Performance by Device

Understand how your website performs across different devices, browsers, and operating systems.

Device Overview

Performance by Device Type

Device Type Performance (Last 30 Days)

               Load Time   LCP      INP      CLS
Desktop        1.8s        1.9s     120ms    0.04
Mobile         3.2s        2.8s     210ms    0.12
Tablet         2.4s        2.3s     160ms    0.08

Mobile typically shows 40-60% slower performance due to:

• Slower processors
• Cellular networks
• Smaller screens (more scrolling)

Device Distribution

Traffic by Device

Desktop   ████████████████████████████████  58%
Mobile    ██████████████████████████        38%
Tablet    ████                               4%

Browser Analysis

Performance by Browser

Browser Performance

Browser       Version    Load Time   LCP      Users
Chrome        120        1.9s        2.0s     45%
Safari        17         2.1s        2.2s     22%
Firefox       121        2.0s        2.1s     12%
Edge          120        1.9s        2.0s     11%
Samsung Int.  23         3.5s        3.2s     6%
Other         -          2.8s        2.6s     4%

Browser-Specific Issues

Browser	Common Issues
Safari	Different scroll behavior, WebP support varies
Firefox	Some CSS differences
Samsung	Often older engine, slower hardware
IE/Edge Legacy	Limited modern feature support

Version Distribution

Chrome Versions

120 (latest)  ████████████████████████  62%
119           ████████████              25%
118           ████                       8%
< 118         ██                         5%

Older versions may have:

• Missing optimizations
• Security issues
• Compatibility problems

Operating System Analysis

Performance by OS

Operating System Performance

OS              Load Time   LCP      Traffic
Windows 11      1.8s        1.9s     35%
macOS           1.7s        1.8s     18%
iOS             2.9s        2.6s     22%
Android         3.4s        3.0s     20%
Windows 10      2.0s        2.1s     4%
Linux           1.6s        1.7s     1%

Mobile OS Comparison

Mobile Performance

               Load Time   LCP      INP      CLS
iOS            2.9s        2.6s     180ms    0.08
Android        3.4s        3.0s     240ms    0.14

iOS often performs better due to:

• Consistent hardware
• Safari optimizations
• Faster average devices

Screen Size Analysis

Performance by Viewport

Viewport Width Performance

Width        Load Time   LCP      CLS      Traffic
< 480px      3.4s        3.0s     0.14     32%
480-768px    3.0s        2.7s     0.10     12%
768-1024px   2.4s        2.3s     0.06     8%
1024-1440px  1.9s        2.0s     0.04     28%
> 1440px     1.8s        1.9s     0.03     20%

Responsive Issues

Small screens may have:

• More layout shifts (CLS)
• Different content loading
• Touch vs click interactions

Connection Type Analysis

Performance by Network

Connection Type Performance

Connection    Load Time   TTFB     Traffic
WiFi          2.0s        150ms    55%
4G            2.8s        220ms    35%
3G            5.2s        480ms    8%
2G            12.5s       1.2s     1%
Offline       -           -        1%

Network Conditions

Connection	Typical Bandwidth	Latency
WiFi/Cable	10-100+ Mbps	20-50ms
4G	5-50 Mbps	50-100ms
3G	1-10 Mbps	100-300ms
2G	50-250 Kbps	300-1000ms

Optimizing for Slow Networks

• Reduce JavaScript payload
• Optimize images aggressively
• Implement service workers
• Use resource hints

CPU Performance

Performance by Device Power

Device Power Performance

Power Level    Load Time   INP      Traffic
High-end       1.6s        90ms     25%
Mid-range      2.4s        160ms    45%
Low-end        4.2s        340ms    30%

Detecting Slow Devices

Zenovay estimates device power from:

• Device model (when available)
• JavaScript execution time
• Memory constraints
• CPU core count

Geographic Impact

Regional Performance

Performance by Region

Region           Load Time   TTFB     Users
North America    1.9s        120ms    40%
Europe           2.1s        150ms    30%
Asia Pacific     2.8s        280ms    20%
South America    3.2s        350ms    6%
Other            3.5s        400ms    4%

CDN Impact

Compare with/without CDN:

CDN Impact on TTFB

Region          Without CDN    With CDN    Improvement
North America   120ms          95ms        21%
Europe          280ms          110ms       61%
Asia Pacific    450ms          140ms       69%

Segmentation & Filtering

Custom Segments

Create device-specific segments:

1. Go to Performance → Segments
2. Create segment:
   • Name: "Slow Mobile"
   • Device: Mobile
   • Connection: 3G or slower
   • Load Time: > 5s

Compare Segments

Side-by-side comparison:

Desktop vs Mobile Comparison

Metric          Desktop    Mobile     Diff
Load Time       1.8s       3.2s       +78%
LCP             1.9s       2.8s       +47%
INP             120ms      210ms      +75%
CLS             0.04       0.12       +200%
Bounce Rate     32%        48%        +50%

Alerting by Device

Device-Specific Alerts

Set alerts for specific conditions:

1. Go to Settings → Alerts
2. Create alert:
   • Name: "Mobile Performance Degraded"
   • Condition: Mobile LCP > 3s
   • Compare: vs last week
   • Notify: Slack, Email

Alert Examples

Alert	Condition
Mobile slowdown	Mobile load time increases 20%
Browser issue	Chrome LCP spikes
New device type	Unusual device appears

Optimization Strategies

Mobile-First Optimization

Priority for Mobile

1. Reduce JavaScript (biggest impact)
2. Optimize images for mobile
3. Minimize layout shifts
4. Improve tap target sizes
5. Test on real devices

Device-Specific Serving

<!-- Responsive images -->
<picture>
  <source
    srcset="image-mobile.webp"
    media="(max-width: 768px)"
  >
  <source
    srcset="image-desktop.webp"
    media="(min-width: 769px)"
  >
  <img src="image-fallback.jpg" alt="Description">
</picture>

Progressive Enhancement

// Feature detection
if ('IntersectionObserver' in window) {
  // Use modern lazy loading
} else {
  // Fall back to simpler approach
}

Reporting

Device Performance Report

Generate device-focused reports:

1. Go to Reports → Create Report
2. Select "Device Performance"
3. Choose metrics:
   • Performance by device type
   • Browser breakdown
   • Network conditions
4. Schedule delivery

Executive Summary

Device Performance Summary - January 2025

Key Metrics:
• Mobile load time improved 15% from December
• Safari users showing 8% higher CLS
• 4G performance stable

Recommendations:
• Continue mobile optimization
• Investigate Safari layout issues
• Consider lighter experience for 3G

Best Practices

Testing Strategy

1. Real device testing: Use actual devices
2. Device lab: Multiple OS/browser combinations
3. Throttling: Test slow network conditions
4. Synthetic + RUM: Lab and real-user data

Prioritization

Focus on:

1. Largest device segment (usually mobile)
2. Slowest devices in major segment
3. Highest-impact issues
4. Quick wins first

Performance Budgets by Device

Performance Budgets

Metric      Desktop    Mobile
LCP         < 2.0s     < 2.5s
INP         < 150ms    < 200ms
CLS         < 0.05     < 0.1
Load Time   < 2.0s     < 3.0s

Troubleshooting

No Device Data

Check:

• Script collecting user agent
• Not being blocked by privacy tools
• Sufficient traffic sample

Unexpected Device Types

Review:

• Bot traffic filtering
• Device detection accuracy
• New device categories

Large Performance Gaps

Investigate:

• Network-dependent resources
• Device-specific code paths
• Third-party impact

Next Steps

• Core Web Vitals
• Page Load Performance
• Performance Alerts