https://trystencil.org
Performance
· 22 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.SCORE
86
GRADE
B
FIX
2
REVIEW
4
PASS
13
INFO
3
Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
86
97
100
100
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
640 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.48 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
41 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.001
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.08 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.
2.64 s
Page Load Progression
778 ms
1.6 s 2.3 s 3.1 s 3.9 s 4.7 s 5.4 s
6.2 sChecks
2213 PASS 4 REVIEW 2 FIX
FPage Weight BudgetAction2.6 MB transferred, 100 requestsFIX
Page Weight Budget
Action2.6 MB transferred, 100 requests
2.6 MB transferred, 100 requests
Warning::
Page weighs 4.7 MB (2.6 MB transferred)
Warning::
Images are 1.7 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 1.7 MB
Warning::
JavaScript is 738 KB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 738 KB
Info::
100 HTTP requests
Info::
Estimated 0.55 g CO2 per page load
2.6 MB transferred
100 requests
0.55 g CO2 per page load
Images 1.7 MiB 65%
JavaScript 738.1 KiB 27%
Fonts 101.9 KiB 4%
CSS 44.2 KiB 2%
Other 33.4 KiB 1%
HTML 20.9 KiB 1%
Other 6.2 KiB 0%
Other 934 B 0%
Other 881 B 0%
Other 471 B 0%
0 2.4 MB 4.9 MB
Over budget
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Why this matters
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Why this matters
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
DHTTP CachingActionno-store (uncacheable)FIX
HTTP Caching
Actionno-store (uncacheable)
no-store (uncacheable)
Info::
Cache-Control: no-store prevents all caching
Intentional for dynamic content, but increases server load for every page view.
Got: private, no-cache, no-store, max-age=0, must-revalidate
Info::
No ETag or Last-Modified header
Conditional requests (304 Not Modified) are not possible without validators.
Cache-Control
private, no-cache, no-store, max-age=0, must-revalidate
| Directive | Value | Meaning |
|---|---|---|
| private | — | Only browser cache, not CDN/proxy |
| no-cache | — | Cache but always revalidate first |
| no-store | — | Never cache this response |
| max-age | 0 | Cache for 0 seconds |
| must-revalidate | — | Must recheck with server after expiry |
BImage Optimization25 images, 0 KB saveableREVIEW
Image Optimization
25 images, 0 KB saveable
25 images, 0 KB saveable
Info::
All images are well-optimized
25 images 1.6 MB
0 oversized -0 KB
22 legacy format
0 missing dimensions CLS risk
CJS Execution CostAction1310ms total JS executionREVIEW
JS Execution Cost
Action1310ms total JS execution
1310ms total JS execution
Warning::
https://trystencil.org/: 469ms CPU time
Warning::
https://trystencil.org/_next/static/chunks/30c3f2b...: 383ms CPU time
Info::
https://trystencil.org/_next/static/chunks/23f1435...: 191ms CPU time
Info::
Unattributable: 162ms CPU time
Info::
https://trystencil.org/_next/static/chunks/a3c38d7...: 104ms CPU time
Main Thread Breakdown
Script Evaluation 47% Style & Layout 22% Other 19% Script Parsing & Compilation 5% Rendering 5%
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://trystencil.org/ | 469ms | 16ms | 3ms | 1st |
| https://trystencil.org/_next/static/chunks/30c3f2be920d33a3.js | 383ms | 317ms | 7ms | 1st |
| https://trystencil.org/_next/static/chunks/23f14350963dfe8c.js | 191ms | 174ms | 0ms | 1st |
| Unattributable | 162ms | 10ms | 0ms | 1st |
| https://trystencil.org/_next/static/chunks/a3c38d7b7eff6aa9.js | 104ms | 90ms | 4ms | 1st |
CJS BundlesAction37 scripts, 182 KB unusedREVIEW
JS Bundles
Action37 scripts, 182 KB unused
37 scripts, 182 KB unused
Warning::
https://trystencil.org/_next/static/chunks/e0c2554...: 64 KB unused (76%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://trystencil.org/_next/static/chunks/b9b9bb0...: 49 KB unused (90%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://trystencil.org/_next/static/chunks/47e74b3...: 49 KB unused (87%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://trystencil.org/_next/static/chunks/30c3f2b...: 21 KB unused (30%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 182 KB
182 KB unused JavaScript
