diff --git a/backend/package.json b/backend/package.json
index 0f5c338..d8a17a4 100644
--- a/backend/package.json
+++ b/backend/package.json
@@ -6,7 +6,8 @@
   "scripts": {
     "dev": "DB_HOST=127.0.0.1 DB_PORT=3307 DB_USER=tier_cursor DB_PASSWORD=tier_cursor1234 DB_NAME=tier_cursor nodemon --legacy-watch --watch index.js --watch src index.js",
     "start": "DB_HOST=127.0.0.1 DB_PORT=3307 DB_USER=tier_cursor DB_PASSWORD=tier_cursor1234 DB_NAME=tier_cursor node index.js",
-    "images:backfill": "DB_HOST=127.0.0.1 DB_PORT=3307 DB_USER=tier_cursor DB_PASSWORD=tier_cursor1234 DB_NAME=tier_cursor node scripts/backfill-legacy-image-assets.js"
+    "images:backfill": "DB_HOST=127.0.0.1 DB_PORT=3307 DB_USER=tier_cursor DB_PASSWORD=tier_cursor1234 DB_NAME=tier_cursor node scripts/backfill-legacy-image-assets.js",
+    "images:migrate-legacy": "DB_HOST=127.0.0.1 DB_PORT=3307 DB_USER=tier_cursor DB_PASSWORD=tier_cursor1234 DB_NAME=tier_cursor node scripts/migrate-legacy-uploads-to-assets.js"
   },
   "keywords": [],
   "author": "",
diff --git a/backend/scripts/migrate-legacy-uploads-to-assets.js b/backend/scripts/migrate-legacy-uploads-to-assets.js
new file mode 100644
index 0000000..e274b4f
--- /dev/null
+++ b/backend/scripts/migrate-legacy-uploads-to-assets.js
@@ -0,0 +1,112 @@
+const fs = require('fs/promises')
+const path = require('path')
+const sharp = require('sharp')
+const {
+  ensureData,
+  closePool,
+  listReferencedUploadUsage,
+  replaceUploadSourceReferences,
+} = require('../src/db')
+const { writeOptimizedImage } = require('../src/lib/image-storage')
+
+const BACKEND_ROOT = path.join(__dirname, '..')
+
+function inferMimeType(src, metadata) {
+  const format = String(metadata?.format || '').toLowerCase()
+  if (format === 'jpeg' || format === 'jpg') return 'image/jpeg'
+  if (format === 'png') return 'image/png'
+  if (format === 'gif') return 'image/gif'
+  if (format === 'webp') return 'image/webp'
+  if (format === 'svg' || format === 'svg+xml') return 'image/svg+xml'
+  if (format === 'avif') return 'image/avif'
+
+  const ext = path.extname(src || '').toLowerCase()
+  if (ext === '.jpg' || ext === '.jpeg') return 'image/jpeg'
+  if (ext === '.png') return 'image/png'
+  if (ext === '.gif') return 'image/gif'
+  if (ext === '.webp') return 'image/webp'
+  if (ext === '.svg') return 'image/svg+xml'
+  if (ext === '.avif') return 'image/avif'
+  return 'application/octet-stream'
+}
+
+function getOptimizationConfig(roles) {
+  const roleSet = new Set(roles || [])
+  if (roleSet.has('avatar')) {
+    return { directory: 'avatars', width: 512, height: 512, fit: 'cover', quality: 82 }
