- Device farms flake because they reuse state.
- Device farms prioritize utilization over stability, so devices get reused without full resets and leftover app/system data leaks into tests—making end-to-end automation unpredictable and hard to trust.
- Reliable mobile automation starts with a clean state every run.
- QA Wolf’s mobile QA automation cold-boots each test with a clean state and deep system control. For end-to-end automation, isolation isn’t a nice-to-have, it’s the baseline for consistent results.
- Android testing at scale requires isolated emulators, not shared hardware.
- ‍QA Wolf uses custom-built Android emulators with nested virtualization so each run is fully isolated—no shared hardware, no cross-test contamination—while still matching real-world CPU, memory, and sensor behavior at massive scale.
- Real iOS behavior requires real devices.
- ‍QA Wolf tests on physical iPhones with OS-level control, enabling reliable automation of push notifications, system prompts, and permission dialogs that simulators and device farms often fail to handle.‍
- End-to-end mobile testing should reflect real cross-device user journeys.
- ‍QA Wolf supports full cross-platform flows across Android, iOS, and desktop—so a single automated test can start on one device, move through email or system handoffs, and finish on another, just like real users do.
QA Wolf provides automated mobile testing for Android and iOS with zero flakes, full parallelism, and complete system control—without the limitations of traditional device farms. Teams can use the QA Wolf platform directly or rely on us to build, run, and maintain end-to-end mobile tests, all on infrastructure we own and control.
Why mobile app testing automation fails with traditional device farms
Most teams know their mobile E2E test coverage isn't where it needs to be. It's a structural problem.
Building the right system requires access to the right environments: real devices, emulators, or simulators, depending on the application. Teams have two options: they can build and maintain an in-house lab or they can rent time on a third-party device farm.
In-house labs offer complete control, custom configurations, consistent environments, and deep debugging access. But they're expensive to build and time-consuming to maintain. Supporting multiple devices and OS versions adds constant overhead, and keeping everything stable requires dedicated resources. In-house labs are out of reach for most teams.
Most teams opt for the alternative: device farms.
The problem: Device farms prioritize utilization over stability
Anyone who has worked with device farms knows they are slow, expensive, and annoying. A typical test run might queue for several minutes, flake halfway through, and return logs buried inside a 20-minute video with no indexing.
The reason they behave this way isn't bad design—it's intentional. These platforms are designed to maximize device utilization, rather than optimize test feedback. That model works fine for manual testing, but it is not suited to the demands of automation.
Device farms provide hardware, but not control. To make mobile test automation work at scale, teams need cold boots, state resets, OS-level hooks, and support for flows like push notifications or Apple ID login. Most of that is off-limits using device farms, because enabling it would slow down reuse, and reuse drives the device farm business model.
To support manual and exploratory testing, device farms prioritize real-time access over test isolation. That means devices are reused as quickly as possible, often without full resets between sessions.
For CI and dev teams, they offer just enough access to run basic functional checks, but not the low-level control needed to automate complex workflows. And to keep costs down across all use cases, they throttle resources and limit visibility into system behavior.
All of that is fine—if you're running one-off tests by hand or automating a login screen validation after a commit. But for E2E automation at scale, it falls apart.
The result: Test instability and unpredictable failures
When teams attempt to use modern device farms for test automation, they inevitably encounter test instability.
When devices get reused between tests, leftover data and timing delays can cause complex flows to fail in unpredictable ways. Failures become harder to reproduce. The test suite becomes harder to trust.
That's because device farms aren't built for automation stability—they're built to keep devices in constant use. Without full resets between runs, leftover app data and system state leak into tests, causing flakiness and inconsistent results.
How QA Wolf solves mobile testing automation challenges
QA Wolf's business is different. We don't rent devices—we deliver working tests.
That means clean state, deep system control, instant parallelism, and zero flakes. Those things sound nice for any kind of testing, but for end-to-end automation, they're non-negotiable.
Manual testers can recover from a flaky state or poke around a device to troubleshoot. Automated tests can't. If the state isn't clean, if the system isn't predictable, if results aren't consistent, the suite breaks. Fast.
Device farms can't support that level of stability or control without blowing up their economics. So instead of forcing general-purpose infrastructure to work for automation, we built our own, explicitly designed to deliver reliable mobile test execution at scale.
Delivering fast, accurate, and comprehensive test coverage for mobile automation requires infrastructure built for that purpose. Device farms generate revenue when the devices are in use and are designed to offer customers the most ways to use them. That means devices are shared, environments are recycled, and system-level access is limited—all of which work against the stability of automation.
We built something else. Our system is purpose-built for high-throughput, reliable, end-to-end test execution. It provides cold boots, clean state, full parallelism, and deep system control—because those aren't nice-to-haves in automation, they're the baseline for trustworthy results.
And because coverage isn't just a tooling problem, we also build, maintain, and update every test to reflect how your app actually works.
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QA Wolf’s mobile testing capabilities
Here's what our system does:
Runs full end-to-end flows across platforms
We're the only solution that lets you test real user journeys across Android, iOS, and desktop. Start a test case on one device and finish it on another—no problem.
Executes in full parallel without bottlenecks
Running mobile tests in parallel is tricky. Most clouds don't fully isolate state between tests, leading to flakiness and unpredictable failures.
We run each test in a clean environment on a real device or an emulator, allowing you to scale to thousands in parallel without delays or conflicts.
Provisions stable, flake-resistant environments for every test run with no lag
We run tests in controlled environments with consistent resources. That means fewer flaky results and no surprises from unstable shared device farms.
Devices stay warmed and ready, so tests launch instantly with no boot or queue delay.
Increases visibility and eases debugging
When a test fails, testers get detailed info right away. They can dig into failures without rerunning entire test suites or waiting around for devices. We also support line-by-line execution to expedite debugging.
Delivers fast, reliable feedback loops on real system behavior
Thanks to parallel execution, stable environments, and efficient debugging, your team receives quick feedback, even for complex applications across multiple devices and OS versions.
How to test Android appsÂ
QA Wolf tests Android apps using custom-built emulators with nested virtualization, designed from day one for speed, scale, and stability. Unlike platforms that rely on physical devices (which don’t scale) or stock emulators (which fall apart under load), our Android cloud provides complete isolation and instant scalability, fully integrated with our E2E testing infrastructure to run high-volume tests reliably.Â
Isolate every test with nested virtualization
Each emulator runs in total isolation using nested virtualization: no shared hardware, no queues, no cross-test contamination.
Tune emulators for real-world accuracy
Every emulator is optimized to replicate real-world CPU, memory, and sensor conditions, ensuring consistent test behavior and making bugs easier to track down.
Scale test capacity instantly on demand
We can spin up thousands of emulators instantly. Our system grows with your test suite, without waiting for hardware or hitting quota ceilings.
Cover real behavior without physical devices
Our Android emulators are optimized for automation and support nearly all functional test cases, including navigation, network conditions, system prompts, and backgrounding.
That reduces the need for physical devices, speeds up test runs, and still gives you reliable, production-relevant results.
How to test iOS appsÂ
Simulators don’t cut it for real iOS testing. They can’t replicate hardware behavior or support critical flows like push notifications, system prompts, background tasks, or cross-app interactions. That’s why QA Wolf runs tests exclusively on real, physical iPhones that we own and control, providing full system-level access and accurate, production-grade results.
Test real behavior on real devices
Our tests replicate actual user behavior on real hardware. That means reliable coverage for gesture-based navigation, system dialogs, deep links, and device-specific behaviors that simulators can't reproduce.
Access system-level conditions with full control
Because we manage the devices directly, we can test under real-world conditions: low battery, backgrounding, location changes, throttled network, and more. No simulator hacks. No provider limits.
Execute reliably with a custom WebDriver runtime
We use a proprietary agent to run and debug tests line by line, with complete visibility into execution.
That reduces flakiness, shortens feedback loops, and speeds up root cause analysis. It also means we can cover more use cases than any other service out there.
Control the OS with re-signed iOS builds
We re-sign iOS app builds with custom entitlements, giving us control over permissions, push notification handling, and inter-app communication. That enables reliable automation of flows that break on most device clouds, including onboarding, install-time dialogs, and OS-triggered permission prompts.
Device farms vs. QA Wolf: What's the difference?
Cover what others can’t. Maintain less. Ship with confidence.
QA Wolf delivers the kind of test coverage most teams think is out of reach because we built our system to handle it.
We support real-world user flows, including Apple ID logins, push notifications, cross-device handoffs, camera and sensor usage, and background tasks. These are the flows that matter most—and they're precisely what gets skipped when the test environment isn't up to the job.
Because we built for automation from the ground up, tests run in stable, repeatable environments, and failures are easy to diagnose and resolve. Maintenance is minimal. Parallel execution removes bottlenecks. Your team gets fast feedback without burning time on upkeep.
And we do the work. We don't just provide infrastructure—we write, run, and maintain your tests for you. That's how we deliver more coverage, with less maintenance, and show value faster.
Device farms weren't built for this. We were.
How do you test mobile apps on real devices without flaky end-to-end tests?
Use isolated, clean-state environments for every run. QA Wolf eliminates flakiness by starting each test from a cold boot with a full state reset, so no leftover data or OS state leaks between sessions. On Android, tests run in custom emulators with nested virtualization for total isolation; on iOS, tests run on real physical iPhones that QA Wolf owns and controls to enforce consistent device state and system-level reliability.
What's the best way to test iOS apps for push notifications and system permission prompts?
Test on real iPhones with OS-level control, not simulators. QA Wolf runs iOS automation on physical devices and re-signs iOS builds with custom entitlements so tests can reliably handle push notifications, install-time dialogs, and OS-triggered permission prompts. A proprietary WebDriver runtime also supports line-by-line execution, making these hard-to-automate interactions easier to debug and reproduce.
How can you test Android apps at scale without maintaining a physical device lab?
Use emulators designed for high-throughput E2E automation with strong isolation. QA Wolf uses custom-built Android emulators with nested virtualization so each test runs in a separate, clean environment (no shared hardware, no cross-test contamination). This enables instant scaling to thousands of parallel runs while still covering real-world behaviors like navigation, system prompts, backgrounding, and varied network conditions.
Can one automated test cover a full user journey across Android, iOS, and desktop?
Yes—if your test platform supports cross-device and cross-platform execution. QA Wolf can run a single end-to-end test that starts on one device and finishes on another (including desktop), which is useful for real user journeys like starting checkout on an Android phone, receiving a confirmation email, and completing the purchase on desktop in the same automated flow.
What do QA automation services for mobile app testing include besides test execution?
Full-service QA automation should cover test creation and ongoing upkeep, not just infrastructure. QA Wolf builds, runs, maintains, and updates your mobile end-to-end tests so coverage stays aligned with how the app actually works as it changes. It also provides faster debugging via detailed failure info and line-by-line execution, reducing the time spent triaging flaky or hard-to-reproduce failures.