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With the release of iOS 26, significant changes have been introduced to system resource scheduling, animation rendering, and background task management—additional transparency layers, complex animations, multiple background services, and enhanced visual effects can lead to app performance fluctuations.

To ensure your iOS app remains smooth, efficient, and provides a good user experience on iOS 26, relying solely on a single tool or simple testing is insufficient. This article shares a practical workflow of "monitoring—analyzing—comparing—optimizing," combining multiple tools.

I. Core Dimensions and Goals of Performance Monitoring

In the iOS 26 environment, we recommend focusing on monitoring the following dimensions to gain a comprehensive understanding of your app's running status:

Frame Rate/Frame Skipping/Rendering Latency: Check if the frame rate is stable during animation transitions, list scrolling, and interface refreshes, and whether there are any noticeable stutters.

CPU/GPU/Main Thread Usage: Identify whether a degraded experience is caused by main thread blocking, high GPU rendering overhead, or intense resource contention.

Resource I/O/Network/File Access Latency: Check whether scrolling or interaction is interrupted by resource loading, file reading/writing, or network requests.

Startup performance and switching response: Have cold start time, foreground/background switching recovery time, and initial rendering latency changed in iOS 26?

Version/Device/System Difference Comparison: Is there performance degradation or differences between iOS 26 and older system versions (such as iOS 25), and between different devices (new/old devices)?

Having clarified these objectives, we move on to the tool combination phase.

II. Multi-Tool Combination:

Role Division and Collaboration Methods To cover the above monitoring dimensions, the following tool combination is recommended, with clear responsibilities defined for each tool:

III. Practical Workflow: How to Systematically Monitor on iOS 26

Step 1: Environment and Baseline Preparation

Select multiple devices (e.g., high-end models, mid-range models, older models), and install iOS 26 and a comparison version (e.g., iOS 25) as baselines on each.

Install the KeyMob performance module and run the same automated script paths (e.g., scrolling lists, page switching, resource loading) on ​​each device.

Simultaneously use Firebase to monitor basic performance metrics to obtain user-level data trends.

Step 2: Real-time Monitoring and Anomaly Tracking

During operation, KeyMob monitors frame rate, number of stutters, and resource loading latency. If the frame rate drops sharply or frame skipping occurs frequently, it automatically tags and records the CPU/GPU/I/O status at that time.

Use Instruments to jump to the corresponding time period on the selected device to view frame rendering time, layer compositing time, main thread blocking, and resource access blocking.

Step 3: Version and Device Comparison Analysis

Summarize the data exported from KeyMob to generate frame rate, latency, and stuttering comparison charts for "iOS 26 vs iOS 25" or "older models vs newer models."

Check the user data in the Firebase dashboard to see if it shows a performance degradation trend on iOS 26.

Analyze whether resource loading structures or animation effects are causing new overhead on iOS 26.

Step 4: Optimization and Regression Verification

Optimize identified bottlenecks (such as high animation layers, synchronous resource loading, file I/O blocking, and network request serialization).

After optimization, repeat the same script path; then use KeyMob + Instruments to compare data changes before and after optimization: frame rate improvement, stuttering reduction, and reduced resource access latency.

Continue to enable KeyMob monitoring in the next version or production environment to observe performance trends on real user terminals.

Optimization Suggestions and Common Pitfall Warnings

Don't just focus on the average frame rate; minimum frame rate, frame skipping count, and response latency better reflect user experience.

Emulators cannot fully represent real devices; real device testing is crucial. In the initial period after the upgrade, iOS 26 devices may undergo index rebuilding and background task batch processing, potentially resulting in higher noise levels in monitoring data.

Older devices are more prone to performance degradation and should be prioritized for coverage.

The overhead of the monitoring tool itself also needs to be controlled to avoid "monitoring causing performance degradation."

Continuous monitoring is more important than a single test. The process should be rerun after each app update/system patch.