功能和 API

Android 16 面向开发者引入了一些出色的新功能和 API。以下各部分总结了这些功能，可帮助您开始使用相关 API。

如需查看新增、修改和移除的 API 的详细列表，请参阅 API 差异报告。如需详细了解新的 API，请访问 Android API 参考文档，新 API 会突出显示以方便查看。

您还应查看平台变更可能会在哪些方面影响您的应用。如需了解详情，请参阅以下页面：

核心功能

Android 包含一些新的 API，可扩展 Android 系统的核心功能。

2025 年发布了两个 Android API

  • 此预览版适用于 Android 的下一个主要版本，计划于 2025 年第 2 季度发布。此版本与我们过去的所有 API 版本类似，我们可以进行计划性的行为更改，这些更改通常与 targetSdkVersion 相关联。
  • 我们计划提前一个季度（2021 年第 2 季度，而非之前的第 3 季度）发布主要版本，以便更好地与整个生态系统中的设备发布时间表保持一致，让更多设备能够更早地搭载 Android 主要版本。由于主要版本将于第 2 季度发布，因此您需要比往年提前几个月进行年度兼容性测试，以确保您的应用已做好准备。
  • 我们计划在 2025 年第 4 季度再发布一次，届时还将推出新的开发者 API。2025 年只有第二季度的主要版本包含可能影响应用的计划行为变更。

除了新的开发者 API 之外，第 4 季度次要版本还将包含功能更新、优化和 bug 修复；其中不会包含任何会影响应用的行为变更。

2025 年 Android 版本的时间轴视图，请注意，25Q2 版本是一个主要版本，25Q4 版本是一个次要版本。

我们将继续每季度发布 Android 版本。在 API 版本之间，第 1 季度和第 3 季度的更新将提供增量更新，以帮助确保持续提供高质量的服务。我们正积极与设备合作伙伴合作，将 Q2 版本推广到尽可能多的设备。

在主要版本和次要版本中使用新 API

目前，使用 SDK_INT 常量与 VERSION_CODES 结合使用，即可通过检查 API 级别来保护代码块。我们将继续支持主要 Android 版本。

if (SDK_INT >= VERSION_CODES.BAKLAVA) {
  // Use APIs introduced in Android 16
}

新的 SDK_INT_FULL 常量可用于针对主要版本和次要版本进行 API 检查，并使用新的 VERSION_CODES_FULL 枚举。

if (SDK_INT_FULL >= VERSION_CODES_FULL.[MAJOR or MINOR RELEASE]) {
  // Use APIs introduced in a major or minor release
}

您还可以使用 Build.getMinorSdkVersion() 方法仅获取 SDK 次要版本。

val minorSdkVersion = Build.getMinorSdkVersion(VERSION_CODES_FULL.BAKLAVA)

这些 API 尚未最终确定，可能会发生变化，因此如果您有任何疑虑，请向我们发送反馈。

用户体验和系统界面

Android 16 为应用开发者和用户提供了更多控制权和灵活性，以便他们根据自己的需求配置设备。

以进度为中心的通知

Android 16 introduces progress-centric notifications to help users seamlessly track user-initiated, start-to-end journeys.

Notification.ProgressStyle is a new notification style that lets you create progress-centric notifications. Key use cases include rideshare, delivery, and navigation. Within the Notification.ProgressStyle class, you can denote states and milestones in a user journey using points and segments.

如需了解详情，请参阅以进度为中心的通知文档页面。

A progress-centric notification displayed on the lockscreen.
A progress-centric notification displayed in the notification shade.

预测性返回更新

Android 16 adds new APIs to help you enable predictive back system animations in gesture navigation such as the back-to-home animation. Registering the onBackInvokedCallback with the new PRIORITY_SYSTEM_NAVIGATION_OBSERVER allows your app to receive the regular onBackInvoked call whenever the system handles a back navigation without impacting the normal back navigation flow.

Android 16 additionally adds the finishAndRemoveTaskCallback() and moveTaskToBackCallback. By registering these callbacks with the OnBackInvokedDispatcher, the system can trigger specific behaviors and play corresponding ahead-of-time animations when the back gesture is invoked.

更丰富的触感反馈

Android has exposed control over the haptic actuator ever since its inception.

Android 11 added support for more complex haptic effects that more advanced actuators could support through VibrationEffect.Compositions of device-defined semantic primitives.

