Base64
Linux Terminal Util
base64
Base64 encode/decode data and print to standard output.
Syntax
Key
-
-d
--decode
Decode data. -
-i
--ignore-garbage
When decoding, ignore non-alphabet characters. -
-w
--wrap=COLS
Wrap encoded lines after COLS characters (default 76). Use 0 to disable line wrapping. -
--help
Display this help and exit. -
--version
Output version information and exit.
With no FILE, or when FILE is -, read from standard input.
Mandatory arguments to long options are mandatory for short options too.
Overview
Base64 is designed to carry data stored in binary formats across channels that only reliably support text. Base64 is particularly prevalent on the internet where its uses include the ability to embed image files or other binary assets inside textual assets such as HTML and CSS files.
For instance, background images and fonts can be specified in a CSS stylesheet file as data: URIs, instead of separate files.
A favicon:
The base64 encoded data is about 33% larger than the raw data.
The data are encoded as described for the base64 alphabet in RFC 4648.
This uses an alphabet of A-Z, a-z, 0-9, +/=
Padding at the end of the data is performed using the = character.
When decoding, the input may contain newlines in addition to the bytes of the formal base64 alphabet. Use --ignore-garbage to attempt to recover from any other non-alphabet bytes in the encoded stream.
base64 is often used to encode .PNG and .JPG data for use in HTML / CSS however data URIs can accept .SVG directly, encoding SVG in base64 will just make the file larger.
base64 is part of the coreutils (basic file, shell and text manipulation utilities) project.
Examples
- Encode the text file sample.txt:
- Encode a binary photo file:
- Decode the file encoded.txt:
- Encode a string: