---
title: Session Replay iOS Middleware
description: 
product: session-replay
lang: en
last_updated: 2025-03-18
token_estimate: 4561
---
# Session Replay iOS Middleware

> For AI agents: a documentation index is available at [/docs/llms.txt](/docs/llms.txt). Append `.md` to any page URL for markdown, or send `Accept: text/markdown`.

> **Alpha:** Early access SDK
>
> As an Alpha release, this SDK may contain bugs and cause crashes. Before you enable in production, thoroughly test your app in a controlled environment. For more information about best practices for developer preview SDKs, see [SDK Maintenance and Support](https://amplitude.com/docs/sdks/sdk-maintenance-and-support#sdk-major-version-life-cycle).

This article covers Session Replay installation through the [iOS SDK middleware](https://amplitude.com/docs/sdks/sdk-middleware). If your app already uses the [(maintenance) Amplitude SDK](https://amplitude.com/docs/sdks/analytics/ios/ios-sdk), use this option.

If your app already uses the [(latest) iOS Swift SDK](https://amplitude.com/docs/sdks/analytics/ios/ios-swift-sdk), choose the [Session Replay iOS SDK Plugin](https://amplitude.com/docs/sdks/session-replay/session-replay-ios-plugin).

If you use Segment through their Analytics-Swift SDK and [Amplitude (Actions) destination](https://segment.com/docs/connections/destinations/catalog/actions-amplitude/), choose the [Segment Plugin](https://amplitude.com/docs/sdks/session-replay/session-replay-ios-segment-integration).

If you use a provider other than Amplitude for in-product analytics, choose the [standalone implementation](https://amplitude.com/docs/sdks/session-replay/session-replay-ios-standalone-sdk).

> **Note:** Session Replay and performance
>
> Amplitude built Session Replay to minimize impact on the performance of the iOS apps in which it's installed by:
>
> - Asynchronously processing replay data, to avoid blocking the main user interface thread. The main thread must be used to interact with the view hierarchy, but all processing is performed on a background queue.
> - Using batching and lightweight compression to reduce the number of network connections and bandwidth.
> - Optimizing view hierarchy processing. Contact Amplitude if you experience issues with hierarchy processing.

## Before you begin

The Session Replay Middleware requires that:

1. Your application runs on iOS or iPadOS.
2. You use `8.22.0` or higher of the [(maintenance) Amplitude iOS SDK](https://amplitude.com/docs/sdks/analytics/ios/ios-sdk).
3. You can provide a device ID to the SDK.

### Supported iOS versions

Session Replay supports a minimum target version of iOS 13.

## Quickstart

Add the [latest version](https://github.com/amplitude/AmplitudeSessionReplay-iOS) of the middleware to your project dependencies.

#### SPM

Add Session Replay as a dependency in your Package.swift file, or the Package list in Xcode.

```swift
dependencies: [
    .package(url: "https://github.com/amplitude/AmplitudeSessionReplay-iOS", from: "0.12.8")
]
```

For integrating with `Amplitude-iOS`, use the `AmplitudeiOSSessionReplayMiddleware` target.

```swift
.product(name: "AmplitudeiOSSessionReplayMiddleware", package: "AmplitudeSessionReplay")
```

#### CocoaPods

Add the core library and the middleware to your Podfile.

```plaintext
pod 'AmplitudeSessionReplay', :git => 'https://github.com/amplitude/AmplitudeSessionReplay-iOS.git', :tag => 'v0.12.8'
pod 'AmplitudeiOSSessionReplayMiddleware', :git => 'https://github.com/amplitude/AmplitudeSessionReplay-iOS.git', :tag => 'v0.12.8'
```

Configure your application code:

```swift
import Amplitude
import AmplitudeiOSSessionReplayMiddleware

// Initialize Amplitude Analytics SDK instance

let amplitude = Amplitude.instance()

// Although not required, we recommend enabling session start and end events when enabling Session Replay
amplitude.defaultTracking.sessions = true

// Create and Install Session Replay Middleware
// Recording will be handled automatically
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(sampleRate: 0.1))

amplitude.initializeApiKey(API_KEY)
```

