FileSystemSyncAccessHandle: truncate() method
 
 
 
 Baseline
 
 Widely available
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2023.
Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is only available in Dedicated Web Workers.
The truncate() method of the
FileSystemSyncAccessHandle interface resizes the file associated with the handle to a specified number of bytes.
Syntax
truncate(newSize)
Parameters
newSize- 
The number of bytes to resize the file to.
 
Return value
None (undefined).
Exceptions
InvalidStateErrorDOMException- 
Thrown if the associated access handle is already closed, or if the modification of the file's binary data otherwise fails.
 QuotaExceededError- 
Thrown if the
newSizeis larger than the original size of the file, and exceeds the browser's storage quota. TypeError- 
Thrown if the underlying file system does not support setting the file size to the new size.
 
Examples
async function truncateFile() {
 // Get handle to draft file
 const root = await navigator.storage.getDirectory();
 const draftHandle = await root.getFileHandle("draft.txt", { create: true });
 // Get sync access handle
 const accessHandle = await draftHandle.createSyncAccessHandle();
 // Truncate the file to 0 bytes
 accessHandle.truncate(0);
 // Persist changes to disk.
 accessHandle.flush();
 // Always close FileSystemSyncAccessHandle if done.
 accessHandle.close();
}
Specifications
| Specification | 
|---|
| File System> # api-filesystemsyncaccesshandle-truncate>  | 
 
Browser compatibility
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