diff --git a/locales/en-US.yml b/locales/en-US.yml
index 9c02e83021..faa7f5e59e 100644
--- a/locales/en-US.yml
+++ b/locales/en-US.yml
@@ -3194,6 +3194,7 @@ _imageEffector:
     mirror: "Mirror"
     invert: "Invert Colors"
     grayscale: "Grayscale"
+    blur: "Blur"
     colorAdjust: "Color Correction"
     colorClamp: "Color Compression"
     colorClampAdvanced: "Color Compression (Advanced)"
@@ -3209,6 +3210,8 @@ _imageEffector:
     angle: "Angle"
     scale: "Size"
     size: "Size"
+    radius: "Radius"
+    samples: "Samples"
     color: "Color"
     opacity: "Opacity"
     normalize: "Normalize"
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 4ae52990e5..16d1fe0ac6 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -3306,6 +3306,7 @@ _imageEffector:
     mirror: "ミラー"
     invert: "色の反転"
     grayscale: "白黒"
+    blur: "ぼかし"
     colorAdjust: "色調補正"
     colorClamp: "色の圧縮"
     colorClampAdvanced: "色の圧縮(高度)"
@@ -3323,6 +3324,8 @@ _imageEffector:
     angle: "角度"
     scale: "サイズ"
     size: "サイズ"
+    radius: "半径"
+    samples: "サンプル数"
     offset: "位置"
     color: "色"
     opacity: "不透明度"
diff --git a/packages/frontend/src/utility/image-effector/fxs.ts b/packages/frontend/src/utility/image-effector/fxs.ts
index 43e10a22fc..b954bd370d 100644
--- a/packages/frontend/src/utility/image-effector/fxs.ts
+++ b/packages/frontend/src/utility/image-effector/fxs.ts
@@ -3,6 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+import { FX_blur } from './fxs/blur.js';
 import { FX_checker } from './fxs/checker.js';
 import { FX_chromaticAberration } from './fxs/chromaticAberration.js';
 import { FX_colorAdjust } from './fxs/colorAdjust.js';
@@ -25,6 +26,7 @@ export const FXS = [
 	FX_mirror,
 	FX_invert,
 	FX_grayscale,
+	FX_blur,
 	FX_colorAdjust,
 	FX_colorClamp,
 	FX_colorClampAdvanced,
diff --git a/packages/frontend/src/utility/image-effector/fxs/blur.ts b/packages/frontend/src/utility/image-effector/fxs/blur.ts
new file mode 100644
index 0000000000..1e78df16b8
--- /dev/null
+++ b/packages/frontend/src/utility/image-effector/fxs/blur.ts
@@ -0,0 +1,77 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { defineImageEffectorFx } from '../ImageEffector.js';
+import { i18n } from '@/i18n.js';
+
+const shader = `#version 300 es
+precision mediump float;
+
+in vec2 in_uv;
+uniform sampler2D in_texture;
+uniform vec2 in_resolution;
+uniform float u_radius;
+uniform int u_samples;
+out vec4 out_color;
+
+void main() {
+	vec2 texelSize = 1.0 / in_resolution;
+	vec4 result = vec4(0.0);
+	float totalSamples = 0.0;
+	
+	// Simple box blur with configurable sample count
+	// Based on the original cross pattern but with more samples
+	int samples = min(u_samples, 128);
+	float radius = u_radius;
+	
+	// Calculate how many samples to take in each direction
+	int sampleRadius = int(sqrt(float(samples)) / 2.0);
+	
+	// Sample in a grid pattern around the center
+	for (int x = -sampleRadius; x <= sampleRadius; x++) {
+		for (int y = -sampleRadius; y <= sampleRadius; y++) {
+			vec2 offset = vec2(float(x), float(y)) * texelSize * radius;
+			vec2 sampleUV = in_uv + offset;
+			
+			// Only sample if within texture bounds
+			if (sampleUV.x >= 0.0 && sampleUV.x <= 1.0 && sampleUV.y >= 0.0 && sampleUV.y <= 1.0) {
+				result += texture(in_texture, sampleUV);
+				totalSamples += 1.0;
+			}
+		}
+	}
+	
+	out_color = totalSamples > 0.0 ? result / totalSamples : texture(in_texture, in_uv);
+}
+`;
+
+export const FX_blur = defineImageEffectorFx({
+	id: 'blur',
+	name: i18n.ts._imageEffector._fxs.blur,
+	shader,
+	uniforms: ['radius', 'samples'] as const,
+	params: {
+		radius: {
+			label: i18n.ts._imageEffector._fxProps.radius,
+			type: 'number',
+			default: 3.0,
+			min: 0.0,
+			max: 15.0,
+			step: 0.5,
+		},
+		samples: {
+			label: i18n.ts._imageEffector._fxProps.samples,
+			type: 'number',
+			default: 64,
+			min: 9,
+			max: 128,
+			step: 1,
+		},
+	},
+	main: ({ gl, u, params }) => {
+		gl.uniform1f(u.radius, params.radius);
+		gl.uniform1i(u.samples, params.samples);
+	},
+});
\ No newline at end of file