diff --git a/package.json b/package.json
index eda0aaa44..946e5c67e 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,8 @@
     "dev": "pnpm -r --parallel --filter='./packages/*' run dev",
     "release": "tsx scripts/release.ts",
     "ci-publish": "tsx scripts/publishCI.ts",
-    "ci-docs": "pnpm build && pnpm docs-build"
+    "ci-docs": "pnpm build && pnpm docs-build",
+    "merge-changelog": "tsx scripts/mergeChangelog.ts"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",
diff --git a/scripts/mergeChangelog.ts b/scripts/mergeChangelog.ts
new file mode 100644
index 000000000..a1b2bf77a
--- /dev/null
+++ b/scripts/mergeChangelog.ts
@@ -0,0 +1,213 @@
+/**
+ * Merges prerelease (alpha/beta/rc) changelog entries into a single stable
+ * release section within a package's CHANGELOG.md.
+ *
+ * Usage:
+ *   pnpm merge-changelog <package> <version>
+ *
+ * Example:
+ *   pnpm merge-changelog vite 8.0.0
+ *
+ * This will find the `## [8.0.0]` header in packages/vite/CHANGELOG.md,
+ * collect all entries from its prerelease versions (e.g. 8.0.0-beta.1,
+ * 8.0.0-rc.0), deduplicate and reorder them by category, append a
+ * "Beta Changelogs" section with links to each prerelease's tagged
+ * changelog, and write the merged result back to the file.
+ */
+import { readFile, writeFile } from 'node:fs/promises'
+import path from 'node:path'
+
+const pkg = process.argv[2]
+const version = process.argv[3]
+
+if (!pkg || !version) {
+  console.error('Usage: pnpm merge-changelog <package> <version>')
+  process.exit(1)
+}
+
+const CATEGORY_ORDER = [
+  '### ⚠ BREAKING CHANGES',
+  '### Features',
+  '### Bug Fixes',
+  '### Performance Improvements',
+  '### Documentation',
+  '### Miscellaneous Chores',
+  '### Code Refactoring',
+  '### Tests',
+]
+
+function escapeRegex(str: string): string {
+  return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')
+}
+
+const versionHeaderRe = /^## (?:<small>)?\[/
+
+function findReleaseHeaderIndex(lines: string[], version: string): number {
+  const re = new RegExp(`^## (?:<small>)?\\[${escapeRegex(version)}\\]`)
+  const idx = lines.findIndex((l) => re.test(l))
+  if (idx === -1) {
+    console.error(`Could not find header for version ${version}`)
+    process.exit(1)
+  }
+  return idx
+}
+
+function findEndBoundary(
+  lines: string[],
+  startIdx: number,
+  version: string,
+): number {
+  const prereleaseRe = new RegExp(
+    `^## (?:<small>)?\\[${escapeRegex(version)}-(beta|alpha|rc)\\.\\d+\\]`,
+  )
+  for (let i = startIdx + 1; i < lines.length; i++) {
+    if (versionHeaderRe.test(lines[i]) && !prereleaseRe.test(lines[i])) {
+      return i
+    }
+  }
+  return lines.length
+}
+
+function parseCategories(releaseLines: string[]): Map<string, string[]> {
+  const categories = new Map<string, string[]>()
+  let currentCategory: string | null = null
+
+  for (let i = 1; i < releaseLines.length; i++) {
+    const line = releaseLines[i]
+    if (versionHeaderRe.test(line)) {
+      currentCategory = null
+      continue
+    }
+    if (line.startsWith('### ')) {
+      currentCategory = line.trim()
+      if (!categories.has(currentCategory)) {
+        categories.set(currentCategory, [])
+      }
+      continue
+    }
+
+    if (currentCategory && line.trim() !== '') {
+      categories.get(currentCategory)!.push(line)
+    }
+  }
+
+  return categories
+}
+
