Base64 Encode and Decode using OpenSSL

Base64 is an encoding and decoding scheme commonly used to convert binary data into a printable ASCII text format and back. This tutorial demonstrates how to perform Base64 encoding and decoding using OpenSSL.

Commands have been tested on Ubuntu.

Encoding string

The openssl base64 command allows you to perform Base64 encoding and decoding. You can encode a string as shown below:

echo "Hello world" | openssl base64

Decoding string

To decode Base64, use the -d option:

echo "SGVsbG8gd29ybGQK" | openssl base64 -d

Encoding file

Create a text file for testing:

echo "Hello world" > data.txt

Encode the content of a text file and display the result in the terminal:

openssl base64 -in data.txt

Encode the content of a text file and save the result to a different file:

openssl base64 -in data.txt -out out.txt

Decoding file

Create a text file containing Base64 encoded data:

echo "SGVsbG8gd29ybGQK" > encoded_data.txt

Decode the content of a text file and display the result in the terminal:

openssl base64 -d -in encoded_data.txt

Decode the content of a text file and save the result to a different file:

openssl base64 -d -in encoded_data.txt -out out.txt