Android 16 adds haptic APIs that let apps define the amplitude and frequency curves of a haptic effect while abstracting away differences between device capabilities.

开发者工作效率和工具

虽然我们的大部分工作都是围绕 Android Studio、Jetpack Compose 和 Android Jetpack 库等工具来提高您的工作效率，但我们始终在寻找平台中的方法来帮助您实现自己的愿景。

动态壁纸的内容处理

In Android 16, the live wallpaper framework is gaining a new content API to address the challenges of dynamic, user-driven wallpapers. Currently, live wallpapers incorporating user-provided content require complex, service-specific implementations. Android 16 introduces WallpaperDescription and WallpaperInstance. WallpaperDescription lets you identify distinct instances of a live wallpaper from the same service. For example, a wallpaper that has instances on both the home screen and on the lock screen may have unique content in both places. The wallpaper picker and WallpaperManager use this metadata to better present wallpapers to users, streamlining the process for you to create diverse and personalized live wallpaper experiences.

性能和电池

Android 16 引入了可帮助您收集应用相关数据分析的 API。

系统触发的性能分析

ProfilingManager was added in Android 15, giving apps the ability to request profiling data collection using Perfetto on public devices in the field. However, since this profiling must be started from the app, critical flows such as startups or ANRs would be difficult or impossible for apps to capture.

To help with this, Android 16 introduces system-triggered profiling to ProfilingManager. Apps can register interest in receiving traces for certain triggers such as cold start reportFullyDrawn or ANRs, and then the system starts and stops a trace on the app's behalf. After the trace completes, the results are delivered to the app's data directory.

ApplicationStartInfo 中的启动组件

ApplicationStartInfo was added in Android 15, allowing an app to see reasons for process start, start type, start times, throttling, and other useful diagnostic data. Android 16 adds getStartComponent() to distinguish what component type triggered the start, which can be helpful for optimizing the startup flow of your app.

更好地进行作业内省

JobScheduler#getPendingJobReason() API 会返回作业可能处于待处理状态的原因。不过，作业处于待处理状态的原因可能有多种。

在 Android 16 中，我们引入了一个新 API JobScheduler#getPendingJobReasons(int jobId)，该 API 会返回作业处于待处理状态的多种原因，包括开发者设置的显式约束条件和系统设置的隐式约束条件。

我们还引入了 JobScheduler#getPendingJobReasonsHistory(int jobId)，用于返回最新约束条件更改的列表。

我们建议您使用该 API 来调试作业可能无法执行的原因，尤其是在您发现某些任务的成功率降低或某些作业完成延迟存在 bug 时。例如，未能在后台更新微件，或在应用启动之前未能调用预加载作业。

这还有助于您更好地了解某些作业是否因系统定义的约束条件而无法完成，而不是因明确设置的约束条件而无法完成。

自动调节刷新率

Adaptive refresh rate (ARR), introduced in Android 15, enables the display refresh rate on supported hardware to adapt to the content frame rate using discrete VSync steps. This reduces power consumption while eliminating the need for potentially jank-inducing mode-switching.

Android 16 introduces hasArrSupport() and getSuggestedFrameRate(int) while restoring getSupportedRefreshRates() to make it easier for your apps to take advantage of ARR. RecyclerView 1.4 internally supports ARR when it is settling from a fling or smooth scroll, and we're continuing our work to add ARR support into more Jetpack libraries. This frame rate article covers many of the APIs you can use to set the frame rate so that your app can directly use ARR.

ADPF 中的裕度 API

SystemHealthManager 引入了 getCpuHeadroom 和 getGpuHeadroom API，旨在为游戏和资源密集型应用提供可用 CPU 和 GPU 资源的估算值。通过这些方法，您可以评估应用或游戏如何以最佳方式改善系统运行状况，尤其是在与用于检测热节流的其他 Android 动态性能框架 (ADPF) API 搭配使用时。

在受支持的设备上使用 CpuHeadroomParams 和 GpuHeadroomParams，您可以自定义用于计算余量的时间范围，并在平均资源可用性或最低资源可用性之间进行选择。这有助于您相应地减少 CPU 或 GPU 资源用量，从而提升用户体验并延长电池续航时间。

无障碍

Android 16 新增了无障碍功能 API 和功能，可帮助您让所有用户都能使用您的应用。

改进了无障碍功能 API

Android 16 adds additional APIs to enhance UI semantics that help improve consistency for users that rely on accessibility services, such as TalkBack.

