Base64 Decoder
Decode a Base64-encoded string back into readable UTF-8 text and inspect its content.
Decoded text
Your result will appear here.
What is Base64 Decoder?
Base64 Decoder parses RFC 4648 Base64 strings and reconstructs the original plain text or UTF-8 content. Using browser TextDecoder APIs, it restores international text, diacritics, and emojis without character corruption. Useful for inspecting authorization tokens, API responses, and encoded payloads locally without transmitting data.
How to use Base64 Decoder
- 1Paste a Base64-encoded string into the input editor.
- 2The decoder automatically parses the byte sequence and renders the decoded text.
- 3Click Copy to copy the decoded plain text output.
Key features
Accurate UTF-8 Reconstruction
Decodes byte arrays with TextDecoder to restore international text, diacritics, and emojis without garbled characters.
Malformed Input Detection
Catches invalid characters, corrupted padding, and incomplete byte sequences with clear alerts.
Whitespace & Padding Tolerance
Automatically trims surrounding whitespace and line breaks from pasted input strings.
100% Private In-Browser Decoding
Sensitive tokens, authorization headers, and decoded secrets never leave your device.
Examples & use cases
Basic Auth Credentials
Decoding username and password from a basic authorization header
YWRtaW46c2VjcmV0MTIz
admin:secret123
Unicode & Emoji Payload
Restoring multi-byte international text and emojis
SGVsbG8sIOS4lueVjCEg8J+agA==
Hello, 世界! 🚀
Frequently asked questions
Helpful guides & tutorials
Related tools
Encode text into Base64.
Decode percent-encoded URL strings and query parameters to plain text.
Decode a JSON Web Token header and payload.
Decode data: URIs or encode files (up to 5MB) into Base64 data URIs.
Percent-encode text and parameters for safe use in URLs and APIs.