diff --git a/demo/benchmark.ts b/demo/benchmark.ts
index 2859e8a..76b02da 100644
--- a/demo/benchmark.ts
+++ b/demo/benchmark.ts
@@ -21,11 +21,17 @@ const writeData = Array(1000)
 
 let startTime = performance.now();
 let testFileHandle = await root.getFileHandle(fileName, { create: true });
-const writer1 = await testFileHandle.createWritable();
-for (const d of writeData) {
-  await writer1.write(d);
+if (testFileHandle.createWritable == null) {
+  updateCost('built-in-writer-cost', true);
+} else {
+  const writer1 = await testFileHandle.createWritable();
+  for (const d of writeData) {
+    await writer1.write(d);
+  }
+  updateCost('built-in-writer-cost');
+  await writer1.truncate(0);
+  await writer1.close();
 }
-updateCost('built-in-writer-cost');
 
 startTime = performance.now();
 let tx = db.transaction('data', 'readwrite');
@@ -37,9 +43,6 @@ for (const d of writeData) {
 await tx.done;
 updateCost('indexeddb-write-cost');
 
-await writer1.truncate(0);
-await writer1.close();
-
 startTime = performance.now();
 const writer2 = await file(fileName).createWriter();
 for (const d of writeData) {
@@ -97,8 +100,12 @@ updateCost('opfs-tools-read-all-cost');
 
 getElById('status').remove();
 
-function updateCost(id: string) {
-  getElById(id).textContent = `${~~(performance.now() - startTime)}ms`;
+function updateCost(id: string, unsupported = false) {
+  if (unsupported) {
+    getElById(id).textContent = 'unsupported';
+  } else {
+    getElById(id).textContent = `${~~(performance.now() - startTime)}ms`;
+  }
 }
 
 // clear
diff --git a/src/access-worker.ts b/src/access-worker.ts
index 5f6ecaf..4c38815 100644
--- a/src/access-worker.ts
+++ b/src/access-worker.ts
@@ -1,11 +1,5 @@
-interface FileSystemSyncAccessHandle {
-  read: (container: ArrayBuffer, opts: { at: number }) => number;
-  write: (data: ArrayBuffer | ArrayBufferView, opts?: { at: number }) => number;
-  flush: () => void;
-  close: () => void;
-  truncate: (newSize: number) => void;
-  getSize: () => number;
-}
+import { FileSystemSyncAccessHandle } from './common';
+import OPFSWorker from './opfs-worker?worker&inline';
 
 type Async<F> = F extends (...args: infer Params) => infer R
   ? (...args: Params) => Promise<R>
@@ -21,11 +15,10 @@ export type OPFSWorkerAccessHandle = {
 };
 
 export async function createOPFSAccess(
-  filePath: string,
-  fileHandle: FileSystemFileHandle
+  filePath: string
 ): Promise<OPFSWorkerAccessHandle> {
   const postMsg = getWorkerMsger();
-  await postMsg('register', { filePath, fileHandle });
+  await postMsg('register', { filePath });
   return {
     read: async (offset, size) =>
       (await postMsg('read', {
@@ -78,9 +71,7 @@ function getWorkerMsger() {
   }
 
   function create() {
-    const blob = new Blob([`(${opfsWorkerSetupStr})()`]);
-    const url = URL.createObjectURL(blob);
-    const worker = new Worker(url);
+    const worker = new OPFSWorker();
 
