Base64 to Binary Converter
Decode Base64 into its original binary bytes. Paste standard Base64 or Base64URL data and inspect the resulting 8-bit binary values, decimal bytes, hexadecimal bytes, decoded byte count, padding and validation details.
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Base64 to Binary Converter
The Base64 to Binary Converter decodes Base64 text into the original binary byte sequence. Each decoded byte is displayed as an 8-bit binary value, making it easy to inspect the actual data represented by a Base64 string.
The tool supports both standard Base64 and the URL-safe Base64URL variation. It also displays decimal and hexadecimal forms of every decoded byte so the same data can be examined in multiple number systems.
How to Convert Base64 to Binary
Paste a Base64 string into the input field and choose Auto Detect, Standard Base64 or Base64URL. Then choose how you want the binary bytes separated and click Convert Base64 to Binary.
Base64:
SGVsbG8=
Decoded bytes:
48 65 6C 6C 6F
Binary:
01001000 01100101 01101100 01101100 01101111How Base64 Decoding Works
Base64 represents binary data using characters selected from a 64-character alphabet. Because 64 values require six bits, every Base64 data character maps to a six-bit number.
Base64 characters
↓
6-bit indexes
↓
Combined bit stream
↓
8-bit decoded bytes
↓
Original binary dataPadding characters at the end of standard Base64 indicate that the final encoded block represents fewer than three original bytes.
Example: SGVsbG8= to Binary
The Base64 value SGVsbG8= represents the five-byte sequence commonly displayed as the ASCII text Hello.
Base64:
SGVsbG8=
Hex:
48 65 6C 6C 6F
Decimal:
72 101 108 108 111
Binary:
01001000
01100101
01101100
01101100
01101111Base64 Character Groups
Four Base64 characters normally represent three decoded bytes. The relationship comes from the fact that four 6-bit values contain 24 bits and three bytes also contain 24 bits.
4 × 6 bits
= 24 bits
3 × 8 bits
= 24 bitsBase64 Padding
Standard Base64 uses equals signs at the end when the final input group did not contain a complete three bytes before encoding.
| Base64 | Decoded Bytes | Padding |
|---|---|---|
| TQ== | 1 | 2 × = |
| TWE= | 2 | 1 × = |
| TWFu | 3 | None |
Standard Base64 vs Base64URL
Base64URL modifies two characters from the standard Base64 alphabet so encoded data can be placed more safely in URLs and filename-oriented contexts.
| Index | Standard | Base64URL |
|---|---|---|
| 62 | + | – |
| 63 | / | _ |
Base64URL commonly omits trailing equals-sign padding. Auto Detect recognizes hyphen or underscore characters and normalizes the value before decoding.
Binary Output With or Without Spaces
Each decoded byte contains eight bits. By default the converter separates those bytes with spaces so boundaries remain visible. You can instead output one continuous binary string, comma-separated bytes or one byte per line.
With spaces:
01000001 01000010 01000011
Without spaces:
010000010100001001000011Base64 Is Not Encryption
Base64 is only a reversible binary-to-text encoding. It does not hide or secure the underlying information. Anyone who receives a Base64 value can decode it back to the original bytes.
Sensitive information should therefore not be considered protected simply because it appears as Base64 text.
Why Decode Base64 to Binary?
Binary output is useful when you need to inspect individual bits, compare encoded data against a protocol specification, understand bit fields, debug byte-level payloads or study how Base64 reconstructs its original data.
The accompanying hexadecimal and decimal output can also make it easier to compare the result against hex dumps, packet captures, memory values and technical documentation.