Online Base64 Decoder
Online Base64 decoder: restore a Base64 string back to its original text in your browser instantly. Supports common encoding variants.
Tool input and output
Base64 decoding use cases
Base64 decoding restores an encoded string to its original text. It is commonly used to inspect encoded data from APIs, analyze HTTP request parameters, read encoded config values, and debug Base64 snippets found in logs.
This tool supports standard Base64 and the URL-safe variant. Strings with or without the trailing = padding decode correctly, and Unicode text such as Chinese is restored as UTF-8.
Which standard defines Base64?
Base64 turns binary data into text. It is an encoding, not encryption. The alphabet and padding rules are in RFC 4648.
“The encoding process represents 24-bit groups of input bits as output strings of 4 encoded characters.”
Frequently Asked Questions
Do I need to keep the trailing = when decoding?
No. The = is a valid padding character that this tool handles automatically. Variants without = are also supported and produce the same result.
The decoded output looks like garbled text. What now?
If the original content is not UTF-8 text (for example image or archive binary data), it cannot display correctly as text. This is expected and not a tool error.
Are encoding and decoding reversible?
Yes. Encoding a string and then decoding it restores the original content, and the reverse also holds. This is useful for verifying that data was transferred correctly.