---
layout: docs
page_title: base64decode - Functions - Configuration Language
description: The base64decode function decodes a string containing a base64 sequence.
---

# `base64decode` Function

`base64decode` takes a string containing a Base64 character sequence and
returns the original string.

Nomad uses the "standard" Base64 alphabet as defined in
[RFC 4648 section 4](https://tools.ietf.org/html/rfc4648#section-4).

Strings in the Nomad language are sequences of unicode characters rather
than bytes, so this function will also interpret the resulting bytes as
UTF-8. If the bytes after Base64 decoding are _not_ valid UTF-8, this function
produces an error.

## Examples

```shell-session
> base64decode("SGVsbG8gV29ybGQ=")
Hello World
```

## Related Functions

- [`base64encode`](/nomad/docs/reference/hcl2/functions/encoding/base64encode) performs the opposite operation,
  encoding the UTF-8 bytes for a string as Base64.