---
title: resourceBytes
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/url/resourcebytes
---

# resourceBytes

The URL’s resource data, as an asynchronous sequence of bytes.

## Declaration

```swift
var resourceBytes: URL.AsyncBytes { get }
```

## Discussion

Discussion Use this property with Swift’s for-await-in syntax, to read the contents of a URL byte-by-byte, like this: guard let url = URL(string: "https://www.example.com") else {     return } do {     // Read each byte of the data as it becomes available.     for try await byte in url.resourceBytes     {         // Do something with byte.     } } catch {     print ("Error: \(error)") } To wait for the entire resource to load, use the URLSession method data(from:delegate:) with the await keyword. URLSession also offers methods to upload data to a URL endpoint and download a URL’s contents to a file.

## See Also

### Loading URL contents asynchronously

- [lines](foundation/url/lines.md)
- [URL.AsyncBytes](foundation/url/asyncbytes.md)