diff --git a/packages/vite/src/node/config.ts b/packages/vite/src/node/config.ts
index c78eb4f2346b05..c84a3516476293 100644
--- a/packages/vite/src/node/config.ts
+++ b/packages/vite/src/node/config.ts
@@ -1,4 +1,5 @@
 import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import { pathToFileURL } from 'node:url'
 import { performance } from 'node:perf_hooks'
@@ -1085,12 +1086,12 @@ async function loadConfigFromBundledFile(
       .slice(2)})}`
     const fileNameTmp = `${fileBase}.mjs`
     const fileUrl = `${pathToFileURL(fileBase)}.mjs`
-    fs.writeFileSync(fileNameTmp, bundledCode)
+    await fsp.writeFile(fileNameTmp, bundledCode)
     try {
       return (await dynamicImport(fileUrl)).default
     } finally {
       try {
-        fs.unlinkSync(fileNameTmp)
+        await fsp.unlink(fileNameTmp)
       } catch {
         // already removed if this function is called twice simultaneously
       }
@@ -1099,7 +1100,7 @@ async function loadConfigFromBundledFile(
   // for cjs, we can register a custom loader via `_require.extensions`
   else {
     const extension = path.extname(fileName)
-    const realFileName = fs.realpathSync(fileName)
+    const realFileName = await fsp.realpath(fileName)
     const loaderExt = extension in _require.extensions ? extension : '.js'
     const defaultLoader = _require.extensions[loaderExt]!
     _require.extensions[loaderExt] = (module: NodeModule, filename: string) => {
diff --git a/packages/vite/src/node/http.ts b/packages/vite/src/node/http.ts
index 7af73c899cccb2..88ccd4b955cdbc 100644
--- a/packages/vite/src/node/http.ts
+++ b/packages/vite/src/node/http.ts
@@ -1,4 +1,4 @@
-import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import type {
   Server as HttpServer,
@@ -124,23 +124,21 @@ export async function resolveHttpsConfig(
   https: boolean | HttpsServerOptions | undefined,
 ): Promise<HttpsServerOptions | undefined> {
   if (!https) return undefined
+  if (!isObject(https)) return {}
 
-  const httpsOption = isObject(https) ? { ...https } : {}
-
-  const { ca, cert, key, pfx } = httpsOption
-  Object.assign(httpsOption, {
-    ca: readFileIfExists(ca),
-    cert: readFileIfExists(cert),
-    key: readFileIfExists(key),
-    pfx: readFileIfExists(pfx),
-  })
-  return httpsOption
+  const [ca, cert, key, pfx] = await Promise.all([
+    readFileIfExists(https.ca),
+    readFileIfExists(https.cert),
+    readFileIfExists(https.key),
+    readFileIfExists(https.pfx),
+  ])
+  return { ...https, ca, cert, key, pfx }
 }
 
-function readFileIfExists(value?: string | Buffer | any[]) {
+async function readFileIfExists(value?: string | Buffer | any[]) {
   if (typeof value === 'string') {
     try {
-      return fs.readFileSync(path.resolve(value))
+      return fsp.readFile(path.resolve(value))
     } catch (e) {
       return value
     }
diff --git a/packages/vite/src/node/optimizer/index.ts b/packages/vite/src/node/optimizer/index.ts
index c9e189a5da18e6..580a6c8ceefba6 100644
--- a/packages/vite/src/node/optimizer/index.ts
+++ b/packages/vite/src/node/optimizer/index.ts
@@ -233,7 +233,7 @@ export async function optimizeDeps(
 
