base64

Additional Notes

base64 converts binary or text data to and from Base64. Base64 is commonly used when binary data must travel through text-only formats such as JSON, email, environment variables, or simple copy-paste workflows.

It is encoding, not encryption. Anyone can decode Base64.

Syntax

base64 [options] [file]
base64 -d [file]

Parameters

• file: Input file. If omitted, standard input is used.
• options: Decode, wrapping, and ignore-garbage controls.

Common Options

• -d, --decode: Decode Base64 input.
• -w COLS, --wrap=COLS: Wrap encoded lines after COLS characters. Use -w 0 for no wrapping on GNU systems.
• -i, --ignore-garbage: Ignore non-alphabet characters while decoding.

Examples

echo -n "hello" | base64

Encode text without a trailing newline.

echo "aGVsbG8=" | base64 -d

Decode Base64 text.

base64 image.png > image.b64

Encode a binary file into text.

base64 -d image.b64 > image.png

Decode back to the original binary file.

Practical Notes

• Use echo -n when the newline should not be part of encoded data.
• Base64 increases size by roughly one third.
• Do not treat Base64 as secret protection.