Decode Base64-encoded strings back to plain text or binary. Detects and handles both standard and URL-safe Base64 variants. Instant, private, browser-based decoding.
Key Features
Auto-detects standard Base64, URL-safe Base64, and missing padding
Decodes multi-byte UTF-8 text, Unicode symbols, and emoji accurately
Highlights invalid Base64 characters and padding issues
Processed over HTTPS in memory; do not paste live passwords or private keys
How to Use
Paste your Base64 encoded string into the input area.
Click "Decode Base64" to reveal the original text.
Inspect the decoded plain-text output.
Copy the decoded text directly to your clipboard.
Example
Sample input
SGVsbG8sIFdvcmxkIQ==
Sample output
Hello, World!
Edge Cases
URL-safe Base64 (- and _ alphabet)
Missing padding characters
Invalid character in alphabet
Frequently Asked Questions
Why does my Base64 string fail to decode?
Common decoding failures occur due to non-Base64 characters (such as stray spaces or line breaks), incorrect string length, or corrupted trailing padding ("=").
Can this tool decode JWT tokens?
Yes. JWT tokens consist of Base64URL-encoded header, payload, and signature segments. You can paste individual payload parts to inspect their JSON contents.
Are my decoded strings sent to a server?
Decoding runs on our server over HTTPS. Input is processed in memory and is not stored or logged.
Privacy notice: when you run this tool, your input is sent over HTTPS to our server, processed in memory and returned. It is not stored or logged. Avoid pasting live secrets such as private keys or passwords.