KB unused JavaScript

Downloaded but never executed on this page.

Script	Size	Unused	Minified	Party
https://grocery-e-commerce-p-gd7t.bolt.host/assets/index-DeUdAHUR.js	234 KB	46 KB (20%)	✓	1st
https://bolt.new/badge.js?s=5044cfd4-c32a-4f4f-a1ca-736fd5f5ede9	0 KB	—	✓	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

A+

Resource Caching

All resources properly cached

PASS

All resources properly cached

No caching issues found

All static resources have appropriate caching headers.

A+

Critical Rendering Path

No render-blocking resources

PASS

No render-blocking resources

No render-blocking resources detected

A+

Resource Hints

No optimization needed

PASS

No optimization needed

No resource hint issues

A+

Document Compression

Document response uses brotli

PASS

Document response uses brotli

Main HTML response uses brotli (Content-Encoding: br)

Brotli is the best text-compression algorithm for general use, ~20% smaller than gzip on average (40% on smaller files). Modern browsers all support it.

A+

LCP Image Preload

LCP preload audit not available

PASS

LCP preload audit not available

LCP image preload audit not available for this scan

A+

Main HTML Cache-Control

Main HTML max-age=0 (≤ 5min) is appropriate

PASS

Main HTML max-age=0 (≤ 5min) is appropriate

Got: public,max-age=0,must-revalidate

A+

Server Response Intelligence

3 server-response signal(s) detected

PASS

3 server-response signal(s) detected

`Cache-Status` header present (RFC 9211): "Netlify Edge"; fwd=miss; fwd-status=200; stored

The page returns a `Cache-Status` header -- the standardized way for CDNs and caches to communicate per-hop cache state to debugging tools. Format: `Cache-Status: cdn-name; hit; ttl=300` (or `; fwd=miss` / `; fwd=stale`). Standard alternative to vendor-specific `X-Cache` patterns each CDN had historically. Cloudflare, Fastly, and Akamai all support emitting it.

`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).

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.

Page Weight Inventory

37 resources · 988 KB · 46 KB savings available

PASS

37 resources · 988 KB · 46 KB savings available

Within 1MB page-weight target

Got: 988 KB

33 third-party resources (75% of weight)

1 resources over 200KB

37 resources · 988.5 KiB · 33 third-party Within 1MB page-weight target

Image 66% · 653.9 KiB

JavaScript 24% · 234.5 KiB

Font 8% · 78.0 KiB

CSS 1% · 9.4 KiB

Other 1% · 9.0 KiB

Document 0% · 3.8 KiB

~46.1 KiB of savings available

Remove unused JavaScript: 46.1 KiB

#	Resource	Type	Size	Cache	Unused	3rd party	Issues

37 resources			988.5 KiB

A+

Render-Blocking Resources

No render-blocking resources detected

PASS

No render-blocking resources detected

No render-blocking resources detected in <head>

A+

Third-Party Resources

No third-party resources detected

PASS

No third-party resources detected

A+

JavaScript Blocking

No render-blocking JS or document.write usage detected

PASS

No render-blocking JS or document.write usage detected

No JavaScript blocking issues detected

A+

CSS Performance Depth

No CSS performance depth issues detected

PASS

No CSS performance depth issues detected

Asset Compression

No text asset hosts to measure

INFO

No text asset hosts to measure

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 Waterfall

37 requests over 2195ms

INFO

HTML JavaScript CSS Images Fonts XHR/Fetch Other

Image Optimization

23 images, 0 KB total, 0 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

0 KB

Oversized

23 missing dimensions 2 missing lazy loading

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.