How do I decode Base64 text?

Paste your Base64-encoded string into the input field and click submit. The tool instantly decodes it back to the original text.

Can Base64 decode binary files?

This tool decodes Base64 to text. For decoding Base64 to images, use our Base64 to Image converter tool.

Why does my Base64 string have padding (=)?

Base64 uses = signs as padding to ensure the encoded output length is a multiple of 4. One or two = characters may appear at the end.

Base64 Decoder

What Is Base64 Decoding?

Base64 decoding is the reverse of Base64 encoding: it converts a Base64-encoded string back into its original binary or text representation. When you receive a Base64 string in an API response, HTTP header, database field, or email attachment, you need a decoder to recover the original data. Base64-encoded strings are easily recognizable — they consist entirely of letters, digits, +, /, and trailing = padding characters, and they are always approximately 33% longer than the original data. Decoding is a lossless operation: the output is byte-for-byte identical to the original input before encoding. This tool decodes both standard Base64 (RFC 4648) and URL-safe Base64 (which uses - and _ instead of + and /), covering the full range of real-world use cases you'll encounter in web and API development.

How to Use the Base64 Decoder

Paste the Base64-encoded string into the input field. Make sure to include any trailing = padding characters.
Click "Decode" to convert the Base64 string back into its original text or data representation.
Review or copy the decoded output — if the original data was plain text you'll see it immediately; if it was binary data you can inspect the raw bytes.

The decoder handles whitespace and line breaks gracefully, so you can paste multi-line Base64 strings (common in PEM certificates) without pre-processing.

Common Use Cases

Decoding JWT tokens: Base64-decode the header and payload sections of a JSON Web Token to inspect its claims.
Reading API responses: Decode Base64-encoded fields in API responses that contain file content, images, or binary data.
Inspecting email headers: Decode Base64-encoded email subjects, bodies, and attachments in raw email source.
Debugging HTTP Basic Auth: Decode the value after "Basic " in an Authorization header to see the username and password.
PEM certificates: Decode Base64 blocks in .pem files to inspect certificate data and key material.
Security research: Decode obfuscated Base64 payloads found in malware samples, phishing scripts, or suspicious code.