## Configuration

Pass the following options when you initialize the Session Replay middleware:

| Option | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `sampleRate` | `Float` | No | `0` | Controls how many sessions to select for replay collection. Use a decimal between 0 and 1, for example `0.4`, representing the fraction of sessions randomly selected for replay collection. Over a large number of sessions, `0.4` selects `40%` of those sessions. For more information, refer to [Sampling rate](#sampling-rate). |
| `enableRemoteConfig` | `Bool` | No | `true` | Enables or disables remote configuration for this instance of Session Replay. |
| `autoStart` | `Bool` | No | `true` | Controls whether Session Replay begins capturing automatically when it initializes. |
| `maskLevel` | `MaskLevel` | No | `.medium` | Sets how much on-screen content Session Replay masks. Use `.light`, `.medium`, or `.conservative`. For more detail, refer to [Mask level](#mask-level). |
| `captureWebViews` | `Bool` | No | `false` | Enables capture of web view content. By default, Session Replay blocks web views. |
| `webviewMappings` | `[String: String]` | No | `[:]` | Maps substrings in captured web view content to replacement values. When you enable `captureWebViews`, Session Replay applies each entry as a case-insensitive find-and-replace on the web view recording data before upload. This is an advanced option; most apps leave it empty. |
| `recordLogOptions.logCountThreshold` | `Int` | No | `1000` | Sets the maximum number of logs per session. |
| `recordLogOptions.maxMessageLength` | `Int` | No | `2000` | Sets the maximum length of a log message. |
| `quality` | `QualityProfile` | No | `.high` | Controls capture and encoding quality (for example, frame rate and image resolution). Use `.low`, `.medium`, or `.high` to balance replay fidelity with performance and storage. Use `QualityProfile.automatic` to let the SDK choose a profile based on the device. |
| `uploadConfig` | `UploadConfig` | No | `UploadConfig()` | Controls when Session Replay uploads data. Use `UploadConfig(disableMeteredUploads: true)` to pause uploads on metered networks (for example, cellular). |

### Block on-screen data

Session Replay supports three ways to block sensitive on-screen data. Masking setting for WebViews is in the [Web view support](#web-view-support-beta) section.

#### Mask level

Session Replay for iOS supports three levels of masking, configurable with the `maskLevel` option.

Use this option in the Session Replay configuration.

| Mask level | Description |
| --- | --- |
| `light` | Masks all passwords, email addresses, credit card numbers, and phone numbers. |
| `medium` | Masks all editable text views. |
| `conservative` | Masks all text views. |

#### Privacy methods for UIKit

Session Replay provides an extension on `UIView` to manage privacy. Import the Session Replay library to access it.

```swift
import AmplitudeSessionReplay
```

| Variable | Description |
| --- | --- |
| `amp_isBlocked` | Set `view.amp_isBlocked` to selectively replace a view and its subviews with a placeholder in session replays. UITextViews and UITextFields are automatically blocked. To unblock a view that is masked by default, set the this value to false |

#### Privacy Modifiers for SwiftUI

Session Replay provides an extension on `View` to manage privacy. Import the Session Replay Library to access it.

```swift
import AmplitudeSessionReplay
```

| Modifier | Description |
| --- | --- |
| `amp_setBlocked(_ blocked: Bool)` | Add the `amp_setBlocked()` modifier to a `View` to selectively replace a view and its subviews with a placeholder in session replays. To unblock a view that is masked by default, set the this value to false |

### User opt-out

The Session Replay middleware follows the Amplitude-iOS SDK's `optOut` setting and doesn't support user opt-outs on its own.

```swift
// Set optOut on the Amplitude SDK
amplitude.optOut = true
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(/* session replay options */))
```

### EU data residency

Session Replay is available to Amplitude Customers who use the EU data center. Set the `serverZone` configuration option to `EU` during initialization. For example:

```swift
// Set serverZone on the Amplitude SDK
amplitude.setServerZone(.EU)
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(/* session replay options */))
```

### Sampling rate

By default, Session Replay captures 0% of sessions for replay. Use your SDK's `sampleRate` configuration option to set the proportion of sessions to capture.