Outline text for maximum text contrast

Users with low vision often have reduced contrast sensitivity, making it challenging to distinguish objects from their backgrounds. To help these users, Android 16 introduces outline text, replacing high contrast text, which draws a larger contrasting area around text to greatly improve legibility.

Android 16 contains new AccessibilityManager APIs to let your apps check or register a listener to see if this mode is enabled. This is primarily for UI Toolkits like Compose to offer a similar visual experience. If you maintain a UI Toolkit library or your app performs custom text rendering that bypasses the android.text.Layout class then you can use this to know when outline text is enabled.

Text with enhanced contrast before and after Android 16's new outline text accessibility feature

Duration added to TtsSpan

Android 16 extends TtsSpan with a TYPE_DURATION, consisting of ARG_HOURS, ARG_MINUTES, and ARG_SECONDS. This lets you directly annotate time duration, ensuring accurate and consistent text-to-speech output with services like TalkBack.

Support elements with multiple labels

Android currently allows UI elements to derive their accessibility label from another, and now offers the ability for multiple labels to be associated, a common scenario in web content. By introducing a list-based API within AccessibilityNodeInfo, Android can directly support these multi-label relationships. As part of this change, we've deprecated AccessibilityNodeInfo#setLabeledBy and #getLabeledBy in favor of #addLabeledBy, #removeLabeledBy, and #getLabeledByList.

Improved support for expandable elements

Android 16 adds accessibility APIs that allow you to convey the expanded or collapsed state of interactive elements, such as menus and expandable lists. By setting the expanded state using setExpandedState and dispatching TYPE_WINDOW_CONTENT_CHANGED AccessibilityEvents with a CONTENT_CHANGE_TYPE_EXPANDED content change type, you can ensure that screen readers like TalkBack announce state changes, providing a more intuitive and inclusive user experience.

Indeterminate ProgressBars

Android 16 adds RANGE_TYPE_INDETERMINATE, giving a way for you to expose RangeInfo for both determinate and indeterminate ProgressBar widgets, allowing services like TalkBack to more consistently provide feedback for progress indicators.

Tri-state CheckBox

The new AccessibilityNodeInfo getChecked and setChecked(int) methods in Android 16 now support a "partially checked" state in addition to "checked" and "unchecked." This replaces the deprecated boolean isChecked and setChecked(boolean).

Supplemental descriptions

When an accessibility service describes a ViewGroup, it combines content labels from its child views. If you provide a contentDescription for the ViewGroup, accessibility services assume you are also overriding the description of non-focusable child views. This can be problematic if you want to label things like a drop-down (for example, "Font Family") while preserving the current selection for accessibility (for example, "Roboto"). Android 16 adds setSupplementalDescription so you can provide text that provides information about a ViewGroup without overriding information from its children.

Required form fields

Android 16 adds setFieldRequired to AccessibilityNodeInfo so apps can tell an accessibility service that input to a form field is required. This is an important scenario for users filling out many types of forms, even things as simple as a required terms and conditions checkbox, helping users to consistently identify and quickly navigate between required fields.

将手机作为 LEA 助听器的语音通话麦克风输入源

Android 16 新增了一项功能，让 LE Audio 助听器用户能够在助听器的内置麦克风和手机上的麦克风之间切换，以进行语音通话。在嘈杂的环境或助听器麦克风可能无法正常工作的其他情况下，这会很有帮助。

LEA 助听器的环境音量控制

Android 16 adds the capability for users of LE Audio hearing aids to adjust the volume of ambient sound that is picked up by the hearing aid's microphones. This can be helpful in situations where background noise is too loud or too quiet.

相机

Android 16 增强了对专业相机用户的支持，允许进行混合自动曝光以及精确的色温和色调调整。新的夜间模式指示器可帮助应用了解何时切换到夜间模式相机会议以及何时从夜间模式相机会议切换回来。新的 Intent 操作可让您更轻松地拍摄动态照片，并且我们还在不断改进 UltraHDR 图片，支持 HEIC 编码和 ISO 21496-1 草稿标准中的新参数。

混合自动曝光

Android 16 adds new hybrid auto-exposure modes to Camera2, allowing you to manually control specific aspects of exposure while letting the auto-exposure (AE) algorithm handle the rest. You can control ISO + AE, and exposure time + AE, providing greater flexibility compared to the current approach where you either have full manual control or rely entirely on auto-exposure.

fun setISOPriority() {
    // ... (Your existing code before the snippet) ...

    val availablePriorityModes = mStaticInfo.characteristics.get(
        CameraCharacteristics.CONTROL_AE_AVAILABLE_PRIORITY_MODES
    )

    // ... (Your existing code between the snippets) ...

