An iPhone 15 will install iOS 27 on September 14, but it will not run Apple Intelligence or Siri AI: Apple’s iOS 27 page limits those to iPhone 15 Pro, 15 Pro Max and iPhone 16 or later. That one line is the strongest reason to move to an iPhone 18 Pro, ahead of the 16 extra rated hours of video playback, the 4x telephoto, the 120Hz display and USB 3.
The iPhone 15 launched on September 22, 2023 at $799, according to Apple’s press release, and it was the first iPhone with USB-C. Apple no longer sells it; its Store page lists a trade-in estimate of up to $305. The 18 Pro is $1,199 for 256GB, with pre-orders on September 12 and availability on September 18.
Key facts
| Spec | iPhone 15 | iPhone 18 Pro |
|---|---|---|
| Chip | A16 Bionic | A20 Pro (2nm), 7-core GPU, dual 16-core Neural Engine |
| Apple Intelligence | No | Yes, including Siri AI beta |
| Display | 6.1-inch OLED, 2556 x 1179, 460 ppi, no ProMotion | 6.3-inch OLED, 2622 x 1206, 460 ppi, ProMotion 120Hz, Always-On |
| Video playback | Up to 20 hours | Up to 36 hours |
| USB-C | USB 2, 480 Mb/s | USB 3, up to 10 Gb/s |
| MagSafe / Qi | 15W / Qi 7.5W | 25W / Qi2 25W |
| Weight | 171 g | 211 g |
| Launch price | $799 (128GB) | $1,199 (256GB) |
Software: iOS 27 yes, Apple Intelligence no
Apple’s iOS 27 page lists compatibility as iPhone 12 and later, so the 15 gets the September 14 update with Safari’s automatic tab organization and Notify Me, richer VoiceOver descriptions, the Home app changes and the redesigned Health features. It does not get the Apple Intelligence layer: no Siri AI, no Image Playground, no Clean Up, no Siri mode in the Camera app. Our iOS 27 release guide has the full feature list.
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The 18 Pro ships with iOS 27 and the dual 16-core Neural Engine Apple built for that layer. If Apple Intelligence is the reason you are upgrading, note that a cheaper iPhone 16 or 17 also qualifies; the Pro’s case rests on the hardware below.
Cameras: a 2x crop against three 48MP sensors
| Camera | iPhone 15 | iPhone 18 Pro |
|---|---|---|
| Main | 48MP, 26 mm, f/1.6, sensor-shift OIS | 48MP Fusion, 24 mm, variable f/1.48, f/1.8, f/2.8, f/4.0 |
| Ultra Wide | 12MP, 13 mm, f/2.4 | 48MP, 13 mm, f/2.2, 120-degree field of view |
| Telephoto | 12MP 2x crop, 52 mm, f/1.6 | 48MP 4x, 100 mm, f/2.8, plus 12MP 8x crop at 200 mm |
| Zoom range | 2x in, 2x out | 8x optical-quality in, 2x out (16x range) |
| Front | 12MP, f/1.9 | 18MP Center Stage, f/1.9 |
The 15 was the first standard iPhone with a 48MP main sensor, and that sensor is what gives it a 2x crop at 52 mm. The 18 Pro adds a physical 100 mm telephoto, crops it to 200 mm, upgrades the Ultra Wide from 12MP at f/2.4 to 48MP at f/2.2, and replaces the fixed f/1.6 with a four-stop variable aperture. The 18 Pro camera explainer walks through when each stop matters.
Battery, charging and USB-C speed
Apple rates the iPhone 15 at up to 20 hours of video playback, 16 hours streamed and 80 hours of audio. The 18 Pro is rated at 36 hours of video, 33 hours streamed and 24 hours of typical use, a metric Apple did not publish for the 15.
Both phones use USB-C, but the 15’s port runs at USB 2 speeds of 480 Mb/s while the 18 Pro’s is USB 3 at up to 10 Gb/s. Charging follows the same pattern: the 15 reaches 50 percent in about 30 minutes with a 20W or higher adapter, the 18 Pro in about 15 minutes with a 60W adapter. Wireless moves from 15W MagSafe and 7.5W Qi to 25W MagSafe and 25W Qi2. The 18 Pro battery guide has the 35W MagSafe figure and the five-minute top-up.
Chip, build and price
The A16 Bionic in the 15 is a 2022 chip that Apple reused in 2023. The A20 Pro is Apple’s first 2nm chip; Apple states its gains against the A19 Pro, so there is no Apple percentage for the four-generation gap. The 18 Pro adds Wi-Fi 7, Bluetooth 6, the C2 modem with mmWave 5G in the US and dual eSIM that stores eight or more profiles.
The 15 is 171 g with an aluminum frame, Ceramic Shield front and color-infused glass back; the 18 Pro is 211 g with an aluminum unibody, Ceramic Shield 2 front and Ceramic Shield back, and it is IP68 rated to 6 meters for 30 minutes. Storage moves from a 128GB to 512GB range to 256GB to 2TB. On Apple’s US Store page the 18 Pro is $1,199, $1,399, $1,799 and $2,399 by tier, or $49.95 a month over 24 months. With Apple’s up to $305 trade-in for the 15, the base 18 Pro comes to $894 at best.
What Apple has not said
- Apple has not published a performance comparison between the A20 Pro and the A16 Bionic.
- Apple’s spec sheet for the iPhone 15 lists no ProMotion and states no refresh rate.
- Apple has not published a typical-use battery rating for the iPhone 15, or an audio figure for the 18 Pro in our sources.
- The $305 trade-in estimate is an upper bound; Apple has not published values by condition.
iPhone 18 Pro pre-orders open Saturday, September 12 at 5 a.m. PT, with availability on Friday, September 18 from $1,199. iOS 27 reaches the iPhone 15 on Monday, September 14, without Apple Intelligence.
