Looking at the iPhone 7, iPhone 8, iPhone X, and iPhone XS side by side shows one of the most important periods in the evolution of the iPhone. Apple went from the familiar home-button design of the iPhone 7 to the nearly all-screen iPhone X in only a year, then used the iPhone XS to significantly improve the technology inside that new design.

At first glance, some of these phones can seem very similar. The iPhone 7 and iPhone 8 look almost identical from the front, while the iPhone X and iPhone XS are extremely difficult to tell apart visually. Internally, however, there are much bigger differences.

iPhone 7, 8, X and XS at a Glance

Feature	iPhone 7	iPhone 8	iPhone X	iPhone XS
Release year	2016	2017	2017	2018
Display	4.7-inch LCD	4.7-inch LCD	5.8-inch OLED	5.8-inch OLED
Resolution	1334 × 750	1334 × 750	2436 × 1125	2436 × 1125
Home button	Yes	Yes	No	No
Authentication	Touch ID	Touch ID	Face ID	Face ID
Processor	A10 Fusion	A11 Bionic	A11 Bionic	A12 Bionic
Rear cameras	Single 12 MP	Single 12 MP	Dual 12 MP	Improved dual 12 MP
Optical zoom	No	No	2x telephoto	2x telephoto
Portrait Mode rear camera	No	No	Yes	Yes, improved
Wireless charging	No	Yes	Yes	Yes
Back material	Aluminum	Glass	Glass	Glass
Water resistance	IP67	IP67	IP67	IP68
Maximum storage	256 GB	256 GB	256 GB	512 GB
4K video	Up to 30 fps	Up to 60 fps	Up to 60 fps	Up to 60 fps
Dual SIM	No	No	No	Yes, in supported configurations

iPhone 7: The Last of the Classic Aluminum iPhones

Released in 2016, the iPhone 7 represents the older style of iPhone design. It has a 4.7-inch LCD display surrounded by relatively large bezels, with Apple’s familiar circular home button underneath.

The home button also contains Touch ID, allowing the phone to be unlocked with a fingerprint.

Inside is Apple’s A10 Fusion processor. It was fast for its time, but it predates the Neural Engine technology that became increasingly important in later iPhones.

The iPhone 7 uses a single 12-megapixel rear camera. It can record 4K video at up to 30 frames per second, but the standard iPhone 7 does not have the telephoto camera or rear-camera Portrait Mode found on later premium iPhones.

Its aluminum back also means that it does not support wireless charging.

The iPhone 7 was therefore the end of an era in several ways. Apple was about to move toward glass construction, wireless charging, machine-learning hardware, OLED displays, and eventually a completely buttonless front design.

iPhone 7 to iPhone 8: A Smaller Upgrade Than the Name Suggests

The iPhone 8 arrived in 2017 and looks very similar to the iPhone 7 from the front. It retains the 4.7-inch LCD display, large bezels, home button, and Touch ID.

The changes become more obvious when the phone is turned around.

Apple replaced the iPhone 7’s aluminum back with glass. One major reason for doing this was the addition of Qi wireless charging.

That means the iPhone 8 can simply be placed on a compatible wireless charger, something the iPhone 7 cannot do.

The processor also received a substantial upgrade. The A10 Fusion was replaced by the A11 Bionic.

The A11 was important because it introduced Apple’s first Neural Engine, dedicated hardware designed to accelerate certain machine-learning tasks.

Video capabilities also improved. While the iPhone 7 records 4K video at up to 30 fps, the iPhone 8 can record 4K at up to 60 fps.

However, the standard iPhone 8 still has only one rear camera. It does not provide the dual-camera system found on the iPhone X.

So the move from iPhone 7 to iPhone 8 was meaningful, particularly because of the A11 chip and wireless charging, but it was not a dramatic redesign.

iPhone 8 to iPhone X: The Huge Change

The iPhone X, pronounced “iPhone ten,” was also released in 2017, but it represented a completely different direction for the iPhone.

This was where Apple removed the traditional home button.

