It’s been years since Jony Ive and Tim Cook stood on stage to introduce the phone that killed the home button. Honestly, looking back, we focus so much on the "notch" or the FaceID sensors that we forget the most practical thing about it. The size. Specifically, the length of an iPhone X was a radical departure from the "Plus" sized monsters that were dominating the market in 2017.
Apple nailed a sweet spot.
If you hold one today, it feels strangely dense. Tiny, almost. But back then? It was the "all-screen" future. Let’s get the raw numbers out of the way because that’s why you’re here. The length of an iPhone X is exactly 5.65 inches (143.6 mm). For context, it was significantly shorter than the iPhone 8 Plus, yet it had a larger screen. That’s the magic of losing the "chin" and "forehead" bezels.
The Physicality of 5.65 Inches
Height matters. When we talk about the length of an iPhone X, we are talking about vertical reachability. It’s that distance your thumb has to travel to pull down the Control Center.
At 143.6 mm, the device sat comfortably between the standard iPhone 8 and the massive 8 Plus. It was 70.9 mm wide and 7.7 mm thick. It weighed 174 grams. That weight is important because the stainless steel frame made it feel more premium than the aluminum 7 or 8.
You’ve probably noticed how phones just kept growing after this. The iPhone 15 Pro, for comparison, is roughly 146.6 mm long. It’s grown. Not by a mile, but enough that the original X feels like a "compact" phone by 2026 standards.
Why the Length of an iPhone X Dictated Design
Before the X, Apple was stuck. They had the 4.7-inch design and the 5.5-inch design. If you wanted a big screen, you had to carry a surfboard in your pocket. The length of an iPhone X solved the "pocketability" crisis.
By stretching the screen to a 19.5:9 aspect ratio, Apple could claim a 5.8-inch display diagonal. But don’t let that number fool you. Because the phone is narrower and the length of an iPhone X is shorter than an 8 Plus, you actually had less total screen area than the Plus models in some scenarios, specifically when watching 16:9 video. You got black bars. Or, you zoomed in and lost the top and bottom of the frame.
It was a trade-off.
The OLED panel was the first of its kind in an iPhone. Samsung manufactured it to Apple's specs. Because of the specific length of an iPhone X, the pixel density hit 458 ppi, which they dubbed "Super Retina." It looked incredible, but the ergonomics were the real winner. You could actually use it with one hand. Mostly.
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Reachability and the Notch
Even with a manageable length, reaching the top corners was a chore for some. Apple kept the "Reachability" gesture (swiping down on the bottom edge), but the gesture bar changed the game.
Think about the chassis. The stainless steel wasn't just for looks. It provided the structural rigidity needed because the length of an iPhone X was packed with two battery cells in an L-shape. They had to cram everything in. Logic boards were folded. Components were miniaturized. Every millimeter of that 143.6 mm height was utilized to its absolute limit.
Comparing the Length to Modern Iterations
It is wild to see how the "Goldilocks" size of the X became the blueprint. Let's look at the evolution of the length of an iPhone X compared to its successors:
- iPhone X: 143.6 mm
- iPhone 11 Pro: 144.0 mm
- iPhone 13 Pro: 146.7 mm
- iPhone 15: 147.6 mm
See the trend? We are slowly creeping upward. The "small" iPhone is getting longer. This makes the length of an iPhone X feel even more vintage and "correct" to people who hate the phablet trend.
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If you're buying a case today, don't assume an iPhone XS case fits perfectly. While the length of an iPhone X and the XS are identical, the camera bump on the XS is slightly—and I mean slightly—larger. It’s one of those annoying tech things where a millimeter ruins a $50 leather case.
Longevity and the "Hand Feel"
Is 5.65 inches still the "right" size?
Many enthusiasts argue yes. The length of an iPhone X allowed for a screen that felt expansive without stretching your denim pockets to the breaking point. If you go much shorter, like the iPhone 13 Mini (131.5 mm), the battery life usually tanks. If you go much longer, like the Pro Max models (160+ mm), you’re basically carrying a tablet.
The X was the pivot point.
What to Do if You’re Still Using One
If you are rocking an iPhone X in 2026, you’re likely feeling the age in the processor (the A11 Bionic), not the size. The length of an iPhone X is still arguably the most ergonomic design Apple ever shipped.
If you’re looking to upgrade but love this specific footprint:
- Check the iPhone 13 Mini or 12 Mini. They are actually shorter than the X but offer similar performance. Note that they are discontinued, so you’ll be hitting the refurbished market.
- Measure your current grip. If your thumb struggles to reach the top-left corner on the 143.6 mm length of an iPhone X, do not buy a Plus or Max model. You will regret it within a week.
- Battery Replacement. Since the X is older, that L-shaped battery is likely at 70% capacity. Replacing it is cheaper than a new phone and keeps that perfect form factor alive.
The length of an iPhone X remains a benchmark for "one-handed" usability in the smartphone world. It proved that you didn't need a massive chassis to have a massive-feeling screen. It was 5.65 inches of pure disruption.
Actionable Next Steps:
- Verify your model: Flip the phone over or check Settings > General > About to ensure you have the A1865, A1901, or A1902 model before buying precision accessories.
- Case Shopping: Always search specifically for "iPhone X" rather than "iPhone X/XS" if you want a perfect fit for the camera cutout, as the XS dimensions shifted the lens position by less than 2mm.
- Ergonomic Check: If you find the 143.6 mm length causes hand strain, try a "PopSocket" or "MagSafe adapter" (via a sticker) to center the weight in your palm.