● Encoding
Base64 Decoder
Decode Base64 encoded strings back into UTF-8 plain text.
Processed locally. Your input stays in this browser.
Zero Data Sent1 line•52 chars•52 B
Ctrl/Cmd+Enter run
Decoded Plain Text Output
1 line•36 chars•38 B
Read-only output
How It Works
- 1.Paste a Base64 encoded string into the input editor.
- 2.The decoder parses atob bytes and converts UTF-8 sequences safely using TextDecoder.
- 3.View or copy the decoded plain text.
Common Use Cases
- •Decoding Basic Auth headers (username:password).
- •Inspecting encoded payload data in HTTP requests or logs.
Frequently Asked Questions
What happens if the input is invalid?
The decoder will display a clear error message indicating invalid characters or malformed padding.