Performance

· 15 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

100

Accessibility

Best Practices

100

SEO

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

353 ms

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

769 ms

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

96 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.

2.45 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.

5.31 s

Page Load Progression

375 ms

750 ms

1.1 s

1.5 s

1.9 s

2.2 s

2.6 s

3.0 s

Checks

6 PASS 3 REVIEW 4 FIX

Page Weight Budget

Action

3.4 MB transferred, 157 requests

FIX

3.4 MB transferred, 157 requests

Page weighs 7.3 MB (3.4 MB transferred)

JavaScript is 1.5 MB — consider code splitting or lazy loading

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Got: 1.5 MB

Images are 1.4 MB — compress or use modern formats

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Got: 1.4 MB

Fonts are 301 KB — consider subsetting or using system fonts

Subset fonts to include only used characters, or switch to system font stacks.

Got: 301 KB

157 HTTP requests — consider bundling or reducing

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Estimated 0.71 g CO2 per page load

3.4 MB transferred

157 requests

0.71 g CO2 per page load

JavaScript 1.5 MiB 45%

Images 1.4 MiB 42%

Fonts 301.4 KiB 9%

Other 48.1 KiB 1%

HTML 45.7 KiB 1%

Other 26.0 KiB 1%

Other 18.2 KiB 1%

CSS 15.6 KiB 0%

Other 0 B 0%

0 2.4 MB 4.9 MB

Over budget

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

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

Subset fonts to include only used characters, or switch to system font stacks.

Why this matters

Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).

Source: web.dev font loading

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

Third-Party Impact

Action

67% third-party, 0 ms blocking

FIX

67% third-party, 0 ms blocking

Third-party code accounts for 67% of page weight (2.3 MiB of 3.4 MiB)

Third-party blocking time is low (0 ms)

33%

67%

First-party Third-party

JS Bundles

Action

61 scripts, 644 KB unused

FIX

61 scripts, 644 KB unused

https://cdn.amplitude.com/libs/plugin-session-repl...: 100 KB unused (78%)