Troubleshooting

Nothing draws

• The view has no size. SignatureInk has no intrinsic height. Give it a height or flex: 1 inside a parent that has a size.
• pencilOnly is on. Fingers are ignored on both platforms. On Android the stylus eraser end is ignored too.
• The ink matches the background. The default pen is black (iOS) or #111111 (Android) and does not follow dark mode. Set penColor for dark backgrounds. See Dark backgrounds.
• The New Architecture is off. The library ships a Fabric component only. See Installation.

Toolbar icons are invisible on Android

Without toolbarTintColor, Android draws save, share, download, check and the "…" overflow button in white. Set toolbarTintColor (or tintColor per button) to a color that contrasts with your background. See Toolbar colors.

Overflow menu shows "undo" in lowercase

Menu entries use accessibilityLabel, which falls back to text and then to id. Give items that may overflow a text or an accessibilityLabel:

toolbarButtons={[{ id: 'undo', accessibilityLabel: 'Undo' }]}

"SignatureInk: native view is not mounted yet"

A Promise method (toBase64, toFile, toSvg, getStrokeData, isEmpty, saveToPhotoLibrary) was called before the native view existed. Call it from an event handler or after the component has mounted, and use optional chaining on the ref.

"SignatureInk unmounted"

The component unmounted while a Promise method was still waiting for the native side, for example when the user navigated away during an export. Pending calls are rejected so they never hang. Catch the error, or ignore it if the screen is gone anyway.

"Failed to encode image" or "Failed to render bitmap"

The native side could not produce an image. On Android this happens when the view has not been laid out yet (zero size). Make sure the view is visible and has a size before you export.

saveToPhotoLibrary

• The iOS app crashes on save. NSPhotoLibraryAddUsageDescription is missing from Info.plist. iOS terminates apps that ask for photo access without it.
• It resolves with granted: false on iOS. The user denied access earlier. iOS will not ask again; send the user to Settings with Linking.openSettings().
• It rejects on Android 9 and older. Writing to the gallery needs WRITE_EXTERNAL_STORAGE there. Declare it with android:maxSdkVersion="28" and request it with PermissionsAndroid before saving.
• The saved PNG has a black background in the gallery (Android). The PNG is transparent when backgroundColor is not set, and some gallery apps show transparency as black. Set backgroundColor or use format: 'jpeg'. See Backgrounds.

Exports look different on iOS and Android

Most of this is by design. PNGs are always transparent on iOS but include backgroundColor on Android, trim margins differ, and SVG units are points on iOS and pixels on Android. The full list is on iOS vs Android.

Restored strokes have the wrong color

Stroke data does not store colors. setStrokeData() draws with the current penColor (and on Android the current pen widths). Set those props before restoring. See Restoring.

Strokes disappear after an interrupted replay

If the user draws, or you call undo(), redo(), clear() or setStrokeData() during replay(), only the strokes revealed so far are kept. Save the stroke data before replaying and restore it if needed. See Interrupting.

Undo behaves differently on Android

On Android undo() only removes strokes: clear() cannot be undone, and after setStrokeData() undo removes the restored strokes one at a time. iOS treats clear() and setStrokeData() as undoable steps. See History.

The ink type has no effect

defaultInkType is iOS only. monoline, fountainPen, watercolor and crayon need iOS 17; earlier versions fall back to pen.

Build errors after upgrading

The native code is generated from the TypeScript spec. After upgrading, run pod install in ios/, rebuild the native app, and on Android run ./gradlew clean if generated files look stale. In Expo, run npx expo prebuild --clean and rebuild. Expo Go is not supported.

Still stuck?

Open an issue on GitHub with your React Native version, platform and OS version, and a minimal snippet. Trying the example app from the repository first often shows whether the problem is in the library or in the surrounding layout.