---
title: querystring.filtersep
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/functions/query-string/querystring-filtersep
---

```
STRING querystring.filtersep()
```

**Available in:** all subroutines

Returns the separator needed by the
`querystring.filter()` and
`querystring.filter_except()`
functions.

## Example

```vcl
set req.url = querystring.filter(req.url,
    "utm_source" + querystring.filtersep() +
    "utm_medium" + querystring.filtersep() +
    "utm_campaign");
```