1. Home
  2. Base64 Tools
  3. Base64 Decode

Base64 Decode

Convert a Base64 string back to the original text, with full UTF-8 and Unicode support

Chars: {{ inputText.length }} Bytes: {{ byteCount }}
↓
{{ errorMsg }}
Go to Encode →

About Base64 Decoding

Base64 decoding reverses the process, turning a Base64-encoded string back into the original data. Base64 uses the 64 characters A-Z, a-z, 0-9, +, / and the = padding character. Decoding applies the opposite rule, converting every 4 Base64 characters back into 3 bytes.

In web development, decoding Base64 is common for JWT token headers and payloads, HTTP Basic Auth credentials, and inline data inside Data URIs.

This tool decodes Base64 strings containing UTF-8 / non-ASCII text and automatically handles spaces and line breaks in the input.

Examples

Input: SGVsbG8sIFdvcmxkIQ== → Output: Hello, World!

FAQ

Q: Why is the decoded text garbled?
A: Usually the original data was not UTF-8 encoded (e.g. GBK, ISO-8859-1). Confirm the original encoding, or use a decoder that lets you specify the encoding.
Q: Why does it say decoding failed?
A: Possible reasons: the input is not a valid Base64 string, contains illegal characters, or its length is incorrect (not a multiple of 4). Please check that the input is complete.
Q: Can it decode Base64URL format too?
A: This tool supports standard Base64 decoding. If the input is Base64URL (using - and _ instead of + and /), it will automatically convert and decode it.
Related Tools