+function findPreviousStableVersion(lines: string[], startIdx: number): string {
+  for (let i = startIdx; i < lines.length; i++) {
+    const match = lines[i].match(/^## (?:<small>)?\[([^\]]+)\]/)
+    if (match) {
+      const v = match[1]
+      if (!/alpha|beta|rc/.test(v)) {
+        return v
+      }
+    }
+  }
+  return ''
+}
+
+function updateHeaderCompareLink(
+  headerLine: string,
+  prevStable: string,
+  pkg: string,
+  version: string,
+): string {
+  if (!prevStable) return headerLine
+  const tagPrefix = pkg === 'vite' ? 'v' : `${pkg}@`
+  return headerLine.replace(
+    /compare\/[^)]+/,
+    `compare/${tagPrefix}${prevStable}...${tagPrefix}${version}`,
+  )
+}
+
+function collectPrereleaseHeaders(
+  releaseLines: string[],
+  pkg: string,
+): string[] {
+  const lines: string[] = []
+  for (const line of releaseLines) {
+    const match = line.match(
+      /^## (?:<small>)?\[([^\]]+)\]\(([^)]+)\)(?: \((\d{4}-\d{2}-\d{2})\))?/,
+    )
+    if (!match) continue
+    const [, ver, compareUrl, date] = match
+    if (!/alpha|beta|rc/.test(ver)) continue
+
+    const tagPrefix = pkg === 'vite' ? 'v' : `${pkg}@`
+    const tag = `${tagPrefix}${ver}`
+    const header = date
+      ? `#### [${ver}](${compareUrl}) (${date})`
+      : `#### [${ver}](${compareUrl})`
+    lines.push(
+      header,
+      '',
+      `See [${ver} changelog](https://github.com/vitejs/vite/blob/${tag}/packages/${pkg}/CHANGELOG.md)`,
+      '',
+    )
+  }
+  return lines
+}
+
+function buildOutputLines(
+  headerLine: string,
+  categories: Map<string, string[]>,
+  prereleaseLines: string[],
+): string[] {
+  const hasUnknownCategories = [...categories.keys()].filter(
+    (c) => !CATEGORY_ORDER.includes(c),
+  )
+  if (hasUnknownCategories.length > 0) {
+    throw new Error(
+      `Unknown categories found: ${hasUnknownCategories.join(', ')}`,
+    )
+  }
+
+  const outputLines: string[] = [headerLine, '']
+  for (const category of CATEGORY_ORDER) {
+    const items = categories.get(category)
+    if (items && items.length > 0) {
+      outputLines.push(category, '')
+      outputLines.push(...items)
+      outputLines.push('')
+    }
+  }
+
+  if (prereleaseLines.length > 0) {
+    outputLines.push('### Beta Changelogs', '', ...prereleaseLines)
+  }
+
+  return outputLines
+}
+
+const filePath = path.resolve(
+  // eslint-disable-next-line n/no-unsupported-features/node-builtins
+  import.meta.dirname,
+  `../packages/${pkg}/CHANGELOG.md`,
+)
+const content = await readFile(filePath, 'utf-8')
+const lines = content.split('\n')
+
+const releaseHeaderIdx = findReleaseHeaderIndex(lines, version)
+const endIdx = findEndBoundary(lines, releaseHeaderIdx, version)
+const releaseLines = lines.slice(releaseHeaderIdx, endIdx)
+
+const categories = parseCategories(releaseLines)
+const prereleaseLines = collectPrereleaseHeaders(releaseLines, pkg)
+const prevStable = findPreviousStableVersion(lines, endIdx)
+const headerLine = updateHeaderCompareLink(
+  releaseLines[0],
+  prevStable,
+  pkg,
+  version,
+)
+const outputLines = buildOutputLines(headerLine, categories, prereleaseLines)
+
+const result = [
+  ...lines.slice(0, releaseHeaderIdx),
+  ...outputLines,
+  ...lines.slice(endIdx),
+].join('\n')
+
+await writeFile(filePath, result, 'utf-8')
+console.log(`Merged prerelease changelog sections for ${version} in ${pkg}`)