    // Turn on AE mode to set priority mode
    reqBuilder.set(
        CaptureRequest.CONTROL_AE_MODE,
        CameraMetadata.CONTROL_AE_MODE_ON
    )
    reqBuilder.set(
        CaptureRequest.CONTROL_AE_PRIORITY_MODE,
        CameraMetadata.CONTROL_AE_PRIORITY_MODE_SENSOR_SENSITIVITY_PRIORITY
    )
    reqBuilder.set(
        CaptureRequest.SENSOR_SENSITIVITY,
        TEST_SENSITIVITY_VALUE
    )
    val request: CaptureRequest = reqBuilder.build()

    // ... (Your existing code after the snippet) ...
}

精确的色温和色调调整

Android 16 增加了对相机的精细色温和色调调整的支持，以更好地支持专业视频录制应用。在较低版本的 Android 中，您可以通过 CONTROL_AWB_MODE 控制白平衡设置，其中包含仅限于预设列表的选项，例如白炽灯、多云和黄昏。COLOR_CORRECTION_MODE_CCT 可让您使用 COLOR_CORRECTION_COLOR_TEMPERATURE 和 COLOR_CORRECTION_COLOR_TINT 根据相关色温精确调整白平衡。

fun setCCT() {
    // ... (Your existing code before this point) ...

    val colorTemperatureRange: Range<Int> =
        mStaticInfo.characteristics[CameraCharacteristics.COLOR_CORRECTION_COLOR_TEMPERATURE_RANGE]

    // Set to manual mode to enable CCT mode
    reqBuilder[CaptureRequest.CONTROL_AWB_MODE] = CameraMetadata.CONTROL_AWB_MODE_OFF
    reqBuilder[CaptureRequest.COLOR_CORRECTION_MODE] = CameraMetadata.COLOR_CORRECTION_MODE_CCT
    reqBuilder[CaptureRequest.COLOR_CORRECTION_COLOR_TEMPERATURE] = 5000
    reqBuilder[CaptureRequest.COLOR_CORRECTION_COLOR_TINT] = 30

    val request: CaptureRequest = reqBuilder.build()

    // ... (Your existing code after this point) ...
}

以下示例展示了应用不同色温和色调调整后的照片效果：

未应用色温或色调调整的原始图片。
将色温调整为 3000 的图片。
将色温调整为 7000 的图片。


将色调级别降低 50 的图片。
色调级别提高了 50 的图片。

相机夜间模式场景检测

To help your app know when to switch to and from a night mode camera session, Android 16 adds EXTENSION_NIGHT_MODE_INDICATOR. If supported, it's available in the CaptureResult within Camera2.

This is the API we briefly mentioned as coming soon in the How Instagram enabled users to take stunning low light photos blog post. That post is a practical guide on how to implement night mode together with a case study that links higher-quality in-app night mode photos with an increase in the number of photos shared from the in-app camera.

动态照片拍摄 intent 操作

Android 16 adds standard Intent actions — ACTION_MOTION_PHOTO_CAPTURE, and ACTION_MOTION_PHOTO_CAPTURE_SECURE — which request that the camera application capture a motion photo and return it.

You must either pass an extra EXTRA_OUTPUT to control where the image will be written, or a Uri through Intent.setClipData(ClipData). If you don't set a ClipData, it will be copied there for you when calling Context.startActivity(Intent).

An example of a motion photo, showing the still image followed by the motion playback.

