---
page_title: base64gzip function reference
description: The `base64gzip` function compresses the given string using gzip and then encodes the result in base64. 
---

# `base64gzip` Function

`base64gzip` compresses a string with gzip and then encodes the result in
Base64 encoding.

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

Strings in the Packer language are sequences of unicode characters rather
than bytes, so this function will first encode the characters from the string
as UTF-8, and then apply Base64 encoding to the result.

The Packer language applies Unicode normalization to all strings, and so
passing a string through `base64decode` and then `base64encode` may not yield
the original result exactly.

While we do not recommend manipulating large, raw binary data in the Packer
language, this function can be used to compress reasonably sized text strings
generated within the Packer language. For example, the result of this
function can be used to create a compressed object in Amazon S3 as part of
an S3 website.

## Related Functions

- [`base64decode`](/packer/docs/templates/hcl_templates/functions/encoding/base64decode) performs the opposite operation,
  decoding Base64 data and interpreting it as a UTF-8 string.
