Page 4: JavaScript Heavy Test
Test Focus: This page loads 3 JavaScript files (~205KB total) to test script parsing, compilation, and execution time differences between Safari and Chrome.
Capturing performance metrics
JavaScript Performance Test
Script Loading Status:
- storage.js: Loading...
- heavy.js: Loading...
- perf-monitor.js: Loading...
JavaScript Computation Test:
Running heavy computation...
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About This Test
This page tests JavaScript loading, parsing, and execution performance. Large JavaScript files can significantly impact page load time, especially on mobile devices.
What to Look For
- DOM Interactive Time: May be delayed if scripts block parsing
- Script Parse Time: Different JavaScript engines (Safari's JavaScriptCore vs Chrome's V8)
- Execution Performance: Computational tasks may run at different speeds
- Resource Timing: Check console for individual script load times
JavaScript Engines
Safari uses JavaScriptCore (also called Nitro), while Chrome uses V8. While both are highly optimized, they may have different performance characteristics for parsing and executing large scripts.