+  }
+  if (roleSet.has('game-thumbnail') || roleSet.has('tierlist-thumbnail') || roleSet.has('template-thumbnail')) {
+    return { directory: 'legacy-thumbnails', width: 1280, height: 1280, fit: 'inside', quality: 84 }
+  }
+  return { directory: 'legacy-items', width: 512, height: 512, fit: 'inside', quality: 84 }
+}
+
+async function createFileLike(src) {
+  const absolutePath = path.join(BACKEND_ROOT, src.replace(/^\//, ''))
+  const [buffer, stat] = await Promise.all([fs.readFile(absolutePath), fs.stat(absolutePath)])
+  let metadata = {}
+  try {
+    metadata = await sharp(buffer, { failOn: 'none' }).metadata()
+  } catch (error) {
+    metadata = {}
+  }
+  return {
+    file: {
+      originalname: path.basename(src),
+      mimetype: inferMimeType(src, metadata),
+      size: Number(stat.size || 0),
+      buffer,
+    },
+    absolutePath,
+  }
+}
+
+async function main() {
+  await ensureData()
+  const usageEntries = await listReferencedUploadUsage()
+  const legacyEntries = usageEntries.filter((entry) => entry.src && entry.src.startsWith('/uploads/') && !entry.src.startsWith('/uploads/assets/'))
+
+  const summary = {
+    scanned: legacyEntries.length,
+    migrated: 0,
+    reusedAsset: 0,
+    unchanged: 0,
+    missingFiles: 0,
+    failed: 0,
+    updatedRows: 0,
+  }
+
+  for (const entry of legacyEntries) {
+    const config = getOptimizationConfig(entry.roles)
+    try {
+      const { file } = await createFileLike(entry.src)
+      const optimized = await writeOptimizedImage({ file, ...config })
+      if (optimized.src === entry.src) {
+        summary.unchanged += 1
+        continue
+      }
+      const replaced = await replaceUploadSourceReferences({ fromSrc: entry.src, toSrc: optimized.src })
+      summary.updatedRows += Number(replaced.updatedRows || 0)
+      if (optimized.reused) summary.reusedAsset += 1
+      else summary.migrated += 1
+    } catch (error) {
+      if (error?.code === 'ENOENT') {
+        summary.missingFiles += 1
+        continue
+      }
+      summary.failed += 1
+      console.error('[migrate-legacy-uploads-to-assets] failed:', entry.src, error?.message || error)
+    }
+  }
+
+  console.log(JSON.stringify(summary, null, 2))
+}
+
+main()
+  .catch((error) => {
+    console.error(error)
+    process.exitCode = 1
+  })
+  .finally(async () => {
+    await closePool()
+  })
diff --git a/backend/src/db.js b/backend/src/db.js
index 4e4f2ab..7eba86c 100644
--- a/backend/src/db.js
+++ b/backend/src/db.js
@@ -754,32 +754,116 @@ async function deleteImageAssets(ids) {
 }
 