For manual and dynamic sampling, quota planning, and quota accounting, go to [Configure Session Replay sampling](https://amplitude.com/docs/session-replay/configure-sampling).

```swift
// This configuration samples 1% of all sessions
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(sampleRate: 0.01))
```

### Recording quality

Choose a quality profile to balance replay fidelity with performance and storage. Lower profiles use a lower capture frame rate and lower image resolution. Higher profiles use a higher frame rate and higher resolution. Use `QualityProfile.automatic` to let the SDK select a profile based on the device (for example, high on newer devices, lower on older ones).

```swift
// Use automatic profile selection based on device
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(
    sampleRate: 0.1,
    quality: .automatic
))

// Or set a fixed profile (low, medium, or high)
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(
    sampleRate: 0.1,
    quality: .medium
))
```

### Disable uploads on metered networks

Avoid using the user's cellular data by pausing Session Replay uploads while the device is on a metered network. Session Replay still records data locally. Uploads resume when the device reconnects to Wi‑Fi or another non-metered connection.

```swift
amplitude.addEventMiddleware(AmplitudeiOSSessionReplayMiddleware(
    sampleRate: 0.1,
    uploadConfig: UploadConfig(disableMeteredUploads: true)
))
```

### Disable replay collection

After it's enabled, Session Replay runs on your app until either:

- The user leaves your app.
- You call `sessionReplayMiddleware.stop()`.
- You remove the middleware from the SDK with `amplitude.removeEventMiddleware(sessionReplayMiddleware)`.

Call `sessionReplayMiddleware.stop()` before a user navigates to a restricted area of your app to disable replay collection while the user is in that area.

> **Note:** Keep a reference
>
> This requires keeping a reference to the Session Replay Middleware instance `let sessionReplayMiddleware = AmplitudeiOSSessionReplayMiddleware(/* session replay options */)`.

Call `sessionReplayMiddleware.start()` to re-enable replay collection when the user returns to an unrestricted area of your app.

To capture only specific screens, initialize the middleware with `autoStart: false` so it doesn't start on launch, then call `start()` and `stop()` as the user enters and leaves those screens:

```swift
// Add the middleware once, without starting capture
let sessionReplayMiddleware = AmplitudeiOSSessionReplayMiddleware(sampleRate: 1.0, autoStart: false)
amplitude.addEventMiddleware(sessionReplayMiddleware)

// Start capture when the user enters a screen you want to record
sessionReplayMiddleware.start()

// Stop capture when the user leaves that screen
sessionReplayMiddleware.stop()
```

You can also use a feature flag product like [Amplitude Experiment](https://amplitude.com/docs/feature-experiment/overview) to create logic that enables or disables replay collection based on criteria like location. For example, you can create a feature flag that targets a specific user group and add that to your initialization logic:

```swift
import Amplitude
import AmplitudeiOSSessionReplayMiddleware

// Your existing initialization logic with Amplitude-iOS SDK
let amplitude = Amplitude.instance()

if (nonEUCountryFlagEnabled) {
  // Create and Install Session Replay Middleware
  let sessionReplayMiddleware = AmplitudeiOSSessionReplayMiddleware(sampleRate: 0.1)
  amplitude.addEventMiddleware(sessionReplayMiddleware)
}

amplitude.initializeApiKey(API_KEY)
```

### Web view support (Beta)

By default, Session Replay blocks web views in a capture. To enable capture of all WebView components, set `captureWebViews` to `true` in the Session Replay configuration.

To mask specific WebView components, use the privacy methods described in [Block on-screen data](#block-on-screen-data).

```swift
// UIKit
webView.amp_isBlocked = false
```

### Map View Support (Alpha)

Session Replay supports capturing map views in iOS applications. To enable map view capture,  unmask the map view in your implementation.

```swift
// UIKit
mapView.amp_isBlocked = false

// SwiftUI
Map().amp_setBlocked(false)
```

### Log Recording

> **Note:** Availability
>
> AmplitudeSessionReplay `0.8.0` and later support log recording.

Session Replay supports recording logs in iOS applications. Configure the limits with `recordLogOptions` when you initialize the integration, then send log messages through `recordLog(level:message:date:)`.