Instead of Touch ID, the iPhone X introduced Face ID. The TrueDepth camera system at the top of the display creates depth information about the user’s face and uses it for authentication.

Removing the home button also allowed Apple to dramatically increase the amount of screen on the front of the phone.

The iPhone 8 has a 4.7-inch LCD display with large areas above and below it. The iPhone X has a 5.8-inch OLED display that stretches much closer to the edges of the device.

OLED technology also gives the X much deeper blacks and significantly higher contrast than the LCD panel used in the iPhone 7 and iPhone 8.

Despite having a larger display, the iPhone X itself is not dramatically larger than an iPhone 8 because much more of its front surface is occupied by the screen.

The iPhone X Camera Was Another Major Upgrade

The iPhone X also moved to a dual 12-megapixel rear-camera system.

One camera provides the standard wide view, while the second is a telephoto camera. This gives the X 2x optical telephoto capability and enables rear-camera Portrait Mode.

Portrait Mode uses depth information to separate the subject from the background and simulate the shallow depth of field associated with larger cameras.

This makes the difference between the iPhone 8 and iPhone X much greater than simply comparing their processors. They actually use the same A11 Bionic generation, but the X gives you a very different display, authentication system, physical design, and camera system.

In simple terms, the iPhone 7 to iPhone 8 transition was an evolution. The iPhone 8 to iPhone X transition was a redesign.

Then Came the iPhone XS

The iPhone XS arrived in 2018.

This is where comparisons can become misleading.

Put an iPhone X and iPhone XS next to each other and they look almost identical. Both have a 5.8-inch OLED display, Face ID, a glass back, wireless charging, a stainless-steel frame, and vertically arranged dual rear cameras.

Because the design barely changed, the XS is sometimes described as little more than a faster iPhone X.

That misses many of its improvements.

The XS was primarily an internal upgrade, and several of those internal changes were significant.

A11 Bionic vs A12 Bionic

The iPhone X uses the A11 Bionic, while the iPhone XS uses the A12 Bionic.

The A12 was Apple’s first commercially released iPhone chip manufactured using a 7-nanometer process.

Apple said its two high-performance CPU cores could be up to 15 percent faster than those in the A11, while the four efficiency cores could use up to 50 percent less power. Its graphics processor could also deliver up to 50 percent higher graphics performance.

Those are important improvements, but the Neural Engine changed even more dramatically.

The A11’s Neural Engine could perform roughly 600 billion operations per second.

Apple rated the next-generation Neural Engine inside the A12 at up to 5 trillion operations per second.

That is more than eight times the theoretical Neural Engine throughput.

The A12’s Neural Engine could also be used more broadly by software through Apple’s Core ML technology. This mattered increasingly as photography, augmented reality, facial analysis, and other features began relying more heavily on machine learning.

So describing the XS simply as an iPhone X with a slightly faster processor understates what changed inside the chip.

The XS Camera Looks the Same on Paper, but It Isn’t

This is one of the most easily overlooked differences between the iPhone X and XS.

Both phones are commonly described as having dual 12-megapixel rear cameras. Looking only at megapixel counts makes them appear nearly identical.

They are not.

Apple equipped the XS with an updated imaging system that included a faster sensor with larger and deeper pixels on its wide camera.

That allowed the camera to capture more useful light and data.

The A12 also gave the XS substantially more computational power for processing photographs.

The result was not necessarily a dramatic increase in resolution, but a significant change in how the phone produced each image.

Smart HDR Arrived With the XS

One of the most important camera features introduced with the XS was Smart HDR.

The iPhone X already supported HDR photography, but Smart HDR made much heavier use of Apple’s image signal processor, sensors, and computational photography.

Rather than relying on a relatively simple exposure combination, the XS could rapidly capture and analyze multiple frames and use information from them to create a final photograph.

This could improve detail in bright highlights and dark shadows, especially in difficult lighting.

It represents an important change in smartphone photography: image quality was increasingly determined not merely by the physical camera hardware but by the processing performed immediately after the shutter button was pressed.