 async function listReferencedUploadSources() {
-  const referencedSrcs = new Set()
+  const usage = await listReferencedUploadUsage()
+  return usage.map((entry) => entry.src)
+}
+
+async function listReferencedUploadUsage() {
+  const usageMap = new Map()
+  const addUsage = (src, role) => {
+    if (typeof src !== 'string' || !src.startsWith('/uploads/')) return
+    if (!usageMap.has(src)) usageMap.set(src, new Set())
+    usageMap.get(src).add(role)
+  }
+
   const [userRows, gameRows, gameItemRows, customItemRows, tierListRows, templateRequestRows] = await Promise.all([
     query("SELECT avatar_src FROM users WHERE avatar_src <> ''"),
     query("SELECT thumbnail_src FROM games WHERE thumbnail_src <> ''"),
     query("SELECT src FROM game_items WHERE src <> ''"),
     query("SELECT src FROM custom_items WHERE src <> ''"),
-    query("SELECT thumbnail_src, pool_json FROM tierlists"),
-    query("SELECT thumbnail_src_snapshot, items_json FROM template_requests"),
+    query("SELECT id, thumbnail_src, pool_json FROM tierlists"),
+    query("SELECT id, thumbnail_src_snapshot, items_json FROM template_requests"),
   ])
 
-  for (const row of userRows) if (row.avatar_src) referencedSrcs.add(row.avatar_src)
-  for (const row of gameRows) if (row.thumbnail_src) referencedSrcs.add(row.thumbnail_src)
-  for (const row of gameItemRows) if (row.src) referencedSrcs.add(row.src)
-  for (const row of customItemRows) if (row.src) referencedSrcs.add(row.src)
+  for (const row of userRows) addUsage(row.avatar_src, 'avatar')
+  for (const row of gameRows) addUsage(row.thumbnail_src, 'game-thumbnail')
+  for (const row of gameItemRows) addUsage(row.src, 'game-item')
+  for (const row of customItemRows) addUsage(row.src, 'custom-item')
 
   for (const row of tierListRows) {
-    if (row.thumbnail_src) referencedSrcs.add(row.thumbnail_src)
-    collectUploadSrcsFromItems(parseJson(row.pool_json, []), referencedSrcs)
+    addUsage(row.thumbnail_src, 'tierlist-thumbnail')
+    for (const item of parseJson(row.pool_json, [])) addUsage(item?.src, 'tierlist-pool')
   }
 
   for (const row of templateRequestRows) {
-    if (row.thumbnail_src_snapshot) referencedSrcs.add(row.thumbnail_src_snapshot)
-    collectUploadSrcsFromItems(parseJson(row.items_json, []), referencedSrcs)
+    addUsage(row.thumbnail_src_snapshot, 'template-thumbnail')
+    for (const item of parseJson(row.items_json, [])) addUsage(item?.src, 'template-item')
   }
 
-  return Array.from(referencedSrcs)
+  return Array.from(usageMap.entries())
+    .map(([src, roles]) => ({ src, roles: Array.from(roles).sort() }))
+    .sort((a, b) => a.src.localeCompare(b.src))
+}
+
+function replaceItemSrc(items, fromSrc, toSrc) {
+  let changed = false
+  const nextItems = (items || []).map((item) => {
+    if (item?.src !== fromSrc) return item
+    changed = true
+    return { ...item, src: toSrc }
+  })
+  return { changed, items: nextItems }
+}
+
+async function replaceUploadSourceReferences({ fromSrc, toSrc }) {
+  if (!fromSrc || !toSrc || fromSrc === toSrc) return { updatedRows: 0 }
+
+  const [userResult, gameResult, gameItemResult, customItemResult] = await Promise.all([
+    query('UPDATE users SET avatar_src = ? WHERE avatar_src = ?', [toSrc, fromSrc]),
+    query('UPDATE games SET thumbnail_src = ? WHERE thumbnail_src = ?', [toSrc, fromSrc]),
+    query('UPDATE game_items SET src = ? WHERE src = ?', [toSrc, fromSrc]),
+    query('UPDATE custom_items SET src = ? WHERE src = ?', [toSrc, fromSrc]),
+  ])
+
+  let updatedRows = Number(userResult.affectedRows || 0) + Number(gameResult.affectedRows || 0) + Number(gameItemResult.affectedRows || 0) + Number(customItemResult.affectedRows || 0)
+
+  const tierListRows = await query('SELECT id, thumbnail_src, pool_json FROM tierlists')
+  for (const row of tierListRows) {
+    let nextThumbnail = row.thumbnail_src
+    let changed = false
+    if (row.thumbnail_src === fromSrc) {
+      nextThumbnail = toSrc
+      changed = true
+    }
+
+    const replacedPool = replaceItemSrc(parseJson(row.pool_json, []), fromSrc, toSrc)
+    if (replacedPool.changed) changed = true
+
+    if (changed) {
+      await query('UPDATE tierlists SET thumbnail_src = ?, pool_json = ?, updated_at = ? WHERE id = ?', [
+        nextThumbnail || '',
+        serializeJson(replacedPool.items),
+        now(),
+        row.id,
+      ])
+      updatedRows += 1
+    }
+  }
+
+  const requestRows = await query('SELECT id, thumbnail_src_snapshot, items_json FROM template_requests')
+  for (const row of requestRows) {
+    let nextThumbnail = row.thumbnail_src_snapshot
+    let changed = false
+    if (row.thumbnail_src_snapshot === fromSrc) {
+      nextThumbnail = toSrc
+      changed = true
+    }
+
+    const replacedItems = replaceItemSrc(parseJson(row.items_json, []), fromSrc, toSrc)
+    if (replacedItems.changed) changed = true
+
+    if (changed) {
+      await query('UPDATE template_requests SET thumbnail_src_snapshot = ?, items_json = ?, updated_at = ? WHERE id = ?', [
+        nextThumbnail || '',
+        serializeJson(replacedItems.items),
+        now(),
+        row.id,
+      ])
+      updatedRows += 1
+    }
+  }
+
+  return { updatedRows }
 }
 
