diff --git a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
index 2974b99696..5ffd90b3ab 100644
--- a/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
+++ b/features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt
@@ -43,6 +43,7 @@ import io.element.android.features.messages.impl.timeline.TimelineController
 import io.element.android.features.messages.impl.utils.TextPillificationHelper
 import io.element.android.libraries.architecture.AsyncAction
 import io.element.android.libraries.architecture.Presenter
+import io.element.android.libraries.core.coroutine.CoroutineDispatchers
 import io.element.android.libraries.core.extensions.runCatchingExceptions
 import io.element.android.libraries.core.mimetype.MimeTypes
 import io.element.android.libraries.designsystem.utils.snackbar.SnackbarDispatcher
@@ -110,6 +111,7 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.merge
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import timber.log.Timber
 import kotlin.time.Duration.Companion.seconds
 import io.element.android.libraries.core.mimetype.MimeTypes.Any as AnyMimeTypes
@@ -145,6 +147,7 @@ class MessageComposerPresenter(
     private val featureFlagService: FeatureFlagService,
     private val contentScannerService: ContentScannerService,
     private val contentValidationCache: EventContentValidationCache,
+    private val dispatchers: CoroutineDispatchers,
 ) : Presenter<MessageComposerState> {
     @AssistedFactory
     interface Factory {
@@ -193,22 +196,22 @@ class MessageComposerPresenter(
             .collectAsState(initial = false)
 
         val galleryMediaPicker = mediaPickerProvider.registerGalleryPicker { uri, mimeType ->
-            handlePickedMedia(uri, mimeType)
+            localCoroutineScope.handlePickedMedia(uri, mimeType)
         }
         val galleryMultiMediaPicker = mediaPickerProvider.registerGalleryMultiPicker { uris ->
-            handlePickedMediaList(uris)
+            localCoroutineScope.handlePickedMediaList(uris)
         }
         val filesPicker = mediaPickerProvider.registerFileMultiPicker(AnyMimeTypes) { uris ->
-            handlePickedMediaList(uris, sendAsFile = true)
+            localCoroutineScope.handlePickedMediaList(uris, sendAsFile = true)
         }
         val fileSinglePicker = mediaPickerProvider.registerFilePicker(AnyMimeTypes) { uri, mimeType ->
-            handlePickedMedia(uri, mimeType ?: MimeTypes.OctetStream, sendAsFile = true)
+            localCoroutineScope.handlePickedMedia(uri, mimeType ?: MimeTypes.OctetStream, sendAsFile = true)
         }
         val cameraPhotoPicker = mediaPickerProvider.registerCameraPhotoPicker { uri ->
-            handlePickedMedia(uri, MimeTypes.Jpeg)
+            localCoroutineScope.handlePickedMedia(uri, MimeTypes.Jpeg)
         }
         val cameraVideoPicker = mediaPickerProvider.registerCameraVideoPicker { uri ->
-            handlePickedMedia(uri, MimeTypes.Mp4)
+            localCoroutineScope.handlePickedMedia(uri, MimeTypes.Mp4)
         }
         val isFullScreen = rememberSaveable {
             mutableStateOf(false)
@@ -286,17 +289,16 @@ class MessageComposerPresenter(
                 }
                 is MessageComposerEvent.SendUri -> {
                     val inReplyToEventId = (messageComposerContext.composerMode as? MessageComposerMode.Reply)?.eventId
-                    sessionCoroutineScope.sendAttachment(
-                        attachment = Attachment.Media(
-                            localMedia = localMediaFactory.createFromUri(
-                                uri = event.uri,
-                                mimeType = null,
-                                name = null,
-                                formattedFileSize = null
-                            ),
-                        ),
-                        inReplyToEventId = inReplyToEventId,
-                    )
+                    sessionCoroutineScope.launch {
+                        val localMedia = createLocalMedia(
+                            uri = event.uri,
+                            mimeType = null,
+                        )
+                        sendAttachment(
+                            attachment = Attachment.Media(localMedia),
+                            inReplyToEventId = inReplyToEventId,
+                        )
+                    }
 
                     resetComposerModeAfterAttaching()
                 }
@@ -640,17 +642,28 @@ class MessageComposerPresenter(
         }
     }
 
