Performance of Web Apps Saved to Home Screen Hampered in iOS 4.3

The Register reports that performance of web apps saved to the home screen on iOS devices running iOS 4.3 is significantly crippled compared to those loaded directly through the Safari browser for iOS, although it is unclear if the issue is caused by bugs or a conscious move by Apple to favor App Store apps over web app experiences.

If a web app is run from the iOS 4.3 home screen - in other words, if it is saved to the screen alongside local apps downloaded from the Apple App Store - it runs roughly two to two and a half times slower than it does in the browser, according to various tests. It appears that whereas Apple has updated the iOS 4.3 Safari browser with its high-speed Nitro JavaScript engine, Nitro is not used when web apps are launched from the home screen.

"Essentially, there are two different JavaScript engines," says Alex Kessinger, a mobile application developer and blogger who has focused on building web-standards-based apps for the iPhone. "They're not using the new JavaScript engine with applications that launch from the home screen."

In addition, web apps saved to the home screen are unable to take advantage of HTML5 web caching capabilities, preventing them from running while offline.

114228 sunspider ios 4 3 500
Sunspider loaded in Safari (left) and as home screen web app (right)

One example given in the article is the Sunspider JavaScript benchmarking test, which was demonstrated running in 4047 ms when loaded within Safari but taking 10747 ms when loaded as a web app from the home screen.

The report notes that developers have filed multiple bug reports with Apple regarding the issues, with Apple apparently aware of at least some of the limitations currently being experienced with web apps saved to the home screen. Apple has reportedly acknowledged, however, that at least some of the issues, including ones related to the use of lower-quality synchronous mode rendering for home screen web apps as opposed to asynchronous mode used for content loaded directly in Safari, are not scheduled to be addressed by the company.

Related Roundup: iPad
Buyer's Guide: iPad (Neutral)
Related Forums: iPhone, iPad

Popular Stories

iPhone 16 Mock Header With Dynamic Island

Skipping the iPhone 15 Pro? Here's What's Rumored for iPhone 16 Pro

Friday September 22, 2023 9:29 am PDT by
Are you skipping the iPhone 15 Pro and waiting another year to upgrade? If so, we already have some iPhone 16 Pro rumors for you. Below, we recap new features rumored for the iPhone 16 Pro models so far:Larger displays: The iPhone 16 Pro and iPhone 16 Pro Max will be equipped with larger 6.3-inch and 6.9-inch displays, respectively, according to Ross Young, CEO of Display Supply Chain...
Update Your iPhone 15 to iOS 17

Warning: Update Your iPhone 15 to iOS 17.0.2 Before Transferring Data From Another iPhone

Friday September 22, 2023 6:36 am PDT by
If you are unboxing an iPhone 15, iPhone 15 Plus, iPhone 15 Pro, or iPhone 15 Pro Max today, make sure to update the device to iOS 17.0.2 before transferring data to the device from another iPhone, or else you might encounter issues. iOS 17.0.2 is only available for the iPhone 15 lineup. Apple says the update fixes an issue that may prevent transferring data directly from another iPhone...
iOS 17

Apple Releases iOS 17.0.1 and iPadOS 17.0.1 With Bug Fixes, Plus iOS 17.0.2 for iPhone 15 Models

Thursday September 21, 2023 10:28 am PDT by
Apple today released iOS 17.0.1 and iPadOS 17.0.1 updates for the iPhone and the iPad, adding bug fixes to the new software. The iOS 17.0.1 and iPadOS 17.0.1 updates come just a few days after Apple launched iOS 17 and iPadOS 17. The software, which is build 21A340, can be downloaded on eligible iPhones and iPads over-the-air by going to Settings > General > Software Update. There is a...
Apple Watch Ultra 2 double tap gesture 230912

watchOS 10.1 to Enable Apple Watch's New 'Double Tap' Gesture

Thursday September 21, 2023 12:52 pm PDT by
The new Double Tap gesture for the Apple Watch Series 9 and the Apple Watch Ultra 2 will be enabled starting with watchOS 10.1, according to Marques Brownlee, host of the popular tech-focused YouTube channel MKBHD. The first beta of watchOS 10.1 will likely be available by next week, and Apple announced that the software update will be released next month. Brownlee shared his impressions...