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://trystencil.org/_next/static/chunks/e0c25548b612ef82.js | 84 KB | 64 KB (76%) | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/b9b9bb0b2d1bc7a4.js | 59 KB | 49 KB (90%) | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/47e74b3ca15ea91f.js | 57 KB | 49 KB (87%) | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/30c3f2be920d33a3.js | 71 KB | 21 KB (30%) | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/5d27af82d32891a4.js | 11 KB | — | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/bc9336ebcad75a2d.js | 57 KB | — | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/48da1cbbd4d1a93d.js | 1 KB | — | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/e767791ab1bb9364.js | 8 KB | — | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/8f865f3963f525d3.js | 3 KB | — | ✓ | 1st |
| https://trystencil.org/_next/static/chunks/40236cc019049f5a.js | 9 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
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
CPage Weight InventoryAction100 resources · 2.6 MB · 182 KB savings availableREVIEW
Page Weight Inventory
Action100 resources · 2.6 MB · 182 KB savings available
100 resources · 2.6 MB · 182 KB savings available
Warning::
Page weight 2.6 MB exceeds 1 MB target by 1.6 MB
Got: 2.6 MB Expected: ≤ 1 MB
Info::
~182 KB of savings available
Info::
4 third-party resources (0% of weight)
100 resources · 2.6 MiB · 4 third-party 1.6 MiB over 1MB target
Image 65% · 1.7 MiB
JavaScript 27% · 738.1 KiB
Font 4% · 101.9 KiB
CSS 2% · 44.2 KiB
Other 1% · 35.7 KiB
Document 1% · 20.9 KiB
~182.5 KiB of savings available
Remove unused JavaScript: 182.5 KiB
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 100 resources | 2.6 MiB | ||||||
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 (10.2 KiB of 2.6 MiB)
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+Font Loading4 fonts (102 KB)PASS
Font Loading
4 fonts (102 KB)
4 fonts (102 KB)
Info::
4 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
4
102 KB total
Render-blocking
0
of 4
Dominant font-display
swap
Most common across fonts
Font loading timeline
Transfer FOIT (block) FOUT (swap)
dc6d2a64e9dbf3bc-s.p.4b... woff2 swap
Size 36 KB
Load time 67 ms
Start 618 ms
Risk FOUT — text flashes from fallback to web font
017d9bea37084d9b-s.p.a6... woff2 swap
Size 41 KB
Load time 79 ms
Start 619 ms
Risk FOUT — text flashes from fallback to web font
f1a9db6354730b0f-s.p.69... woff2 swap
Size 11 KB
Load time 33 ms
Start 619 ms
Risk FOUT — text flashes from fallback to web font
ae2df52ec52db659-s.p.9e... woff2 swap
Size 15 KB
Load time 18 ms
Start 885 ms
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 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+Document CompressionDocument response uses brotliPASS
Document Compression
Document response uses brotli
Document response uses brotli
Info::
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 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+Main HTML Cache-ControlMain HTML uses no-store -- correct for sensitive/dynamic contentPASS
Main HTML Cache-Control
Main HTML uses no-store -- correct for sensitive/dynamic content
Main HTML uses no-store -- correct for sensitive/dynamic content
Info::
Main HTML uses no-store -- correct for sensitive/dynamic content
Got: private, no-cache, no-store, max-age=0, must-revalidate
A+Server-Timing Observability3 Server-Timing entries advertisedPASS
Server-Timing Observability
3 Server-Timing entries advertised
3 Server-Timing entries advertised
Info::
Server-Timing header advertises 3 timing entries
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: rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch
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+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: Cloudflare
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 Waterfall100 requests over 6021msINFO
Network Waterfall
100 requests over 6021ms
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Image Optimization37 images, 2578 KB total, 1627 KB wastedINFO
Image Optimization
37 images, 2578 KB total, 1627 KB wasted
Image Optimization Audit
Total Images
37
Total Size
2578 KB
Oversized
22
Wasted
1627 KB
37 missing dimensions 16 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.