Screenshot Masking for Flutter

Measure captures screenshots on fatal erros, unhandled errors and bug reports. Before a screenshot leaves the device, sensitive content is redacted so it does not leak to the server.

On Flutter, masking traverses the widget tree under the MeasureWidget and paints over the regions that match the configured screenshot mask level.

Table of Contents

How Flutter Masking Works

Masking walks the widget tree under the MeasureWidget that wraps your app and collects the regions to redact:

  • Text — Text and RichText
  • Input fields — TextField and EditableText
  • Images — Image

Whether each region is masked depends on the active mask level. Two details are specific to Flutter:

  • Clickable detection is best-effort, based on the widget type. Text inside buttons, InkWell, or a GestureDetector with handlers is treated as clickable.
  • Sensitive detection treats a TextField as sensitive when obscureText is true, or when its keyboardType is emailAddress, phone, or visiblePassword. Sensitive fields are always masked, even at the all text except clickable level.

Mask Levels

The mask level is configured remotely from the dashboard and applies to all platforms. See Screenshot Mask Level for the full list of levels and what each one redacts.

Manual Masking

MsrMask Widget#

Automatic detection covers standard text, input and image widgets. To always mask anything else, wrap it with MsrMask. The wrapped widget's area is always redacted, regardless of the configured mask level.

MsrMask(
  child: AccountBalance(amount: balance),
)
Screenshot Masking for SwiftUIApp Launch Metrics