     let cbId = 0;
     let cbFns: Record<number, { resolve: Function; reject: Function }> = {};
@@ -126,61 +117,3 @@ function getWorkerMsger() {
     };
   }
 }
-
-const opfsWorkerSetupStr = ((): void => {
-  const fileAccesserMap: Record<string, FileSystemSyncAccessHandle> = {};
-
-  self.onmessage = async (e) => {
-    const { evtType, args } = e.data;
-
-    let accessHandle = fileAccesserMap[args.filePath];
-
-    try {
-      let returnVal;
-      const trans: Transferable[] = [];
-      if (evtType === 'register') {
-        accessHandle = await args.fileHandle.createSyncAccessHandle();
-        fileAccesserMap[args.filePath] = accessHandle;
-      } else if (evtType === 'close') {
-        accessHandle.close();
-        delete fileAccesserMap[args.filePath];
-      } else if (evtType === 'truncate') {
-        accessHandle.truncate(args.newSize);
-      } else if (evtType === 'write') {
-        const { data, opts } = e.data.args;
-        returnVal = accessHandle.write(data, opts);
-      } else if (evtType === 'read') {
-        const { offset, size } = e.data.args;
-        const buf = new ArrayBuffer(size);
-        const readLen = accessHandle.read(buf, { at: offset });
-        returnVal =
-          readLen === size
-            ? buf
-            : // @ts-expect-error transfer support by chrome 114
-              buf.transfer?.(readLen) ?? buf.slice(0, readLen);
-        trans.push(returnVal);
-      } else if (evtType === 'getSize') {
-        returnVal = accessHandle.getSize();
-      } else if (evtType === 'flush') {
-        accessHandle.flush();
-      }
-
-      self.postMessage(
-        {
-          evtType: 'callback',
-          cbId: e.data.cbId,
-          returnVal,
-        },
-        // @ts-expect-error
-        trans
-      );
-    } catch (error) {
-      const err = error as Error;
-      self.postMessage({
-        evtType: 'throwError',
-        cbId: e.data.cbId,
-        errMsg: err.name + ': ' + err.message + '\n' + JSON.stringify(e.data),
-      });
-    }
-  };
-}).toString();
diff --git a/src/common.ts b/src/common.ts
index 379bfe7..92f89aa 100644
--- a/src/common.ts
+++ b/src/common.ts
@@ -1,3 +1,12 @@
+export interface FileSystemSyncAccessHandle {
+  read: (container: ArrayBuffer, opts: { at: number }) => number;
+  write: (data: ArrayBuffer | ArrayBufferView, opts?: { at: number }) => number;
+  flush: () => void;
+  close: () => void;
+  truncate: (newSize: number) => void;
+  getSize: () => number;
+}
+
 export function parsePath(path: string) {
   if (path === '/') return { parent: null, name: '' };
 
diff --git a/src/file.ts b/src/file.ts
index ebd39b3..be3878a 100644
--- a/src/file.ts
+++ b/src/file.ts
@@ -108,12 +108,7 @@ export class OPFSFileWrap {
 
       return (accPromise = new Promise(async (resolve, reject) => {
         try {
-          const fh = (await getFSHandle(this.#path, {
-            create: true,
-            isFile: true,
-          })) as FileSystemFileHandle;
-
-          const accHandle = await createOPFSAccess(this.#path, fh);
+          const accHandle = await createOPFSAccess(this.#path);
           resolve([
             accHandle,
             async () => {
diff --git a/src/opfs-worker.ts b/src/opfs-worker.ts
new file mode 100644
index 0000000..4bcaa10
--- /dev/null
+++ b/src/opfs-worker.ts
@@ -0,0 +1,63 @@
+import { FileSystemSyncAccessHandle, getFSHandle } from './common';
+
+const fileAccesserMap: Record<string, FileSystemSyncAccessHandle> = {};
+
+self.onmessage = async (e) => {
+  const { evtType, args } = e.data;
+
+  let accessHandle = fileAccesserMap[args.filePath];
+
+  try {
+    let returnVal;
+    const trans: Transferable[] = [];
+    if (evtType === 'register') {
+      const fh =
+        args.fileHandle ??
+        ((await getFSHandle(args.filePath, {
+          create: true,
+          isFile: true,
+        })) as FileSystemFileHandle);
+      accessHandle = await fh.createSyncAccessHandle();
+      fileAccesserMap[args.filePath] = accessHandle;
+    } else if (evtType === 'close') {
+      accessHandle.close();
+      delete fileAccesserMap[args.filePath];
+    } else if (evtType === 'truncate') {
+      accessHandle.truncate(args.newSize);
+    } else if (evtType === 'write') {
+      const { data, opts } = e.data.args;
+      returnVal = accessHandle.write(data, opts);
+    } else if (evtType === 'read') {
+      const { offset, size } = e.data.args;
+      const buf = new ArrayBuffer(size);
+      const readLen = accessHandle.read(buf, { at: offset });
+      returnVal =
+        readLen === size
+          ? buf
+          : // @ts-expect-error transfer support by chrome 114
+            buf.transfer?.(readLen) ?? buf.slice(0, readLen);
+      trans.push(returnVal);
+    } else if (evtType === 'getSize') {
+      returnVal = accessHandle.getSize();
+    } else if (evtType === 'flush') {
+      accessHandle.flush();
+    }
+
+    self.postMessage(
+      {
+        evtType: 'callback',
+        cbId: e.data.cbId,
+        returnVal,
+      },
+      // @ts-expect-error
+      trans
+    );
+  } catch (error) {
+    const err = error as Error;
+    self.postMessage({
+      evtType: 'throwError',
+      cbId: e.data.cbId,
+      errMsg: err.name + ': ' + err.message + '\n' + JSON.stringify(e.data),
+    });
+  }
+};