[14] Rumors of a drastic iPhone redesign began circulating around the time of iPhone 7 announcement in the third quarter of 2016,[15][16] and intensified when a HomePod firmware leak in July 2017 suggested that Apple would shortly release a phone with a nearly bezel-less design, lack of a physical home button, facial recognition, and other new features.

[38][39] Greg Joswiak, Apple's vice president of product marketing, told Tom's Guide that the OLED panels Apple used in the iPhone X had been engineered to avoid the over-saturation of colors that using OLED panels typically results in, having made color adjustments and subpixel-level refinements for crisp lines and round corners.

[35] The sides of the phone are composed of surgical-grade stainless steel to improve durability, and the front and back are made of glass.

[51][52] By default, the system will not work with eyes closed, in an effort to prevent unauthorized access but this requirement can be disabled in settings.

One is a 12-megapixel wide-angle camera with f/1.8 aperture, with support for face detection, high dynamic range and optical image stabilization.

[35] In tests conducted by MacRumors, the iPhone X's charging speeds varies significantly depending on what types of cables, powerbanks, adapters, or wireless chargers are used.

Apple published a "Human Interface Guidelines" document to explain areas of focus, and discouraged developers from attempting to mask or call special attention to any of the new changes.

[70][71][72] The traditional home button, found on all previous devices in the iPhone lineup, has been removed entirely, replaced by touch-based gestures.

However, the sensor housing "notch" at the top of the screen and the introduction of an all-new authentication method were polarizing for critics and consumers.

Face ID facial recognition was praised for its simple setup, but criticized for requiring direct eyes on the screen, though that option can be disabled within the system preferences.

[79][80] Chris Velazco of Engadget praised the display, writing that, in his experience, the sensor "notch" goes from being "weird at first" to not being noticeable due to action in videos usually happening in the center.

The build quality was given particular acclaim, being called "a beautifully made device" with the construction that "seamlessly" connects the front and back glass with the stainless-steel frame.

Velazco noted that the new gesture-based interaction takes time to get used to, particularly the Control Center being moved from the bottom to the top right of the display.

He criticized the repeated lack of a headphone jack, the device's fragility despite Apple's claims of durability, and the sensor notch, calling it "ugly".

[83] In a heavily negative review, Dennis Green of Business Insider significantly criticized the impossible one-handed use of iPhone X, writing that the new gestures to use the phone, such as swiping from the top down to access notifications and the Control Center, did not work when using the phone with only one hand due to not being able to reach the top.

[84] His review sparked outrage among Twitter users, many of whom used condescending tones, which Green reasoned as "I don't know whether the anger was directed toward me out of loyalty to Apple or to justify their own choice to spend $1,000 on a phone.

[87] United States Senator Al Franken asked Apple to provide more information on the security and privacy of Face ID a day after the announcement,[88] with Apple responding by highlighting the recent publication of a security white paper and knowledge base detailing answers.

[95] A week after iPhone X was released, Vietnamese security firm Bkav announced in a blog post that it had successfully created a $150 mask that tricked Face ID, though WIRED noted that Bkav's technique was more of a "proof-of-concept" rather than active exploitation risk, with the technique requiring a detailed measurement or digital scan of the iPhone owner's face, putting the real risk of danger only to targets of espionage and world leaders.

However, the overall idea of letting developers access sensitive facial information was still not satisfactorily handled, according to Jay Stanley, a senior policy analyst with the ACLU, with Stanley telling Reuters that "the privacy issues around of the use of very sophisticated facial recognition technology for unlocking the phone have been overblown.

[98][99] Much of the debate about the iPhone X has revolved around the design of the Face ID sensor housing, dubbed "notch" by the media, at the top of the display.

The Outline described it as "a visually disgusting element",[100] and The Verge posted a report focusing on public criticism and people mocking Apple's "odd design choice",[101] but not every reviewer was equally negative in their opinions.

AT&T announced within hours that the issue had been fixed on their end, and a spokesperson for the Verizon carrier told the media none of its customers were affected despite some reports of problems.

[106][107] In November 2017, iPhone X users reported on Reddit that the device's screen would become unresponsive after experiencing rapid temperature drops.

[112] Apple has been engaged in a legal battle with Qualcomm over allegedly anti-competitive practices and has been dual-sourcing cellular modem chips to reduce reliance on the semiconductor manufacturer.

[113][114] Professional measurement tests performed by wireless signal testing firm Cellular Insights indicated that, as in the previous-gen iPhone 7, Qualcomm's chips outperform Intel's in LTE download speeds, up to 67% faster in very weak signal conditions,[115][116] resulting in some sources recommending the purchase of an unlocked iPhone X or one bought through cellular carrier Verizon, in order to get the models featuring the faster Qualcomm modem.

[117] After releasing the iPhone X in Japan and China, customers experienced issues related to the phone's NFC while trying to access public transit smart card readers.