Existing users, 
The iPhone’s poor JavaScript performance
Posted 3 July 2007 @ 3pm in Development, Troubleshooting
No one expected the iPhone to deliver desktop-class performance with regard to Web-based applications, but JavaScript speed on the iPhone is downright sluggish in most respects — a frustrating fact given that AJAX is the only current method for building dynamic third-party applications for the iPhone.
Celtic Kane online offers a Javascript benchmark that tests various Javascript functions: Try/Catch with errors, Layer movement, Random number engine, Math engine, DOM speed, Array functions String functions and Ajax declaration. In our informal tests, a MacBook Pro running at 1.83GHz with Mac OS X 10.4.10 and the Safari 3.0.2 beta delivered test times of ~300 ms on average. Our in-house iPhones, however, delivered test times in excess of 9000 ms on average.
Of course, benchmarks are benchmarks, so we tested a few of the most intensive AJAX Web apps in existence: games. While they all delivered smooth play on our MacBook Pro, they were virtually unplayable on the iPhone, exhibiting lazy movement and slow response to cursor input. Among the games we tried:
- BunnyHunt (extremely sluggish movement)
- Vox Imperium (crashed the iPhone browser)
- Super Maryo World (unplayable on the iPhone because of the lack of a user-triggered keyboard, but demo is extremely slow)
The Meebo Web-based instant messaging service, which now works to some extent with the iPhone, is also very slow to respond.
Given the poor JavaScript showing, we have to wonder if Flash (or Flash Lite) wasn’t ommited due to performance concerns.
Feedback? info@iphoneatlas.com.
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4 Comments
Posted by mdh
3 July 2007 @ 3pm
I’m wondering if anyone with an iPhone would be willing to visit: http://www.daytrotter.com/iPhone and let me know if the songs on that page can be played.
Posted by zahadum
4 July 2007 @ 8am
it may seem obvious - but please indicate if this test was done on wifi or edge network!?
Posted by jmock
5 July 2007 @ 11am
@mdh: Yep. The page is a little slow to load, but the songs do play (they load in the QT player on the phone).
Posted by cabo1
5 August 2007 @ 5am
Just so you don’t think the iPhone is slow on Celtic Kane’s benchmark: Nokia’s E90 clocks in at 15200 to 15300 ms. (I briefly thought Symbian had crashed :-)