Lighthouse Performance

Name: PeerScripts
Rating: 5 (1 reviews)
Author: PeerScripts

Lighthouse monitors your store's Core Web Vitals and overall performance metrics. Track, analyze, and improve your storefront's speed and user experience.

Overview

Page performance directly impacts conversion rates and SEO rankings. Google uses Core Web Vitals as a ranking factor, making performance optimization essential. Lighthouse provides:

Core Web Vitals Tracking: LCP, CLS, and INP measurements
Device-Specific Testing: Mobile and desktop scores
Performance Scoring: 0-100 performance rating
Trend Analysis: Track improvements over time
Regression Detection: Alerts when performance drops

Getting Started

Running Your First Scan

Navigate to Lighthouse in the sidebar
Click New Scan
Select device type:
- Mobile (recommended): Simulates mobile device and network
- Desktop: Standard desktop conditions
Wait for scan to complete (30-60 seconds)
Review your scores and recommendations

Understanding Core Web Vitals

LCP (Largest Contentful Paint)

Measures how long it takes for the main content to load.

Score	Rating	User Experience
≤ 2.5s	Good	Content loads quickly
2.5-4s	Needs Improvement	Noticeable delay
> 4s	Poor	Users may abandon

Common Causes of Poor LCP:

Large hero images
Render-blocking resources
Slow server response
Client-side rendering delays

CLS (Cumulative Layout Shift)

Measures visual stability—how much the page layout shifts during loading.

Score	Rating	User Experience
≤ 0.1	Good	Stable, predictable layout
0.1-0.25	Needs Improvement	Some shifting
> 0.25	Poor	Frustrating shifts

Common Causes of Poor CLS:

Images without dimensions
Dynamically injected content
Web fonts causing text shift
Ads or embeds without reserved space

INP (Interaction to Next Paint)

Measures responsiveness—how quickly the page responds to user interaction.

Score	Rating	User Experience
≤ 200ms	Good	Feels instant
200-500ms	Needs Improvement	Slight delay
> 500ms	Poor	Feels sluggish

Common Causes of Poor INP:

Long JavaScript tasks
Heavy event handlers
Main thread blocking
Too many third-party scripts

Performance Score

Score Breakdown

The overall performance score (0-100) is a weighted average:

┌─────────────────────────────────────────────────────────────┐
│  PERFORMANCE SCORE: 72                                      │
│                                                             │
│  ┌─────────────────────────────────────────────────────┐   │
│  │  ████████████████████████████████░░░░░░░░░░░░░░░░░  │   │
│  │  0        25        50        75        100         │   │
│  └─────────────────────────────────────────────────────┘   │
│                                                             │
│  Score Composition:                                         │
│  ├─ LCP (25%):          2.8s     → 18/25 points            │
│  ├─ CLS (25%):          0.05     → 24/25 points            │
│  ├─ INP (25%):          280ms    → 20/25 points            │
│  └─ Other (25%):        Various  → 10/25 points            │
│                                                             │
│  Rating: Needs Improvement                                  │
└─────────────────────────────────────────────────────────────┘

Score Interpretation

Score	Rating	Action
90-100	Excellent	Maintain current performance
50-89	Needs Improvement	Address recommendations
0-49	Poor	Prioritize performance fixes

Additional Metrics

Beyond Core Web Vitals, Lighthouse also measures:

Accessibility Score

How accessible your store is for users with disabilities:

Color contrast
Alt text presence
Keyboard navigation
Screen reader compatibility

Best Practices Score

Adherence to web development best practices:

HTTPS usage
Safe JavaScript practices
Modern APIs
No deprecated features

SEO Score

Basic SEO requirements:

Meta tags present
Crawlable content
Mobile-friendly design
Structured data

Scan Results

Results Overview

┌─────────────────────────────────────────────────────────────────┐
│  LIGHTHOUSE SCAN RESULTS                                        │
│  Scanned: Jan 15, 2025 at 2:30 PM  •  Device: Mobile           │
│                                                                 │
│  ┌──────────┐ ┌──────────┐ ┌──────────┐ ┌──────────┐          │
│  │Performance│ │Accessibility│ │Best Practice│ │   SEO   │     │
│  │    72    │ │     85    │ │     92    │ │   95    │          │
│  └──────────┘ └──────────┘ └──────────┘ └──────────┘          │
│                                                                 │
│  CORE WEB VITALS                                                │
│  ┌────────────────────────────────────────────────────────┐    │
│  │ LCP    │ ████████████░░░░░░  │ 2.8s    │ Needs Work   │    │
│  │ CLS    │ ████████████████░░  │ 0.05    │ Good         │    │
│  │ INP    │ ██████████████░░░░  │ 280ms   │ Needs Work   │    │
│  └────────────────────────────────────────────────────────┘    │
│                                                                 │
│  [View Details]  [Export Report]  [Compare Scans]              │
└─────────────────────────────────────────────────────────────────┘

