How do developers test games across so many devices?
Through a combination of device labs, automation, telemetry and platform certification — and it remains one of the hardest problems in the industry, particularly on mobile where the hardware space is effectively unbounded.
The scale of the problem. Consoles are fixed and testable exhaustively. PCs have an enormous combination space of processors, graphics cards, drivers, operating system versions and peripherals. Mobile is worse, with thousands of device models across widely varying chipsets, screen ratios, memory limits, thermal designs and operating system versions.
How it is actually approached:
Device labs, physical racks of representative hardware — chosen by market share data rather than by trying to cover everything.
Cloud device farms, renting access to hundreds of real devices remotely, which is how most studios achieve breadth.
Tiered support. Defining minimum, recommended and unsupported specifications, and testing thoroughly on representatives of each rather than uniformly.
Automated testing — bots playing through sequences, checking for crashes, memory growth, frame time regressions and visual differences against reference images. Automation catches regressions; it does not catch fun or find novel bugs.
Telemetry from real players, in beta and after launch, reporting crashes with device context — which is how the long tail of device-specific problems is actually found. It is why day-one and early patches exist, and why removing them is impractical.
Platform certification, a mandatory technical check by console holders and storefronts covering suspend and resume behaviour, controller disconnection, storage handling, naming conventions and accessibility requirements. Failing certification delays a release, and the requirements are extensive and strict.
Compatibility layers, where games are tested against translation layers and handheld PC devices, which have become a significant additional target.
What still slips through: rare hardware combinations; specific driver versions, which is why graphics drivers ship game-specific updates; unusual configurations such as ultrawide screens and multiple monitors; and problems only appearing after many hours of play or at scale.
Backwards compatibility adds another dimension, since old games must run on hardware that did not exist when they were made.