diff --git a/backend/src/test/java/com/recipeapp/recipe/ImageCompressorTest.java b/backend/src/test/java/com/recipeapp/recipe/ImageCompressorTest.java
index 8d2c7c5..c9f1522 100644
--- a/backend/src/test/java/com/recipeapp/recipe/ImageCompressorTest.java
+++ b/backend/src/test/java/com/recipeapp/recipe/ImageCompressorTest.java
@@ -80,6 +80,17 @@ class ImageCompressorTest {
         assertThat(compressor.compressToPreview("data:image/jpeg;base64,!!!not-valid!!!")).isNull();
     }
 
+    @Test
+    void compressToPreview_acceptsJpegInput() throws Exception {
+        String dataUri = makeJpegDataUri(800, 600);
+        String result = compressor.compressToPreview(dataUri);
+        assertThat(result).startsWith("data:image/jpeg;base64,");
+        String base64 = result.substring("data:image/jpeg;base64,".length());
+        BufferedImage img = ImageIO.read(new ByteArrayInputStream(Base64.getDecoder().decode(base64)));
+        assertThat(img).isNotNull();
+        assertThat(img.getWidth()).isLessThanOrEqualTo(400);
+    }
+
     // ── helpers ──
 
     private String makePngDataUri(int width, int height) throws Exception {
@@ -95,4 +106,15 @@ class ImageCompressorTest {
         ImageIO.write(img, "png", bos);
         return "data:image/png;base64," + Base64.getEncoder().encodeToString(bos.toByteArray());
     }
+
+    private String makeJpegDataUri(int width, int height) throws Exception {
+        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
+        java.awt.Graphics2D g = img.createGraphics();
+        g.setColor(java.awt.Color.ORANGE);
+        g.fillRect(0, 0, width, height);
+        g.dispose();
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        ImageIO.write(img, "jpeg", bos);
+        return "data:image/jpeg;base64," + Base64.getEncoder().encodeToString(bos.toByteArray());
+    }
 }