OtterBox cases designed for the iPhone 18 Pro are already on sale at Best Buy and, according to the listing, they’re compatible with both the iPhone 17 Pro and iPhone 18 Pro. The claim surfaced when Bloomberg’s Mark Gurman posted a photo of the case on sale, though he remained cautious about the announcement, calling the timing “a little early.”
The cross-compatibility claim gains credibility from a second source when Astropad’s Matt Ronge, who makes anti-reflective screen protectors, reported that his suppliers are independently telling him the same thing. The alignment between two separate accessory manufacturers suggests Apple may indeed be maintaining identical dimensions across both Pro models, or at least within tolerances tight enough to allow existing cases to fit new phones.
Otterbox seems to think the iPhone 18 Pro will be able to fit inside of iPhone 17 Pro cases and vice versa. Also, Best Buy is already putting these on shelves. A little early. pic.twitter.com/13l7OWj5wX
— Mark Gurman (@markgurman) August 19, 2026
The plausibility of cross-compatibility hinges on how much the iPhone 18 Pro actually differs from the iPhone 17 Pro. Leaked materials from an iPhone supplier indicated that the iPhone 18 Pro will be two millimeters thicker than its predecessors, which itself was already thicker than the iPhone 16 Pro at 8.25mm. The iPhone 17 Pro Max measures 8.75mm thick, while the iPhone 18 Pro Max is expected to reach 8.8mm, a marginal 0.05mm increase that is theoretically small enough for existing cases to accommodate if manufacturing tolerances are generous.
The iPhone 17 Pro dimensions are:
- iPhone 17 Pro: 5.91 inches tall (150mm), 2.83 inches wide (71.9mm), 8.75mm thick
- iPhone 17 Pro Max: 6.43 inches tall (163.4mm), 3.07 inches wide (78mm), 8.75mm thick
The iPhone 18 Pro and iPhone 18 Pro Max will retain the same display sizes as the current generation (6.3-inch and 6.9-inch respectively), and no changes to the overall footprint are expected. The slight thickness increase is likely driven by a larger battery rather than a redesign.
A key factor supporting the OtterBox claim is evidence that Apple may be reusing manufacturing molds from the iPhone 17 Pro for the iPhone 18 Pro line. If Apple reuses the same molds, the dimensions should be compatible, which explains why accessory makers are confident that old cases will fit new phones. Digital Chat Station, a prominent leaker, previously reported that Apple is considering reusing molds for the new generation, a strategy that aligns with the minimal dimensional changes rumored so far.
This approach represents a departure from Apple’s typical annual redesign cycle. Reusing molds suggests Apple is focusing incremental improvements on internals rather than exterior form factor changes.
