diff --git a/src/admin/class-admin.php b/src/admin/class-admin.php
index eb584e0..e46e357 100644
--- a/src/admin/class-admin.php
+++ b/src/admin/class-admin.php
@@ -118,6 +118,7 @@ public function register_settings() {
 					'show_in_rest'      => [
 						'schema' => [
 							'type' => 'object',
+							'additionalProperties' => true, // If we upgrade or downgrade, the settings can possibly show as null. Prevent this.
 							'properties' => [
 								// General settings
 								'optimize_all_media' => [
diff --git a/src/admin/class-script-loader.php b/src/admin/class-script-loader.php
index 8b67131..d04ef04 100644
--- a/src/admin/class-script-loader.php
+++ b/src/admin/class-script-loader.php
@@ -77,6 +77,10 @@ public static function enqueue_cimo_assets() {
 			// Get current settings
 			$settings = get_option( 'cimo_options', [] );
 
+			// Expose threshold for WP Core's big image scaling.
+			// Can be false when auto scaling is disabled.
+			$threshold = apply_filters( 'big_image_size_threshold', 2560 );
+
 			// Localize script with REST API URL, nonce, and settings
 			wp_localize_script(
 				'cimo-script',
@@ -100,6 +104,7 @@ public static function enqueue_cimo_assets() {
 					'svgUpload' => isset( $settings['svg_upload'] ) ? (int) $settings['svg_upload'] : 0,
 					'svgOptimizationEnabled' => isset( $settings['svg_optimization_enabled'] ) ? (int) $settings['svg_optimization_enabled'] : 1,
 					'stealthModeEnabled' => isset( $settings['stealth_mode_enabled'] ) ? (int) $settings['stealth_mode_enabled'] : 0,
+					'wpScalingThreshold' => $threshold,
 				]
 			);
 
diff --git a/src/admin/js/page/admin-settings.js b/src/admin/js/page/admin-settings.js
index 270f000..5ab23b2 100644
--- a/src/admin/js/page/admin-settings.js
+++ b/src/admin/js/page/admin-settings.js
@@ -591,8 +591,15 @@ const AdminSettings = () => {
 								label={ __( 'Maximum Image Dimension', 'cimo-image-optimizer' ) }
 								type="number"
 								value={ settings.maxImageDimension }
+								placeholder={ settings.disableWpScaling === 1 ? '2560' : undefined }
 								onChange={ value => handleInputChange( 'maxImageDimension', value ) }
-								help={ __( 'Maximum width or height in pixels for uploaded images. Images exceeding this dimension will be automatically resized while preserving aspect ratio. Leave empty to disable resizing. We recommend a value of 1920px.', 'cimo-image-optimizer' ) }
+								help={ sprintf(
+									__( 'Maximum width or height in pixels for uploaded images. Images exceeding this dimension will be automatically resized while preserving aspect ratio. Leave empty to %s. We recommend a value of 1920px.', 'cimo-image-optimizer' ),
+									window.cimoSettings?.wpScalingThreshold
+										? sprintf( __( "use WordPress's default auto-scaling at %spx", 'cimo-image-optimizer' ), window.cimoSettings.wpScalingThreshold )
+										: __( 'disable auto-scaling', 'cimo-image-optimizer' )
+								) }
+
 								__next40pxDefaultSize
 							/>
 						</div>
diff --git a/src/shared/converters/index.js b/src/shared/converters/index.js
index 7a58c50..b3769e3 100644
--- a/src/shared/converters/index.js
+++ b/src/shared/converters/index.js
@@ -38,6 +38,16 @@ export const getFileConverter = _file => {
 	}
 
 	if ( file.type.startsWith( 'image/' ) ) {
+		const max = parseFloat( window.cimoSettings?.maxImageDimension || 0 )
+		const wp = parseFloat( window.cimoSettings?.wpScalingThreshold || 0 )
+
+		// Determine the final max dimension to use for conversion,
+		// prioritizing the lower of the two thresholds if both are set.
+		// 0 means no max dimension.
+		const finalMaxDimension = max && wp
+			? Math.min( max, wp )
+			: max || wp || 0
+
 		// If the browser doesn't support webp, then we can't convert it.
 		if ( ! isFormatSupported( 'webp' ) ) {
 			return new NullConverter( file )
@@ -46,7 +56,7 @@ export const getFileConverter = _file => {
 			return new ImageConverter( file, {
 				format: 'webp',
 				quality: window.cimoSettings?.webpQuality || 0.8,
-				maxDimension: window.cimoSettings?.maxImageDimension || 0,
+				maxDimension: finalMaxDimension,
 			} )
 		}
 	}