 async function listImageAssets() {
@@ -1788,6 +1872,8 @@ module.exports = {
   listUnusedImageAssets,
   deleteImageAssets,
   listReferencedUploadSources,
+  listReferencedUploadUsage,
+  replaceUploadSourceReferences,
   clearImageOptimizationJobs,
   getImageAssetStats,
   createGameItem,
diff --git a/docs/todo.md b/docs/todo.md
index 4eaa696..6f43c3d 100644
--- a/docs/todo.md
+++ b/docs/todo.md
@@ -1,7 +1,7 @@
 # 할 일 및 이슈
 
 ## 즉시 확인 필요
-- 레거시 업로드 메타 백필은 가능해졌으므로, 필요하면 다음 단계에서 실제 파일 경로까지 `/uploads/assets/` 기준으로 재정렬하는 마이그레이션을 검토한다.
+- 레거시 참조를 `/uploads/assets/`로 재정렬하는 마이그레이션 스크립트는 준비됐으므로, 운영 반영 후에는 더 이상 참조되지 않는 예전 업로드 파일을 안전하게 정리하는 후속 배치를 검토한다.
 - 관리자 기본 아이템 다중 업로드는 현재 파일명 기반 자동 라벨만 지원하므로, 필요하면 업로드 후 일괄 라벨 수정/정렬 UX를 추가 검토한다.
 - 사용자 커스텀 아이템 승격은 현재 수동 복제 방식이므로, 필요하면 중복 감지나 “비슷한 항목 추천” 같은 보조 UX를 검토한다.
 - 관리자 티어표 관리의 추가 아이템 승격은 현재 커스텀(origin=`custom`) 아이템 기준이므로, 필요하면 “기존 게임 아이템과 비교한 차집합” 기준으로 더 정교하게 확장할 수 있다.
diff --git a/docs/update.md b/docs/update.md
index c6ed6fa..999cfa3 100644
--- a/docs/update.md
+++ b/docs/update.md
@@ -1,5 +1,10 @@
 # 업데이트 로그
 
+## 2026-03-31 v1.3.7
+- 현재 참조 중인 레거시 업로드를 다시 최적화 자산 경로로 편입하고 DB 참조를 일괄 교체하는 1회 마이그레이션 스크립트를 추가함.
+- 아바타/썸네일/아이템 역할에 따라 기존 업로드를 512px 또는 1280px 규격으로 다시 정리해, 실제 참조 경로도 '/uploads/assets/' 체계에 점진적으로 수렴시킬 수 있게 함.
+- 루트와 백엔드에 레거시 마이그레이션 실행 스크립트를 연결하고, todo 문서도 다음 단계 기준으로 갱신함.
+
 ## 2026-03-31 v1.3.6
 - 현재 참조 중인 레거시 업로드 파일을 'image_assets' 메타에 안전하게 편입하는 1회 백필 스크립트를 추가해, 과거 이미지도 최적화 대시보드와 같은 통계 체계 안에서 집계할 수 있게 함.
 - 루트와 백엔드에 백필 실행 스크립트를 연결해 운영 중 필요할 때 즉시 재실행할 수 있도록 정리함.
diff --git a/package.json b/package.json
index 0929fad..21ae87a 100644
--- a/package.json
+++ b/package.json
@@ -9,7 +9,8 @@
     "build": "npm --prefix frontend run build",
     "start": "npm --prefix backend run start",
     "test": "echo \"Error: no test specified\" && exit 1",
-    "images:backfill": "npm --prefix backend run images:backfill"
+    "images:backfill": "npm --prefix backend run images:backfill",
+    "images:migrate-legacy": "npm --prefix backend run images:migrate-legacy"
   },
   "keywords": [],
   "author": "",