   const ssr = config.command === 'build' && !!config.build.ssr
 
-  const cachedMetadata = loadCachedDepOptimizationMetadata(
+  const cachedMetadata = await loadCachedDepOptimizationMetadata(
     config,
     ssr,
     force,
@@ -263,7 +263,7 @@ export async function optimizeServerSsrDeps(
   config: ResolvedConfig,
 ): Promise<DepOptimizationMetadata> {
   const ssr = true
-  const cachedMetadata = loadCachedDepOptimizationMetadata(
+  const cachedMetadata = await loadCachedDepOptimizationMetadata(
     config,
     ssr,
     config.optimizeDeps.force,
@@ -340,12 +340,12 @@ export function addOptimizedDepInfo(
  * Creates the initial dep optimization metadata, loading it from the deps cache
  * if it exists and pre-bundling isn't forced
  */
-export function loadCachedDepOptimizationMetadata(
+export async function loadCachedDepOptimizationMetadata(
   config: ResolvedConfig,
   ssr: boolean,
   force = config.optimizeDeps.force,
   asCommand = false,
-): DepOptimizationMetadata | undefined {
+): Promise<DepOptimizationMetadata | undefined> {
   const log = asCommand ? config.logger.info : debug
 
   // Before Vite 2.9, dependencies were cached in the root of the cacheDir
@@ -361,7 +361,7 @@ export function loadCachedDepOptimizationMetadata(
     try {
       const cachedMetadataPath = path.join(depsCacheDir, '_metadata.json')
       cachedMetadata = parseDepsOptimizerMetadata(
-        fs.readFileSync(cachedMetadataPath, 'utf-8'),
+        await fsp.readFile(cachedMetadataPath, 'utf-8'),
         depsCacheDir,
       )
     } catch (e) {}
@@ -377,7 +377,7 @@ export function loadCachedDepOptimizationMetadata(
   }
 
   // Start with a fresh cache
-  fs.rmSync(depsCacheDir, { recursive: true, force: true })
+  await fsp.rm(depsCacheDir, { recursive: true, force: true })
 }
 
 /**
@@ -508,7 +508,11 @@ export function runOptimizeDeps(
   const cleanUp = () => {
     if (!cleaned) {
       cleaned = true
-      fs.rmSync(processingCacheDir, { recursive: true, force: true })
+      // No need to wait, we can clean up in the background because temp folders
+      // are unique per run
+      fsp.rm(processingCacheDir, { recursive: true, force: true }).catch(() => {
+        // Ignore errors
+      })
     }
   }
   const createProcessingResult = () => ({
@@ -1114,7 +1118,7 @@ export async function extractExportsData(
   let parseResult: ReturnType<typeof parse>
   let usedJsxLoader = false
 
-  const entryContent = fs.readFileSync(filePath, 'utf-8')
+  const entryContent = await fsp.readFile(filePath, 'utf-8')
   try {
     parseResult = parse(entryContent)
   } catch {
diff --git a/packages/vite/src/node/optimizer/optimizer.ts b/packages/vite/src/node/optimizer/optimizer.ts
index 629f8b9b9ccd3a..9e016310709f8c 100644
--- a/packages/vite/src/node/optimizer/optimizer.ts
+++ b/packages/vite/src/node/optimizer/optimizer.ts
@@ -99,7 +99,7 @@ async function createDepsOptimizer(
 
   const sessionTimestamp = Date.now().toString()
 
-  const cachedMetadata = loadCachedDepOptimizationMetadata(config, ssr)
+  const cachedMetadata = await loadCachedDepOptimizationMetadata(config, ssr)
 
   let handle: NodeJS.Timeout | undefined
 
diff --git a/packages/vite/src/node/optimizer/scan.ts b/packages/vite/src/node/optimizer/scan.ts
index 7929b337b8a6e4..32f9b2b1f4b979 100644
--- a/packages/vite/src/node/optimizer/scan.ts
+++ b/packages/vite/src/node/optimizer/scan.ts
@@ -1,4 +1,5 @@
 import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import { performance } from 'node:perf_hooks'
 import glob from 'fast-glob'
@@ -363,7 +364,7 @@ function esbuildScanPlugin(
       build.onLoad(
         { filter: htmlTypesRE, namespace: 'html' },
         async ({ path }) => {
-          let raw = fs.readFileSync(path, 'utf-8')
+          let raw = await fsp.readFile(path, 'utf-8')
           // Avoid matching the content of the comment
           raw = raw.replace(commentRE, '<!---->')
           const isHtml = path.endsWith('.html')
@@ -576,7 +577,7 @@ function esbuildScanPlugin(
         let ext = path.extname(id).slice(1)
         if (ext === 'mjs') ext = 'js'
 