Portrait Mode Became More Adjustable

Both the iPhone X and iPhone XS can take Portrait Mode photographs, but the XS added another useful feature: Depth Control.

Depth Control allows the user to adjust the simulated depth of field in a Portrait Mode photograph.

In practical terms, that means the apparent amount of background blur can be changed rather than simply accepting the effect originally chosen by the phone.

The XS also benefited from improved depth segmentation and computational processing.

It is another example of why simply comparing “12 MP versus 12 MP” does not accurately describe the camera improvements.

Better Video Recording

The iPhone X and XS can both record 4K video at up to 60 fps, so a basic specification table makes them look equal.

There are additional differences.

The XS introduced extended dynamic range for video at up to 30 fps, helping it retain more information in difficult lighting situations.

It also introduced stereo audio recording for video.

That is a relatively small specification that can make a noticeable difference when watching recorded footage. Video from the XS can provide a stronger sense of direction and space than mono audio.

The XS uses multiple built-in microphones as part of this recording system.

Improved Front Camera Video

The front-facing camera system also received improvements.

The iPhone XS can record 1080p front-camera video at either 30 or 60 frames per second.

The TrueDepth camera and A12 processor also work together for Face ID, Portrait Mode selfies, Animoji, Memoji, and other depth-aware features.

Again, much of the improvement came from processing rather than simply increasing the camera’s megapixel count.

Face ID Became Faster

Both the iPhone X and XS use Apple’s TrueDepth camera system and Face ID rather than Touch ID.

However, the XS benefits from the faster Secure Enclave and improved algorithms associated with the A12 generation.

The result is quicker Face ID authentication under many conditions.

It is not a completely new Face ID system in the same way that moving from Touch ID to Face ID was, but it is a refinement users can notice during everyday use.

The XS Had Much Better Cellular Hardware

One of the more overlooked upgrades involves cellular connectivity.

The iPhone X supports LTE Advanced, but the iPhone XS moved to Gigabit-class LTE and added technologies including 4×4 MIMO and Licensed Assisted Access.

Under the right network conditions, this could provide significantly higher cellular data performance.

The improvement depends heavily on the carrier, frequency bands, signal conditions, and network infrastructure, so not every user would experience the same increase.

Still, the modem and antenna capabilities were an important internal difference between the two generations.

Dual SIM Arrived on the iPhone XS Generation

The XS generation also introduced Dual SIM functionality on iPhone.

In many markets, this used a physical nano-SIM together with an eSIM.

This made it possible, for example, to keep personal and business phone numbers on the same device or maintain a primary number while using another mobile plan when traveling.

Some regional versions used different SIM arrangements, so exact functionality varies by model and country.

Nevertheless, Dual SIM was a significant capability introduced with this generation and is often omitted from simple X-versus-XS comparisons.

Water Resistance Improved

The iPhone 7, iPhone 8, and iPhone X carry an IP67 water- and dust-resistance rating.

The iPhone XS increased that rating to IP68.

The XS was tested for immersion at a greater depth than the iPhone X under Apple’s specified laboratory conditions.

It is important to remember that water resistance is not the same as waterproofing. Resistance can also decrease as a phone ages or experiences physical wear.

Still, moving from IP67 to IP68 was a genuine hardware improvement.

The XS Offered Twice the Maximum Storage

Another easy-to-overlook difference is storage capacity.

The iPhone X was available with up to 256 GB of internal storage.

The iPhone XS added a 512 GB configuration.

For users recording large amounts of 4K video, carrying extensive photo libraries, downloading media, or using large applications and games, doubling the maximum capacity was substantial.

The Speakers Were Improved

The XS also received improvements to its stereo speaker system.

Apple described the XS as providing wider stereo sound.

This does not appear nearly as impressive on a specification sheet as an OLED display or new processor, but it contributes to the experience when watching movies, playing games, listening to music, or using the phone without headphones.

It is another example of the XS receiving numerous smaller refinements that are easy to miss when looking only at the exterior.

