Instant Base64 Decoder with UTF-8 Support
Inspect JWT payloads, basic auth credentials, and email headers in milliseconds.
Key Highlights:
- Auto-padding detection
- URL-safe variant handling
- Clean syntax error alerts
Base64 Decoder
Runs in Your BrowserDecode standard and URL-Safe Base64 strings into readable text with automatic UTF-8 decoding and error handling for invalid characters.
Browser-based: this tool works on your device and does not send your input to an Alona Tool server. See the Privacy Policy for details.
Fast Processing
Loading Base64 Decoder… This tool is an interactive page and needs JavaScript enabled in your browser.
Example Usage & Test Cases
Encoded message
Input Scenario:
SGVsbG8gV29ybGQh
Generated Result:
Hello World!
How It Works
1
Reverses Base64 representation back into raw bytes and decodes through TextDecoder UTF-8.
Frequently Asked Questions
Our decoder automatically handles missing "=" padding and URL-safe characters (- and _).