-    private fun handlePickedMedia(
-        uri: Uri?,
-        mimeType: String? = null,
-        sendAsFile: Boolean = false,
-    ) {
-        uri ?: return
-        val localMedia = localMediaFactory.createFromUri(
+    // Creating the LocalMedia queries the ContentResolver and can decode the media, so do it off the main thread
+    private suspend fun createLocalMedia(
+        uri: Uri,
+        mimeType: String?,
+    ) = withContext(dispatchers.io) {
+        localMediaFactory.createFromUri(
             uri = uri,
             mimeType = mimeType,
             name = null,
-            formattedFileSize = null
+            formattedFileSize = null,
+        )
+    }
+
+    private fun CoroutineScope.handlePickedMedia(
+        uri: Uri?,
+        mimeType: String? = null,
+        sendAsFile: Boolean = false,
+    ) = launch {
+        uri ?: return@launch
+        val localMedia = createLocalMedia(
+            uri = uri,
+            mimeType = mimeType,
         )
         val mediaAttachment = Attachment.Media(localMedia, sendAsFile = sendAsFile)
         val inReplyToEventId = (messageComposerContext.composerMode as? MessageComposerMode.Reply)?.eventId
@@ -659,7 +672,7 @@ class MessageComposerPresenter(
         resetComposerModeAfterAttaching()
     }
 
-    private fun handlePickedMediaList(
+    private fun CoroutineScope.handlePickedMediaList(
         uris: List<Uri>,
         sendAsFile: Boolean = false,
     ) {
@@ -668,19 +681,19 @@ class MessageComposerPresenter(
             handlePickedMedia(uris.first(), sendAsFile = sendAsFile)
             return
         }
-        val attachments = uris.map { uri ->
-            val localMedia = localMediaFactory.createFromUri(
-                uri = uri,
-                mimeType = null,
-                name = null,
-                formattedFileSize = null,
-            )
-            Attachment.Media(localMedia, sendAsFile = sendAsFile)
-        }.toImmutableList()
-        val inReplyToEventId = (messageComposerContext.composerMode as? MessageComposerMode.Reply)?.eventId
-        navigator.navigateToPreviewAttachments(attachments, inReplyToEventId)
+        launch {
+            val attachments = uris.map { uri ->
+                val localMedia = createLocalMedia(
+                    uri = uri,
+                    mimeType = null,
+                )
+                Attachment.Media(localMedia, sendAsFile = sendAsFile)
+            }.toImmutableList()
+            val inReplyToEventId = (messageComposerContext.composerMode as? MessageComposerMode.Reply)?.eventId
+            navigator.navigateToPreviewAttachments(attachments, inReplyToEventId)
 
-        resetComposerModeAfterAttaching()
+            resetComposerModeAfterAttaching()
+        }
     }
 
     private fun resetComposerModeAfterAttaching() {
diff --git a/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterSlashCommandTest.kt b/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterSlashCommandTest.kt
index a8f6c338f5..4535607cb6 100644
--- a/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterSlashCommandTest.kt
+++ b/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterSlashCommandTest.kt
@@ -324,6 +324,7 @@ class MessageComposerPresenterSlashCommandTest {
         featureFlagService = featureFlagService,
         contentScannerService = { _, _ -> },
         contentValidationCache = InMemoryEventContentValidationCache(),
+        dispatchers = testCoroutineDispatchers(useUnconfinedTestDispatcher = true),
     ).apply {
         isTesting = true
         showTextFormatting = isRichTextEditorEnabled
diff --git a/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterTest.kt b/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterTest.kt
index 3253e6088d..74b8047449 100644
--- a/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterTest.kt
+++ b/features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenterTest.kt
@@ -1723,6 +1723,7 @@ class MessageComposerPresenterTest : RobolectricTest() {
         featureFlagService = featureFlagService,
         contentScannerService = { _, _ -> },
         contentValidationCache = InMemoryEventContentValidationCache(),
+        dispatchers = testCoroutineDispatchers(useUnconfinedTestDispatcher = true),
     ).apply {
         isTesting = true
         showTextFormatting = isRichTextEditorEnabled