Battery Life Was Slightly Better

Apple rated the iPhone XS for approximately 30 minutes longer battery life than the iPhone X under its comparison methodology.

That is not an enormous increase, but it is notable because the XS also offers more processing capability.

Part of this improvement came from the increased efficiency of the A12 Bionic architecture.

Battery condition matters enormously today, however. On used devices this old, the health and replacement history of the individual battery can matter much more than the original difference between the X and XS.

The XS Added a Gold Finish

The iPhone X was sold primarily in Silver and Space Gray.

The XS added Gold.

This obviously does not affect performance, but it is one of the easiest visual ways to identify certain XS models.

Otherwise, an iPhone X and XS can be remarkably difficult to distinguish from the front.

The Evolution From iPhone 7 to XS

Looking at all four models makes Apple’s progression much clearer.

iPhone 7 to iPhone 8

This was primarily an internal and materials upgrade.

You gained:

• The A11 Bionic processor
• Apple’s first-generation Neural Engine
• A glass back
• Qi wireless charging
• 4K video recording at up to 60 fps
• Improved camera processing

The overall appearance and method of using the phone remained familiar.

iPhone 8 to iPhone X

This was the dramatic transformation.

You gained:

• A 5.8-inch OLED display
• A nearly edge-to-edge screen
• Face ID
• The TrueDepth camera system
• Removal of the home button
• Gesture-based navigation
• A dual rear-camera system
• A telephoto camera
• Rear-camera Portrait Mode
• 2x optical telephoto capability
• A stainless-steel frame

This was effectively the beginning of the modern iPhone design.

iPhone X to iPhone XS

This upgrade was less visible but much deeper than it initially appeared.

You gained:

• The A12 Bionic processor
• A vastly more powerful Neural Engine
• Faster graphics
• Greater processing efficiency
• An improved rear-camera sensor
• Smart HDR
• Depth Control for Portrait Mode
• Improved computational photography
• Extended dynamic range for video
• Stereo audio recording for video
• Improved front-camera video
• Faster Face ID processing
• Gigabit-class LTE
• 4×4 MIMO
• Dual SIM support
• IP68 water resistance
• Up to 512 GB of storage
• Wider stereo speaker output
• Slightly improved battery life
• A Gold color option

Why the XS Is Easy to Underestimate

The iPhone XS is unusual because almost none of its biggest improvements are obvious when you first pick it up.

The jump from an iPhone 8 to an iPhone X is immediately visible. The screen is different, the home button disappears, Face ID replaces Touch ID, and the entire interaction model changes.

The XS does not have that advantage.

Its improvements happen mostly behind the scenes.

The camera takes advantage of a faster sensor and much more sophisticated computational photography. The processor contains a dramatically stronger Neural Engine. The cellular system is more advanced. Face ID processing is quicker. Video gets improved dynamic range and stereo recording. Water resistance increases. Storage can reach 512 GB.

Individually, some of these changes might seem minor. Taken together, they make the XS a considerably more advanced device internally than the nearly identical-looking iPhone X.

Final Comparison

The easiest way to understand these four generations is this:

iPhone 7 to iPhone 8: evolutionary upgrade.

The basic design stayed the same, but Apple added a faster processor, glass construction, wireless charging, and stronger video capabilities.

iPhone 8 to iPhone X: revolutionary redesign.

The home button disappeared, Face ID arrived, OLED replaced the traditional LCD design, bezels became dramatically smaller, and the dual-camera system brought telephoto photography and Portrait Mode.

iPhone X to iPhone XS: major internal refinement.

The appearance barely changed, but the A12 Bionic, dramatically more capable Neural Engine, improved camera sensor, Smart HDR, Depth Control, better video and audio recording, improved cellular connectivity, Dual SIM, stronger water resistance, increased storage, and numerous smaller refinements made the XS much more than an iPhone X with a faster processor.

That is why the iPhone XS is easy to overlook when comparing older iPhones. The iPhone X created the design that defined the next several generations, while the XS quietly made that design substantially more capable.