What is Base64 Decoding?
Base64 decoding is the reverse process of Base64 encoding. It converts Base64 encoded ASCII strings back into their original binary or text format. This is essential for reading data that has been encoded for safe transmission or storage.
When to Decode Base64
- Reading Email Attachments: Decode MIME encoded email attachments
- Processing Data URLs: Extract embedded images from data URIs
- API Responses: Decode Base64 encoded data from API responses
- JWT Tokens: Decode JWT payload to read claims
- Configuration Data: Read encoded configuration values
- Debugging: Inspect Base64 encoded data during development
Security Considerations
⚠️ Important Security Notes
- Base64 is NOT encryption - decoded data is readable by anyone
- Never use Base64 alone to protect sensitive information
- Always validate and sanitize decoded data before use
- Be cautious of malicious encoded payloads
- Use proper encryption (AES, RSA) for security needs
Common Errors
- Invalid characters: Base64 only uses A-Z, a-z, 0-9, +, /, and =
- Incorrect padding: Base64 strings should end with 0-2 '=' characters
- Corrupted data: Even one wrong character can cause decoding to fail
- Wrong encoding: Ensure the data was actually Base64 encoded
Example
Base64 Input: SGVsbG8sIFdvcmxkIQ==
Decoded Output: Hello, World!