diff --git a/packages/frontend/src/scripts/upload/compress-config.ts b/packages/frontend/src/scripts/upload/compress-config.ts
index 3046b7f51..98f326f76 100644
--- a/packages/frontend/src/scripts/upload/compress-config.ts
+++ b/packages/frontend/src/scripts/upload/compress-config.ts
@@ -8,15 +8,15 @@ import { isWebpSupported } from './isWebpSupported.js';
 import type { BrowserImageResizerConfigWithConvertedOutput } from '@misskey-dev/browser-image-resizer';
 
 const compressTypeMap = {
-	'image/jpeg': { quality: 0.90, mimeType: 'image/webp' },
-	'image/png': { quality: 1, mimeType: 'image/webp' },
-	'image/webp': { quality: 0.90, mimeType: 'image/webp' },
+	'image/jpeg': { quality: 0.85, mimeType: 'image/webp' },
+	'image/png': { quality: 0.90, mimeType: 'image/webp' },
+	'image/webp': { quality: 0.85, mimeType: 'image/webp' },
 	'image/svg+xml': { quality: 1, mimeType: 'image/webp' },
 } as const;
 
 const compressTypeMapFallback = {
 	'image/jpeg': { quality: 0.85, mimeType: 'image/jpeg' },
-	'image/png': { quality: 1, mimeType: 'image/png' },
+	'image/png': { quality: 0.90, mimeType: 'image/png' },
 	'image/webp': { quality: 0.85, mimeType: 'image/jpeg' },
 	'image/svg+xml': { quality: 1, mimeType: 'image/png' },
 } as const;