Recommendations

Each scan includes specific recommendations:

┌─────────────────────────────────────────────────────────────────┐
│  RECOMMENDATIONS                                                │
│                                                                 │
│  High Impact:                                                   │
│  ├─ Serve images in next-gen formats (WebP, AVIF)              │
│  │   Potential savings: 1.2s                                    │
│  │                                                              │
│  ├─ Eliminate render-blocking resources                         │
│  │   Potential savings: 0.8s                                    │
│  │                                                              │
│  └─ Reduce unused JavaScript                                    │
│     Potential savings: 0.5s                                     │
│                                                                 │
│  Medium Impact:                                                 │
│  ├─ Preconnect to required origins                              │
│  ├─ Enable text compression                                     │
│  └─ Avoid large layout shifts                                   │
└─────────────────────────────────────────────────────────────────┘

Scan History

Viewing Past Scans

Access 30 days of scan history:

Click History in the Lighthouse section
View all past scans with scores
Click any scan to see full details
Filter by device type or date range

Trend Analysis

Performance Score Trend (30 days)
100 ┤
 90 ┤                               ╭─────
 80 ┤              ╭────────────────╯
 70 ┤─────────────╯
 60 ┤
    └─────────────────────────────────────
      Week 1   Week 2   Week 3   Week 4

Comparing Scans

Side-by-Side Comparison

Compare any two scans:

Select a scan from history
Click Compare
Select another scan
View differences highlighted

┌─────────────────────────────────────────────────────────────────┐
│  SCAN COMPARISON                                                │
│  Jan 8 vs Jan 15                                               │
│                                                                 │
│  Metric          Jan 8        Jan 15       Change              │
│  ─────────────────────────────────────────────────────         │
│  Performance     68           72           +4  ↑               │
│  LCP             3.2s         2.8s         -0.4s ↑             │
│  CLS             0.08         0.05         -0.03 ↑             │
│  INP             320ms        280ms        -40ms ↑             │
│                                                                 │
│  Summary: Overall improvement after image optimization         │
└─────────────────────────────────────────────────────────────────┘

Regression Detection

Automatic Alerts

PeerScripts monitors for performance regressions:

Score drops > 10 points
Core Web Vitals move from Good to Needs Improvement/Poor
New failed audits appear

Correlation with Changes

When a regression is detected, PeerScripts checks for related changes:

Theme file modifications
New app installations
Product/content changes

Export & Sharing

Export Options

PDF Report: Formatted report for stakeholders
JSON Data: Raw data for analysis
CSV: Spreadsheet-friendly format

Sharing

Copy shareable link
Email report directly
Download for offline viewing

Best Practices

Testing Frequency

Scenario	Recommended Frequency
Active development	After each deployment
Stable store	Weekly
Pre-campaign	Before major sales
After theme changes	Immediately

Optimization Priority

Fix Poor metrics first (red scores)
Address high-impact recommendations
Improve Needs Improvement metrics (yellow scores)
Maintain Good metrics

Common Quick Wins

Optimization	Typical Improvement
Compress images	0.5-2s LCP reduction
Defer non-critical JS	0.3-1s improvement
Preload key resources	0.2-0.5s improvement
Enable lazy loading	Reduced initial load
Use modern image formats	20-30% smaller images

Integration

Automated Scans

Set up scheduled scans:

Go to Settings > Automation
Enable Scheduled Lighthouse Scans
Choose frequency (daily, weekly, monthly)
Select device types to test

Webhooks

Receive scan notifications:

{
  "event": "lighthouse_scan_completed",
  "performance_score": 72,
  "lcp": 2.8,
  "cls": 0.05,
  "inp": 280,
  "regression_detected": false
}

Troubleshooting

Scan Fails

Check if your store is accessible (not password protected)
Verify the URL is correct
Try again—occasional failures happen

Inconsistent Scores

Normal variation of ±5 points is expected
Test at consistent times to reduce variation
Use average of multiple scans for accurate baseline

Very Low Scores

Focus on top recommendations first
Consider theme performance optimization
Review installed apps for performance impact

Related Features

Theme Intelligence - Find code causing performance issues
App Intelligence - Identify apps impacting performance
Action Center - Bulk performance fixes