UltraHDR 图片增强功能

标准动态范围 (SDR) 与高动态范围 (HDR) 图片质量对比示意图。

Android 16 继续致力于通过 UltraHDR 图片提供出色的图片质量。它添加了对 HEIC 文件格式的 UltraHDR 图片的支持。这些图片将获得 ImageFormat 类型 HEIC_ULTRAHDR，并包含类似于现有 UltraHDR JPEG 格式的嵌入式增益图。我们还在努力为 UltraHDR 添加 AVIF 支持，敬请期待。

此外，Android 16 在 UltraHDR 中实现了 ISO 21496-1 草稿标准中的其他参数，包括能够获取和设置应应用增益图算法的色彩空间，以及支持使用 SDR 增益图的 HDR 编码基础图片。

图形

Android 16 包含最新的图形改进，例如使用 AGSL 实现自定义图形效果。

使用 AGSL 实现自定义图形效果

Android 16 adds RuntimeColorFilter and RuntimeXfermode, allowing you to author complex effects like Threshold, Sepia, and Hue Saturation and apply them to draw calls. Since Android 13, you've been able to use AGSL to create custom RuntimeShaders that extend Shader. The new API mirrors this, adding an AGSL-powered RuntimeColorFilter that extends ColorFilter, and a Xfermode effect that lets you implement AGSL-based custom compositing and blending between source and destination pixels.

private val thresholdEffectString = """
    uniform half threshold;

    half4 main(half4 c) {
        half luminosity = dot(c.rgb, half3(0.2126, 0.7152, 0.0722));
        half bw = step(threshold, luminosity);
        return bw.xxx1 * c.a;
    }"""

fun setCustomColorFilter(paint: Paint) {
   val filter = RuntimeColorFilter(thresholdEffectString)
   filter.setFloatUniform(0.5);
   paint.colorFilter = filter
}

连接

Android 16 更新了平台，让您的应用能够使用通信和无线技术方面的最新进展。

测距（安全性增强）

Android 16 在搭载 Wi-Fi 6 的 802.11az 的受支持设备上为 Wi-Fi 位置信息添加了对强大的安全功能的支持，让应用能够将该协议的更高精确性、更高可伸缩性和动态调度与安全增强功能（包括基于 AES-256 的加密和防范中间人攻击）相结合。这样，在近距离使用情形（例如解锁笔记本电脑或车门）时，便可更安全地使用该功能。802.11az 与 Wi-Fi 6 标准集成，可利用其基础架构和功能实现更广泛的采用和更轻松的部署。

通用测距 API

Android 16 包含新的 RangingManager，它提供了在受支持的硬件上确定本地设备与远程设备之间的距离和角度的方法。RangingManager 支持使用各种测距技术，例如 BLE 信道声音探测、基于 BLE RSSI 的测距、超宽带和 Wi-Fi 往返时间。

配套设备管理器设备存在情况

In Android 16, new APIs are being introduced for binding your companion app service. Service will be bound when BLE is in range and Bluetooth is connected and service will be unbound when BLE is out of range or Bluetooth is disconnected. App will receives a new 'onDevicePresenceEvent()' callback based on various of DevicePresenceEvent. More details can be found in 'startObservingDevicePresence(ObservingDevicePresenceRequest)'.

媒体

Android 16 包含各种可提升媒体体验的功能。

改进了照片选择器

照片选择器为用户提供了一种安全的内置授权方式，让用户可以向应用授予对本地存储空间和云端存储空间中所选图片和视频的访问权限，而不是对整个媒体库的访问权限。通过 Google 系统更新和 Google Play 服务组合使用模块化系统组件，该工具向后支持到 Android 4.4（API 级别 19）。只需几行代码即可与相关的 Android Jetpack 库集成。

Android 16 对照片选择器进行了以下改进：

  • 嵌入式照片选择器：新 API，可让应用将照片选择器嵌入其视图层次结构中。这样，它就感觉像是应用中更为集成的一部分，同时仍可利用进程隔离功能，让用户能够选择媒体，而无需应用拥有过于宽泛的权限。为了最大限度地提高跨平台版本的兼容性并简化集成，如果您想集成嵌入式照片选择器，则需要使用即将推出的 Android Jetpack 库。
  • 照片选择器中的云搜索：新的 API 可让 Android 照片选择器从云端媒体提供商中进行搜索。照片选择器中的搜索功能即将推出。

