TL;DR: Apple's iOS Simulator only offers exact real device models, not arbitrary custom sizes, and that is true for TaloTrace too. Instead, TaloTrace runs your scenarios across several iOS simulator device types in one submission, alongside Android's arbitrary custom geometries, with results grouped for comparison. Alternate device profiles need a paid plan.
Key Takeaways
Apple's constraint, not TaloTrace's: the iOS Simulator only ships exact real-device models. Arbitrary custom screen sizes are not available on iOS, on TaloTrace or anywhere else built on Apple's simulator toolchain.
Android works differently: TaloTrace serves custom Android screen geometries on the fly, without needing a fixed model list.
Matrix, not manual reruns: submit once and TaloTrace runs the same scenarios across several device and OS configurations, with results grouped so you can compare behaviour.
Cloud-hosted, no lab: the iOS Simulator, an Android emulator and a browser are TaloTrace's three execution planes, chosen automatically, with no hardware for you to provision or attach.
Coverage is plan-gated: the free trial runs only the default profile for its platform. Alternate device profiles are unlocked on paid tiers.
Evidence either way: every finding carries a recording, the time window where the defect shows, and a severity rating that can follow your own rubric.
Chasing Screen Coverage Without a Device Lab
Mobile QA and engineering teams hit the same wall the moment they try to reproduce a layout bug reported on an odd iPhone size: the iOS Simulator will not let you dial in that exact resolution. You can pick from Apple's published device models, and nothing else.
On Android, the same job feels different, because emulators accept arbitrary screen geometries. That contrast is where the frustration comes from: it is not that testing custom sizes is impossible everywhere, it is that iOS specifically will not do it.
Why Can't the iOS Simulator Test My Exact Screen Size?
This is an Apple constraint, not a gap in any particular testing tool. The iOS Simulator only ships simulators for defined device models, so there is no way to type in a width and height and get a matching virtual screen the way you can on Android.
TaloTrace's iOS execution plane is the Apple iOS Simulator, with no physical-device support. Each requested device type is served by a simulator of that exact type, and arbitrary custom screen sizes are not offered on iOS. If your reported bug came from a real customer's odd device, the closer option is testing against the nearest available official model rather than an exact match.
How Does TaloTrace Cover the iOS Size Matrix Without Custom Simulators?
Since you cannot dial in one arbitrary iOS size, the practical answer is breadth: run the same scenarios across several iOS simulator device types at once, so you see how the flow behaves on a spread of real screen sizes rather than guessing from one.
TaloTrace's device matrix does this in a single submission. The same scenarios run across several device and OS configurations, and the results are grouped so you can compare behaviour between them. Each device runs on its own lane, and lanes execute independently, so one slow scenario on one simulator does not hold up the others; the matrix submission makes progress across configurations at the same time.
This is plan-gated. The free trial runs the default profile for its platform, and paid tiers unlock alternate device profiles. If broad iOS size coverage is the point of your evaluation, check the pricing page for which tier includes it before you plan a test around it.
What About Android Custom Screen Sizes?
Android is the exception, not the norm. TaloTrace's Android emulator execution plane serves custom screen geometries on the fly, so a matrix run there can include a size you specify directly, alongside standard device profiles.
That difference is Apple's, not TaloTrace's. It shows up because Android emulators are built to accept arbitrary configuration, while Apple's simulator toolchain only ships models it defines. See how TaloTrace tests Android apps for more on that execution plane specifically.
Platform | Custom screen sizes? | How TaloTrace covers it |
|---|---|---|
iOS Simulator | No. Apple ships defined models only | Run several device types in one matrix submission |
Android emulator | Yes. Arbitrary geometries | Request an exact size directly |
What Makes TaloTrace Different on a Matrix Run?
TaloTrace does not navigate by brittle element IDs. It looks at the screen the way a person would, which is the same mechanism that lets it adapt to layout differences generally, including the layout shifts a matrix run surfaces across device sizes.
Findings are also independently reviewed before they reach you. TaloTrace explores your app, records what looks wrong, and then separately verifies each finding, so what lands in your issue view is not the raw, unchecked output of the exploration step. A goal is only marked complete when a machine-checkable predicate proves the outcome, so a scan that cannot prove what it did fails rather than reporting an unverified pass.
What You Get From Every Run?
Each device in a matrix run produces its own findings, and each finding is backed by a screen recording, the time window inside that recording where the defect shows, and TaloTrace's reasoning and step-by-step reproduction.
Severity is rendered as one of five customer-visible levels, Critical through Trivial, shown with its underlying code such as "Critical (P0)". You can supply your own severity-rating guidance and TaloTrace follows it when rating findings, though the five labels themselves stay fixed.
Results start hidden and only become visible once a reviewer approves them, or once a project is explicitly set to auto-approve; low-confidence findings are held separately and always need an explicit per-finding decision. Repeated observations of the same defect collapse into one issue within a run, and a matching candidate in a later run is routed to that existing issue instead of surfacing as new. Findings live in TaloTrace's own issue view and need no external tracker; export to Jira, Linear or GitHub can be turned on per project, and only findings that have passed review can be exported.
What Are the Limits Worth Knowing Before You Start?
You cannot request an arbitrary custom iOS screen size. You choose from the device types TaloTrace's iOS Simulator plane serves; there is no free-text width and height input for iOS the way there is for Android.
No platform offers physical-device execution. Browser, Android emulator and iOS Simulator are all cloud-hosted and virtual, which is what removes the device lab, but it also means you are always testing against a simulator or emulator rather than physical hardware.
The device matrix itself is not on every plan. The free trial runs the default profile for its platform, and alternate device profiles unlock on paid tiers, so confirm your tier covers the spread you need before building a test plan around it.
How to Get TaloTrace?
Most tiers are published and buyable directly; see the pricing page for current tiers and what each includes. Enterprise terms are handled separately, by custom arrangement.
If you want to see the device matrix and iOS coverage in action against your own app, TaloTrace's beta is open now. Apply for early access.
Frequently Asked Questions
Can I test an arbitrary custom iOS screen size with TaloTrace?
No. The iOS Simulator only ships models for defined Apple device types, and TaloTrace's iOS execution plane follows that constraint. You can run several exact device types in one matrix submission instead of one custom size.
Does TaloTrace support custom Android screen sizes?
Yes. TaloTrace's Android emulator execution plane serves custom screen geometries on the fly, so you can request a specific size alongside standard device profiles.
Is the device matrix available on every plan?
No. The free trial runs the default profile for its platform, and alternate device profiles are unlocked on paid tiers. Check the pricing page for which tier fits your coverage needs.
Does TaloTrace test on physical iOS devices?
No. TaloTrace's iOS execution plane is the Apple iOS Simulator, and physical devices are not offered on any platform.
How many device configurations can I run in one submission?
You can run several device and OS configurations in a single submission, with results grouped so you can compare behaviour. Each device runs on its own lane, and lanes progress independently.
What do I get back from a matrix run?
Each configuration produces its own findings, each backed by a recording, the time window where the defect shows, and severity ratings that can follow your own review guidance.