-        let contents = fs.readFileSync(id, 'utf-8')
+        let contents = await fsp.readFile(id, 'utf-8')
         if (ext.endsWith('x') && config.esbuild && config.esbuild.jsxInject) {
           contents = config.esbuild.jsxInject + `\n` + contents
         }
diff --git a/packages/vite/src/node/plugins/css.ts b/packages/vite/src/node/plugins/css.ts
index 2d1c070382b8bd..1ea8cba9c510d9 100644
--- a/packages/vite/src/node/plugins/css.ts
+++ b/packages/vite/src/node/plugins/css.ts
@@ -1,4 +1,5 @@
 import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import { createRequire } from 'node:module'
 import glob from 'fast-glob'
@@ -1675,7 +1676,7 @@ async function rebaseUrls(
     return { file }
   }
 
-  const content = fs.readFileSync(file, 'utf-8')
+  const content = await fsp.readFile(file, 'utf-8')
   // no url()
   const hasUrls = cssUrlRE.test(content)
   // data-uri() calls
@@ -1834,7 +1835,7 @@ function createViteLessPlugin(
           if (result && 'contents' in result) {
             contents = result.contents
           } else {
-            contents = fs.readFileSync(resolved, 'utf-8')
+            contents = await fsp.readFile(resolved, 'utf-8')
           }
           return {
             filename: path.resolve(resolved),
diff --git a/packages/vite/src/node/server/hmr.ts b/packages/vite/src/node/server/hmr.ts
index 454bccd0f83474..9e693566366c5d 100644
--- a/packages/vite/src/node/server/hmr.ts
+++ b/packages/vite/src/node/server/hmr.ts
@@ -1,4 +1,4 @@
-import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import type { Server } from 'node:http'
 import colors from 'picocolors'
@@ -494,14 +494,14 @@ function error(pos: number) {
 // change event and sometimes this can be too early and get an empty buffer.
 // Poll until the file's modified time has changed before reading again.
 async function readModifiedFile(file: string): Promise<string> {
-  const content = fs.readFileSync(file, 'utf-8')
+  const content = await fsp.readFile(file, 'utf-8')
   if (!content) {
-    const mtime = fs.statSync(file).mtimeMs
+    const mtime = (await fsp.stat(file)).mtimeMs
     await new Promise((r) => {
       let n = 0
       const poll = async () => {
         n++
-        const newMtime = fs.statSync(file).mtimeMs
+        const newMtime = (await fsp.stat(file)).mtimeMs
         if (newMtime !== mtime || n > 10) {
           r(0)
         } else {
@@ -510,7 +510,7 @@ async function readModifiedFile(file: string): Promise<string> {
       }
       setTimeout(poll, 10)
     })
-    return fs.readFileSync(file, 'utf-8')
+    return await fsp.readFile(file, 'utf-8')
   } else {
     return content
   }
diff --git a/packages/vite/src/node/server/middlewares/indexHtml.ts b/packages/vite/src/node/server/middlewares/indexHtml.ts
index 764f48d4ad9169..a673574fd85ed2 100644
--- a/packages/vite/src/node/server/middlewares/indexHtml.ts
+++ b/packages/vite/src/node/server/middlewares/indexHtml.ts
@@ -1,4 +1,5 @@
 import fs from 'node:fs'
+import fsp from 'node:fs/promises'
 import path from 'node:path'
 import MagicString from 'magic-string'
 import type { SourceMapInput } from 'rollup'
@@ -292,7 +293,7 @@ export function indexHtmlMiddleware(
       const filename = getHtmlFilename(url, server)
       if (fs.existsSync(filename)) {
         try {
-          let html = fs.readFileSync(filename, 'utf-8')
+          let html = await fsp.readFile(filename, 'utf-8')
           html = await server.transformIndexHtml(url, html, req.originalUrl)
           return send(req, res, html, 'html', {
             headers: server.config.server.headers,