Base64 Decode Online

Use our free online Base64 Decode tool to decode any Base64 text.


What is Base64 Decoding

Base64 decoding is the process of converting a Base64 encoded string back into its original binary representation. It is the reverse operation of Base64 encoding and is commonly used to retrieve binary data, such as images or files, that have been encoded using Base64.

The process of Base64 decoding involves the following steps:

  1. Take the Base64 encoded string as input.
  2. Remove any whitespace or line breaks from the encoded string, as they are not part of the actual Base64 data.
  3. Map each character of the encoded string back to its corresponding 6-bit value based on the Base64 encoding table.
  4. Combine the 6-bit values into a stream of bytes, resulting in the original binary data.
  5. If the original data was padded with '=' characters (to make it a multiple of 3 bytes during encoding), remove them from the end of the decoded data.

Here is an example of Base64 decoding for the encoded string "SGVsbG8sIFdvcmxkIQ==":

SGVsbG8sIFdvcmxkIQ== -> Hello, World!

The Base64 encoded string "SGVsbG8sIFdvcmxkIQ==" is decoded back into the original binary data "Hello, World!". Decoding the Base64 string allows us to retrieve the original information that was encoded.

Base64 decoding is widely used in various scenarios, such as decoding images embedded in HTML or decoding data received from APIs that use Base64 encoding for transmitting binary data.

It is important to note that Base64 decoding should only be performed on data that you trust, as it can reveal the original content to anyone who has access to the encoded string. Additionally, improper or corrupted Base64 encoded strings may result in errors during decoding, so it's essential to ensure that the encoded data is valid before attempting to decode it.

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