---
title: std.toupper
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/functions/strings/std-toupper
---

```
STRING std.toupper(STRING s)
```

**Available in:** all subroutines

Changes the case of a string to uppercase. For example, `std.toupper("hello");` 
will return `"HELLO"`.

## Example

```vcl
set beresp.http.x-scream = std.toupper("yes!");
```