ZeroServer.tools

Base64 to Decimal Converter

Decode a Base64 string into its raw bytes, shown as a decimal array.

Drop a .txt file containing Base64, or click to browseReads the file as text and decodes its contents as Base64.

Base64 input

Decimal byte array (13 bytes)

72 101 108 108 111 44 32 87 111 114 108 100 33

Separator

How Base64 to decimal conversion works

Base64 represents binary data using 64 printable characters, packing three raw bytes into four Base64 characters (6 bits each). To reverse it, this tool decodes the string back into its original bytes with the browser's built-in atob() function, then reads each byte's numeric value (0–255) to build a decimal array — for example, decoding SGk= (the text "Hi") yields the bytes 72, 105. Both standard Base64 and URL-safe Base64 (using - and _ instead of + and /) are accepted, along with missing padding. Everything runs locally in your browser — nothing is uploaded anywhere.