Adding a Cache-Control header can significantly improve repeat-visit performance.
B
Image Optimization
12 images, 0 KB saveable
REVIEW
12 images, 0 KB saveable
Warning::
!
https://images.squarespace-cdn.com/content/v1/6047... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
12images5.6 MB
0oversized-0 KB
5legacy format
1missing dimensionsCLS risk
Set explicit width and height to prevent CLS.
Why this matters
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
B
HTTP/3 (QUIC)
HTTP/3 not advertised
REVIEW
HTTP/3 not advertised
Info::
i
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.
C
Compression Algorithm
Action
Main response served uncompressed
REVIEW
Main response served uncompressed
Info::
i
Main HTML response has no Content-Encoding (uncompressed)
The main HTML document is served without compression. The Text Compression section above lists the broader picture; for the main response specifically, even gzip would shave ~70-80% off most text payloads.
B
Main HTML Cache-Control
No Cache-Control header on main HTML response
REVIEW
No Cache-Control header on main HTML response
Info::
i
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.
B
Server-Timing Observability
No Server-Timing header found
REVIEW
No Server-Timing header found
Info::
i
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.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW
Green Hosting
No green hosting detected
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+
Font Loading
4 fonts (31 KB)
PASS
4 fonts (31 KB)
Info::
i
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
31 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
pxiByp8kv8JHgFVrLGT9Z1x...woff2swap
Size8 KB
Load time38 ms
Start775 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLDz8Z1x...woff2swap
Size8 KB
Load time40 ms
Start775 ms
RiskFOUT — text flashes from fallback to web font
pxiByp8kv8JHgFVrLCz7Z1x...woff2swap
Size8 KB
Load time45 ms
Start775 ms
RiskFOUT — text flashes from fallback to web font
pxiEyp8kv8JHgFVrJJfecnF...woff2swap
Size8 KB
Load time43 ms
Start923 ms
RiskFOUT — 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 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
2 hints, 0 missing preconnects
PASS
2 hints, 0 missing preconnects
Info::
✓
Page uses 2 resource hint(s)
Current Resource Hints
preconnect
2
preload—
dns-prefetch—
prefetch—
2 resource hints configured
A+
LCP Image Preload
LCP preload audit not available
PASS
LCP preload audit not available
Info::
✓
LCP image preload audit not available for this scan
A+
Server Response Intelligence
2 server-response signal(s) detected
PASS
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::
✓
`ETag` present -- conditional GET supported
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
JavaScript Blocking
1 JS blocking issue(s) detected
PASS
1 JS blocking issue(s) detected
Warning::
!
1 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.
Each `<link rel="stylesheet">` without a non-blocking `media` attribute holds up the first paint. Browsers download all of them before painting any content. Consolidate into 1-2 critical-path stylesheets; defer non-critical CSS via `<link rel="stylesheet" media="print" onload="this.media='all'">` or via the loadCSS pattern; inline above-the-fold CSS in `<style>` to short-circuit the request entirely.
Network Waterfall
78 requests over 2293ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
90%of JavaScript execution is third-party
First-party Third-party2571ms · 918KB · $15/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
assets.squarespace.com
assets.squarespace.com
Other
775ms
274 KB
64%
$4/mo
Costly
Unattributable
Unattributable
Other
450ms
0 KB
—
$3/mo
Costly
static1.squarespace.com
static1.squarespace.com
Other
304ms
37 KB
—
$2/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
224ms
157 KB
41%
$1/mo
Costly
assets.squarespace.com
assets.squarespace.com
Other
190ms
9 KB
—
$1/mo
Optional
assets.squarespace.com
assets.squarespace.com
Other
148ms
47 KB
58%
$1/mo
Optional
static1.squarespace.com
static1.squarespace.com
Other
106ms
4 KB
—
$1/mo
Optional
assets.squarespace.com
assets.squarespace.com
Other
86ms
42 KB
—
$0/mo
Optional
assets.squarespace.com
assets.squarespace.com
Other
68ms
168 KB
37%
$0/mo
Optional
assets.squarespace.com
assets.squarespace.com
Other
57ms
19 KB
—
$0/mo
Optional
static1.squarespace.com
static1.squarespace.com
Other
55ms
108 KB
—
$0/mo
Optional
definitions.sqspcdn.com
definitions.sqspcdn.com
Other
54ms
9 KB
—
$0/mo
Optional
assets.squarespace.com
assets.squarespace.com
Other
53ms
44 KB
98%
$0/mo
Optional
assets.squarespace.com
Other
Costly
Execution775ms
Transfer274 KB
Unused64%
Monthly Cost$4/mo
Unattributable
Other
Costly
Execution450ms
Transfer0 KB
Monthly Cost$3/mo
static1.squarespace.com
Other
Costly
Execution304ms
Transfer37 KB
Monthly Cost$2/mo
Google Tag Manager
Tag Manager
Costly
Execution224ms
Transfer157 KB
Unused41%
Monthly Cost$1/mo
assets.squarespace.com
Other
Optional
Execution190ms
Transfer9 KB
Monthly Cost$1/mo
assets.squarespace.com
Other
Optional
Execution148ms
Transfer47 KB
Unused58%
Monthly Cost$1/mo
static1.squarespace.com
Other
Optional
Execution106ms
Transfer4 KB
Monthly Cost$1/mo
assets.squarespace.com
Other
Optional
Execution86ms
Transfer42 KB
Monthly Cost$0/mo
assets.squarespace.com
Other
Optional
Execution68ms
Transfer168 KB
Unused37%
Monthly Cost$0/mo
assets.squarespace.com
Other
Optional
Execution57ms
Transfer19 KB
Monthly Cost$0/mo
static1.squarespace.com
Other
Optional
Execution55ms
Transfer108 KB
Monthly Cost$0/mo
definitions.sqspcdn.com
Other
Optional
Execution54ms
Transfer9 KB
Monthly Cost$0/mo
assets.squarespace.com
Other
Optional
Execution53ms
Transfer44 KB
Unused98%
Monthly Cost$0/mo
These scripts may cost more than they're worth
assets.squarespace.com adds 775ms and costs ~$4/month
Unattributable adds 450ms and costs ~$3/month
static1.squarespace.com adds 304ms and costs ~$2/month
Google Tag Manager adds 224ms and costs ~$1/month
90% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
Why this matters
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
assets.squarespace.com takes 775ms 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
64% of assets.squarespace.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
Unattributable takes 450ms 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
static1.squarespace.com takes 304ms 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
Google Tag Manager takes 224ms 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
58% of assets.squarespace.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
98% of assets.squarespace.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.