diff --git a/firebase-vertexai/CHANGELOG.md b/firebase-vertexai/CHANGELOG.md
index 62db530d71f..e922c2d9f65 100644
--- a/firebase-vertexai/CHANGELOG.md
+++ b/firebase-vertexai/CHANGELOG.md
@@ -1,7 +1,12 @@
 # Unreleased
 * [changed] Added new exception type for quota exceeded scenarios.
 * [feature] `CountTokenRequest` now includes `GenerationConfig` from the model.
-
+* [changed] **Breaking Change**: `ImagenInlineImage.data` now returns the raw
+  image bytes (in JPEG or PNG format, as specified in
+  `ImagenInlineImage.mimeType`) instead of Base64-encoded data. (#6800)
+    * **Action Required:** Remove any Base64 decoding from your
+      `ImagenInlineImage.data` usage.
+    * The `asBitmap()` helper method is unaffected and requires no code changes.
 
 # 16.2.0
 * [fixed] Added support for new values sent by the server for `FinishReason` and `BlockReason`.
diff --git a/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenGenerationResponse.kt b/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenGenerationResponse.kt
index dfc011b58f9..454f526bbee 100644
--- a/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenGenerationResponse.kt
+++ b/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenGenerationResponse.kt
@@ -16,6 +16,7 @@
 
 package com.google.firebase.vertexai.type
 
+import android.util.Base64
 import com.google.firebase.vertexai.ImagenModel
 import kotlinx.serialization.Serializable
 
@@ -53,7 +54,7 @@ internal constructor(public val images: List<T>, public val filteredReason: Stri
     val raiFilteredReason: String? = null,
   ) {
     internal fun toPublicInline() =
-      ImagenInlineImage(bytesBase64Encoded!!.toByteArray(), mimeType!!)
+      ImagenInlineImage(Base64.decode(bytesBase64Encoded!!, Base64.NO_WRAP), mimeType!!)
 
     internal fun toPublicGCS() = ImagenGCSImage(gcsUri!!, mimeType!!)
   }
diff --git a/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenInlineImage.kt b/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenInlineImage.kt
index 03e93abf8e7..1004f0a57ac 100644
--- a/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenInlineImage.kt
+++ b/firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/ImagenInlineImage.kt
@@ -18,13 +18,13 @@ package com.google.firebase.vertexai.type
 
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
-import android.util.Base64
 
 /**
- * Represents an Imagen-generated image that is contained inline
+ * Represents an Imagen-generated image that is returned as inline data.
  *
- * @param data Contains the raw bytes of the image
- * @param mimeType Contains the MIME type of the image (for example, `"image/png"`)
+ * @property data The raw image bytes in JPEG or PNG format, as specified by [mimeType].
+ * @property mimeType The IANA standard MIME type of the image data; either `"image/png"` or
+ * `"image/jpeg"`; to request a different format, see [ImagenGenerationConfig.imageFormat].
  */
 @PublicPreviewAPI
 public class ImagenInlineImage
@@ -34,7 +34,6 @@ internal constructor(public val data: ByteArray, public val mimeType: String) {
    * Returns the image as an Android OS native [Bitmap] so that it can be saved or sent to the UI.
    */
   public fun asBitmap(): Bitmap {
-    val data = Base64.decode(data, Base64.NO_WRAP)
     return BitmapFactory.decodeByteArray(data, 0, data.size)
   }
 }