diff --git a/quartz/build.ts b/quartz/build.ts
index 88447d2..1e4b745 100644
--- a/quartz/build.ts
+++ b/quartz/build.ts
@@ -18,22 +18,33 @@ import { trace } from "./util/trace"
 import { options } from "./util/sourcemap"
 import { Mutex } from "async-mutex"
 import sharp from "sharp"
+import { promises as fs } from 'fs';
 
 async function compressImages(inputDir, outputDir) {
   const files = await glob(`**/*.{jpg,png}`, inputDir);
 
   console.log(`Found ${files.length} files:`);
 
-  // Use sharp for image compression
   await Promise.all(
     files.map(async (file) => {
       const inputFilePath = path.join(inputDir, file);
       const relativeOutputPath = path.relative(inputDir, inputFilePath);
       const outputWebpPath = path.join(outputDir, relativeOutputPath.replace(/\.(jpg|png)$/, '.webp'));
 
-      await sharp(inputFilePath)
-        .webp({ quality: 75 })
-        .toFile(outputWebpPath);
+      try {
+        // Check if the output WebP file already exists
+        await fs.access(outputWebpPath);
+
+        // File exists, so skip compression
+        console.log(`Skipped: ${inputFilePath}`);
+      } catch (error) {
+        // File doesn't exist, proceed with compression
+        await sharp(inputFilePath)
+          .webp({ quality: 75 })
+          .toFile(outputWebpPath);
+
+        console.log(`Compressed: ${inputFilePath}`);
+      }
     })
   );