Handling sensitive data

In order to protect user privacy, you can configure Smartlook to not record sensitive data.

Currently, there are three methods to handle sensitive data:

Rendering modes

The Smartlook SDK offers three rendering modes to create session recordings. Each rendering mode renders the app screen in a different way. The default rendering mode for the Smartlook SDK is Native (.native).


When using the Native rendering mode, the SDK can record sensitive data in your application.

The rendering modes available in the Smartlook SDK:

Rendering modeWhat is captured
.nativeRegularly captures the app screen which the SDK immediately processes to remove sensitive data. The frames are then complied to make the session recording. For more information, see View sensitivity.
.wireframeCaptures the app using only a wireframe representation of the screen data. No user data is recorded. This is the preferred rendering method for user data security.
.noRenderingNo content is recorded.

Setting the rendering mode

To set the rendering mode:

Smartlook.instance.preferences.renderingMode = .native

Reading the rendering mode

To see what rendering mode the SDK is using:

let renderingMode = Smartlook.instance.state.renderingMode

Wireframe rendering

You can use wireframe rendering to view how your users use your app, but not reveal any of the elements. This is the preferred method for user data safety.

Examples of wireframe rendering:

Example 1Example 2
Native rendering example 1Wireframe rendering example 1Native rendering example 2Wireframe rendering example 2


View sensitivity

You can set sensitivity to any UIView instance:

sampleView.slSensitive = true|false|nil

Smartlook.instance.sensitivity[someView] = true|false|nil

Class sensitivity

You can also set the sensitivity to all instances of a Class that extends a UIView rather than setting the sensitivity on a specific UIView:

Smartlook.instance.sensitivity[SomeViewSubclass.self] = true|false|nil


Default sensitive classes

By default, the UITextView, UITextField and WKWebView classes are set as sensitive. To override the sensitivity on the class or instance level, set the class or instance sensitivity to false or nil.

Protocol sensitivity

Smartlook provides two protocols, SensitiveData and NonSensitiveData that can be used to adjust class sensitivity.

Sensitivity prioritization

When determining if the UIView instance is sensitive, the resolution process checks the sensitivity in a strict order.

UIView instances are not recorded if:

  1. the sensitivity is set to true.
  2. the Class sensitivity is set to true.
  3. the class conforms NonSensitiveData protocol

Class hierarchy and sensitivity

The sensitivity set on descendants has a higher priority than the sensitivity set on the ancestors. For example, if we have a custom UITextView class descendant (class MyCustomTextView: UITextView) and mark it as non-sensitive, then MyCustomTextView and all its descendants will not be sensitive, no matter what sensitivity we set for UITextView.

Similarly, if we set the sensitivity on an ancestor class, all its descendants take over that sensitivity.


Rendering modes

The Smartlook SDK provides rendering modes that hide sensitive information by simplifying the rendered screen for recording. This is still useful to you because all user interactions are still recorded, but no sensitive data is rendered. For more information, see Rendering modes.


Automatically-detected touch events

Some screens display sensitive data through automatically detected touch events. Read more about this issue in secure custom keyboard example.

When the application no longer displays sensitive data, you can set screen rendering mode to NATIVE:

Smartlook.instance.preferences.renderingMode = .native

WebView sensitivity

If an app uses WKWebView and you want record them, you need to enable WKWebView recording. You can enable WKWebView recording by removing the sensitivity:

Smartlook.instance.sensitivity[WKWebView.self] = true

If WKWebView is being recorded, all sensitive elements on the displayed website should be marked as sensitive so that they are hidden. You can mark sensitive elements as sensitive using HTML elements with .smartlook-hide css class:

<div class='smartlook-hide'>
   This will be hidden.

All inputs are hidden by default except button and submit. If some hidden inputs should be recorded, they can be marked with .smartlook-show css class:

<input type="text" class='smartlook-show'>

Recording masks

In cases where areas of the app shouldn't be recorded, but cannot be defined by a UIview, you can use RecordingMask:

var maskElements = [MaskElement]()

maskElements.append(MaskElement(rect: CGRect(x: 0, y: 0, width: 100, height: 100), type: .covering))
maskElements.append(MaskElement(rect: CGRect(x: 50, y:120, width: 100, height: 100), type: .erasing))

let recordingMask = RecordingMask(elements: maskElements)

Smartlook.instance.recordingMask = recordingMask

You can only have one Recording mask set at a time, but the recording mask can contain a list of MaskElement to cover multiple areas at once.

MaskElement\ can be one of two types:

Mask typeHow it works
RecordingMask.Element.Type.COVERINGThe area defined by the element Rect is not recorded
RecordingMask.Element.Type.ERASINGThe area defined by the element Rect is recorded even if a previous RecordingMask.Element inside a list was covering the area.
  • MaskElement.MaskType.erasing – area defined by the element CGRect will be recorded even if a previously MaskElement was .covering this area.

RecordingMask example

The following example describes a RecordingMask in action.

On the left:

  • The blue box represents a video_item element.
  • The red box represents a video_item_image element.

On the right:

  • The video_item element (blue box) has a .COVERING value. The .COVERING value masks the element in the session recording.
  • The video_item_image element (red box) has an .ERASING value. The image is visible in the session recording because the .ERASING value cancels the .COVERING value.