SquareTrade estimates that the iPhone 4's malfunction rate over a 12-month span was just 2.1%, meaning that slightly more than two phones out of every 100 will die during a year.
Motorola's Android smartphones, including Verizon's Droid and Droid X, are projected to fail at an estimated rate of 2.3%, while 3.7% of HTC's Android devices -- ranging from Evo to the Droid Incredible -- will give up the ghost in a 12-month stretch.
SquareTrade pegged the older iPhone 3GS' failure rate at 2.3%, the same as Motorola's handsets.
"The iPhone is still the most reliable smartphone around," said Vince Tseng, SquareTrade's director of marketing.
To come to that conclusion, SquareTrade analyzed four months of iPhone 4 warranty claims, eights months of Motorola and HTC data, then graphed a 12-month failure rate for all manufacturers based on the real-world curve for all smartphones.
SquareTrade also mined its claim data for Research in Motion's BlackBerry, and found that the company's hardware failed at a 6.3% annual rate, triple that of the iPhone 4 and almost double that of HTC.
All failure rates excluded claims for accidental damage, such as shattered screens caused by dropping a smartphone.
"As long as you're sticking with the iPhone, Motorola and HTC, you'll be fine," said Tseng. "Those are the most reliable smartphones around."
But what grabbed Tseng's attention was the major improvement in reliability since SquareTrade last examined its claim data in November 2008.
Then, BlackBerrys failed at a whopping 11.9% rate in each 12-month span, while 5.6% of Apple's iPhone 3G phones -- its newest at the time -- failed in the same period.
That means Apple improved its failure rate by 62% in the last two years, Tseng said, while RIM cut its dead-smartphone rate by 47%.
Tseng called the Apple and RIM improvements "pretty impressive."
But while Apple's iPhone 4 leads the reliability pack, it's the smartphone most likely to break during a year, according to SquareTrade's accidental damage claims.
"In accidental damage, it's exactly the reverse. By far, the iPhone 4 breaks the most frequently, although we're also seeing a lot of claims from Motorola and HTC owners," Tseng said.
More than one out of seven iPhone 4 owners, 13.8%, to be exact, will file an accidental damage claim with SquareTrade in a year, the highest rate of any smartphone. Motorola and HTC owners reported damage claims at the same 12.2% rate, but only 6.7% of BlackBerry users filed claims during the same period.
Tseng for the high claim rate of 's newest , and said he wasn't surprised that devices such as the Evo and Droid -- both which feature large glass displays, albeit only on the front -- also had higher than average rates.
To curb breakage, Apple should reconsider its decision to use glass rather than plastic. "If Apple would move back to the same design as the 3GS, I'm sure we'd see a corresponding drop in accidents," Tseng said.
The iPhone 3GS is significantly sturdier than the iPhone 4, Motorola or HTC devices, with a 12-month accidental damage rate of 9.4%.
When SquareTrade combined malfunction and accident rates, the field was much more level, the company said in the survey results, which were released today. The iPhone 4's total claim rate was 14.9% -- identical to HTC's but slightly higher than the 14.6% of Motorola.
SquareTrade's smartphone reliability report can be or .
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at or subscribe to . His e-mail address is .
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