高级专业视频

Android 16 引入了对高级专业视频 (APV) 编解码器的支持，该编解码器专为专业级高品质视频录制和后期制作而设计。

APV 编解码器标准具有以下特点：

  • 感知上无损的视频画质（接近原始视频画质）
  • 复杂度低且吞吐量高的仅帧内编码（无像素域预测），以更好地支持编辑工作流
  • 支持高比特率范围（最高几十 Gbps），适用于 2K、4K 和 8K 分辨率内容，由轻量级熵编码方案实现
  • 帧平铺，用于沉浸式内容和启用并行编码和解码
  • 支持各种色度采样格式和位深
  • 支持多次解码和重新编码，且不会严重降低视觉质量
  • 支持多视图视频和辅助视频，例如深度、Alpha 和预览
  • 支持 HDR10/10+ 和用户定义的元数据

OpenAPV 项目提供了 APV 的参考实现。Android 16 将实现对 APV 422-10 配置文件的支持，该配置文件提供 YUV 422 色彩采样以及 10 位编码，并且目标比特率最高可达 2 Gbps。

隐私权

Android 16 包含多种有助于应用开发者保护用户隐私的功能。

健康数据共享更新

Health Connect adds ACTIVITY_INTENSITY, a data type defined according to World Health Organization guidelines around moderate and vigorous activity. Each record requires the start time, the end time, and whether the activity intensity is moderate or vigorous.

Health Connect also contains updated APIs supporting medical records. This allows apps to read and write medical records in FHIR format with explicit user consent.

Privacy Sandbox on Android

Android 16 incorporates the latest version of the Privacy Sandbox on Android, part of our ongoing work to develop technologies where users know their privacy is protected. Our website has more about the Privacy Sandbox on Android developer beta program to help you get started. Check out the SDK Runtime which allows SDKs to run in a dedicated runtime environment separate from the app they are serving, providing stronger safeguards around user data collection and sharing.

安全

Android 16 包含有助于增强应用安全性和保护应用数据的功能。

密钥共享 API

Android 16 添加了一些 API，这些 API 支持与其他应用共享对 Android Keystore 密钥的访问权限。新的 KeyStoreManager 类支持按应用 uid 授予和撤消对密钥的访问权限，并包含一个供应用访问共享密钥的 API。

设备规格

Android 16 为您的应用提供支持，让您充分利用 Android 的设备类型。

电视的标准化画质和音质框架

The new MediaQuality package in Android 16 exposes a set of standardized APIs for access to audio and picture profiles and hardware-related settings. This allows streaming apps to query profiles and apply them to media dynamically:

  • Movies mastered with a wider dynamic range require greater color accuracy to see subtle details in shadows and adjust to ambient light, so a profile that prefers color accuracy over brightness may be appropriate.
  • Live sporting events are often mastered with a narrow dynamic range, but are often watched in daylight, so a profile that preferences brightness over color accuracy can give better results.
  • Fully interactive content wants minimal processing to reduce latency, and wants higher frame rates, which is why many TV's ship with a game profile.

The API allows apps to switch between profiles and users to enjoy tuning supported TVs to best suit their content.

国际化

Android 16 新增了多项功能，可在设备以不同语言运行时提升用户体验。

竖排文字

Android 16 添加了对垂直渲染和测量文本的低级支持，以便为库开发者提供基本的垂直书写支持。这对于日语等通常使用竖向书写系统的语言特别有用。Paint 类中添加了一个新标志 VERTICAL_TEXT_FLAG。使用 Paint.setFlags 设置此标志后，Paint 的文本测量 API 将报告垂直进度，而不是水平进度，并且 Canvas 将垂直绘制文本。

val text = "「春は、曙。」"
Box(
    Modifier.padding(innerPadding).background(Color.White).fillMaxSize().drawWithContent {
        drawIntoCanvas { canvas ->
            val paint = Paint().apply { textSize = 64.sp.toPx() }
            // Draw text vertically
            paint.flags = paint.flags or VERTICAL_TEXT_FLAG
            val height = paint.measureText(text)
            canvas.nativeCanvas.drawText(
                text,
                0,
                text.length,
                size.width / 2,
                (size.height - height) / 2,
                paint
            )
        }
    }
) {}

自定义度量衡制

Users can now customize their measurement system in regional preferences within Settings. The user preference is included as part of the locale code, so you can register a BroadcastReceiver on ACTION_LOCALE_CHANGED to handle locale configuration changes when regional preferences change.

Using formatters can help match the local experience. For example, "0.5 in" in English (United States), is "12,7 mm" for a user who has set their phone to English (Denmark) or who uses their phone in English (United States) with the metric system as the measurement system preference.

To find these settings, open the Settings app and navigate to System > Languages & region.