What the Xi Phone Means
The term "Xi phone" refers to Apple's iPhone X, the tenth-anniversary smartphone released in 2017. The "X" in iPhone X is the Roman numeral for 10, marking a decade of iPhone innovation. When people search for "Xi phone," they are typically looking for information about this specific model, its design, features, and legacy within Apple's product lineup.
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Apple has used Roman numerals in its iPhone naming only twice: the iPhone X and the iPhone XS, XS Max, and XR followed in 2018, continuing the "X" family. Understanding the Xi phone requires knowing its place in this naming evolution and what it offered compared to predecessors and successors.
Launch and Design of the iPhone X
Apple introduced the iPhone X in November 2017 alongside the iPhone 8 and 8 Plus. It was priced as the premium flagship, starting at $999. The design eliminated the home button that had defined iPhones since the original 2007 model, replacing it with a nearly edge-to-edge 5.8-inch OLED display branded Super Retina HD.
The stainless steel frame and glass back gave the iPhone X a premium feel, and the device introduced Face ID as the primary biometric security method. The TrueDepth camera system projected infrared dots to map the face, enabling secure authentication and animated emoji called Animoji.
Key Features of the Xi Phone
The iPhone X packed several features that set it apart from the iPhone 8 lineup. The A11 Bionic chip delivered strong performance and energy efficiency, while the dual 12MP rear cameras offered portrait mode with depth-of-field effects and improved low-light photography.
Wireless charging arrived with the iPhone X using Qi-compatible pads, and the device supported fast charging for quicker battery replenishment. The software introduced a new gesture-based navigation system replacing the home button, with swipe-up actions to return home, switch apps, and access the Control Center.
Display and Battery
The 5.8-inch OLED display on the Xi phone offered HDR content support, true blacks, and a contrast ratio of 1,000,000 to 1. Battery life was comparable to the iPhone 8 Plus, providing roughly 13 hours of 3G talk time, though actual usage varied with screen brightness and network conditions.
Face ID and Security
Face ID replaced Touch ID as the primary unlock method. Apple claimed the system was one in a million for random strangers, though it worked less reliably with masks, sunglasses, or significant appearance changes. The Secure Enclave kept facial data encrypted on-device, a privacy detail that has remained consistent through subsequent iPhone models.
iPhone X in the Broader Lineup
The Xi phone sat at the top of Apple's 2017 hierarchy, but its "X" design language carried forward. The iPhone XS and XS Max in 2018 refined the concept with the A12 Bionic chip, while the iPhone XR offered a more affordable entry to the X-style design with an LCD screen and single camera.
As of 2025, the iPhone X is several generations old and no longer receives major iOS updates, though it still supports basic functionality for calls, messaging, and web browsing. Its legacy endures as the device that first established the modern iPhone design language Apple follows today.
Should You Buy a Xi Phone Today?
Buying a used or refurbished iPhone X in 2025 is a niche choice. The device lacks 5G support, the latest camera capabilities, and current software features. However, for users seeking a compact, lightweight iPhone for basic tasks or as a secondary device, the Xi phone can still perform reliably on Wi-Fi and cellular networks.
Those considering the purchase should check battery health, as aging batteries degrade performance and may need replacement. The device also lacks the Always-On Display and dynamic island features introduced in later models, which are now considered standard in newer iPhones.