#### swift

```swift
import AmplitudeSessionReplay

let sessionReplay = SessionReplay(
    apiKey: API_KEY,
    recordLogOptions: .init(logCountThreshold: 2000, maxMessageLength: 4000)
)

sessionReplay.recordLog(level: .error, message: "This is an error log")
```

#### swift

```swift
import AmplitudeSwiftSessionReplayPlugin

let sessionReplayPlugin = AmplitudeSwiftSessionReplayPlugin(recordLogOptions: .init(logCountThreshold: 2000, maxMessageLength: 4000))
amplitude.add(plugin: sessionReplayPlugin)

sessionReplayPlugin.recordLog(level: .error, message: "This is an error log")
```

#### swift

```swift
let sessionReplayMiddleware = AmplitudeiOSSessionReplayMiddleware(
    recordLogOptions: .init(logCountThreshold: 2000, maxMessageLength: 4000)
)
amplitude.addEventMiddleware(sessionReplayMiddleware)

sessionReplayMiddleware.recordLog(level: .error, message: "This is an error log")
```

#### swift

```swift
let sessionReplayPlugin = AmplitudeSegmentSessionReplayPlugin(
    amplitudeApiKey: API_KEY,
    recordLogOptions: .init(logCountThreshold: 2000, maxMessageLength: 4000)
)
analytics.add(plugin: sessionReplayPlugin)

sessionReplayPlugin.recordLog(level: .error, message: "This is an error log")
```

If you have implemented a log system, you can make single-point modifications to integrate log recording functionality. See the following examples for more information.

#### CocoaLumberjack

If you use `CocoaLumberjack`, you can integrate it with a custom logger provider.

```swift
class AmplitudeLogRecordLogger: DDAbstractLogger {

    private weak var plugin: SessionReplayPlugin?

    init(_ plugin: SessionReplayPlugin) {
        self.plugin = plugin
    }

    override func log(message logMessage: DDLogMessage) {
        let recordLevel: RecordLogLevel
        switch logMessage.flag {
        case .error:
            recordLevel = .error
        case .warning:
            recordLevel = .warn
        case .info:
            recordLevel = .log
        default:
            return
        }
        plugin?.recordLog(level: recordLevel,
                          message: logMessage.message,
                          date: logMessage.timestamp)
    }
}

let sessionReplayPlugin = AmplitudeSwiftSessionReplayPlugin()
amplitude.add(plugin: sessionReplayPlugin)

DDLog.add(AmplitudeLogRecordLogger(sessionReplayPlugin))

```

#### React Native

If you use `console` log or `react-native-logs` with `consoleTransport`, you can integrate it with `RCTAddLogFunction`.

```swift
RCTAddLogFunction { level, source, fileName, lineNumber, message in
  let recordLevel: RecordLogLevel
  switch level {
  case .error:
    recordLevel = .error
  case .warning:
    recordLevel = .warn
  case .info:
    recordLevel = .log
  case .fatal:
    recordLevel = .error
  case .trace:
    recordLevel = .init("trace")
  default:
    return
  }
  self.sessionReplayPlugin.recordLog(level: recordLevel, message: message)
}
```

## Data retention, deletion, and privacy

Review [consent guidance](https://amplitude.com/docs/session-replay/best-practices-for-managing-user-consent) when you implement capture.

### Retention period

For native and Flutter SDK retention guidance and the effective date of changes, go to the [Session Replay data lifecycle reference](https://amplitude.com/docs/session-replay/replay-data-lifecycle#native-and-flutter-sdk-retention).

### DSAR API

For replay metadata returned by the DSAR API, go to [Session Replay DSAR metadata](https://amplitude.com/docs/session-replay/replay-data-lifecycle#dsar-api).

### Data deletion

For user and project deletion behavior, go to [Session Replay data deletion](https://amplitude.com/docs/session-replay/replay-data-lifecycle#data-deletion).

### Bot filter

For bot filtering and property-filter restrictions, go to [Session Replay bot filtering](https://amplitude.com/docs/session-replay/replay-data-lifecycle#bot-filter).

## Session Replay storage

If a user opts out tracking in your app, use the `optOut` configuration option to disable replay collection for that user.

Session Replay temporarily stores replay data data on the file system before it is uploaded. At every initialization, the least recent replays are trimmed to bring the total disk usage down to a maximum size.

## Known limitations

Keep the following limitations in mind as you implement Session Replay:

- Session Replay doesn't stitch together replays from a single user across multiple projects. For example:

  - You instrument multiple apps as separate Amplitude projects with Session Replay enabled in each.
  - A known user begins on one app, and then switch to another.
  - Amplitude captures both sessions.
  - The replay for each session is available for view in the corresponding host project.
- The User Sessions chart doesn't show session replays if your organization uses a custom session definition.
- Session Replay cannot capture the following iOS views:

  - Out-of-process iOS views, such as SFSafariViewController
  - AVPlayerLayer backed views