---
name: "fastbase64"
section: "1"
platform: "linux"
package: "simdutf"
version: "9.2.2-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/fastbase64"
---

# fastbase64(1)

base64 encode/decode data and print to standard output

## NAME

fastbase64 - base64 encode/decode data and print to standard output

## SYNOPSIS

**fastbase64** \[**-Ddh**\] \[**-b** *num*\] \[**-i** *in\_file*\] \[**-o** *out\_file*\]

## DESCRIPTION

**fastbase64** encodes or decodes base64 data using the high-performance simdutf library. By default, it encodes binary input to base64 output. On large files, it can be several times faster than standard base64 tools. If a second filename is provided, it is used as the output file. Otherwise, output goes to standard output.

## OPTIONS

- **-b, --break *num***

  break encoded output up into lines of length *num* (default 0, meaning no breaks)

- **-D, -d, --decode**

  decode input

- **-h, --help**

  display this message

- **-i, --input *in\_file***

  input file (default: "-" for stdin)

- **-o, --output *out\_file***

  output file (default: "-" for stdout)

- **-w, --wrap=*NUM***

  same as **-b**

- **-e, --encode**

  encode input (default)

- **--ignore-garbage**

  when decoding, ignore non-alphabet characters

- **--version**

  output version information and exit

## EXAMPLES

- Encode a file (default, no wrapping):

  **fastbase64 -i myfile.txt**

- Decode base64 data:

  **fastbase64 -d -i encoded.txt**

- Encode with custom line wrapping:

  **fastbase64 -b 76 -i myfile.txt**

## SEE ALSO

[**base64**(1)](/base64/1.md), [**fastbase64.coreutils**(1)](/fastbase64.coreutils/1.md), [**iconv**(1)](/iconv/1.md)

## AUTHOR

Written by the simdutf development team.