How to decode a Base64 string online

Base64 is a way of representing binary data or text as ASCII characters — you will run into it in JSON payloads, JWTs, data URIs, email attachments and API responses. Decoding turns that scrambled-looking string back into readable text. The decoder below runs entirely in your browser, so even sensitive tokens never leave your device.

Open the Base64 Encode/Decode

Step by step

  1. 1

    Open the Base64 tool

    Open the Base64 Encoder / Decoder. There is nothing to install and no sign-up.

  2. 2

    Paste your Base64 string

    Paste the encoded string into the input box and switch the mode to “Decode”.

  3. 3

    Read the decoded text

    The decoded plain text appears instantly as you type. Standard and URL-safe Base64 are both handled.

  4. 4

    Copy the result

    Click copy to grab the decoded output. To go the other way, switch to “Encode” and paste plain text.

Tips

  • If decoding produces gibberish, the string may be URL-safe Base64 (using - and _ instead of + and /) or may be missing its = padding — the tool tolerates both.
  • A Base64 string that decodes to more Base64 is common in JWTs: decode each dot-separated segment separately, or use the dedicated JWT decoder.
  • Base64 is encoding, not encryption — never treat a Base64 string as a secure secret.

Frequently asked questions

Is it safe to decode a Base64 token here?
Yes. Decoding happens entirely in your browser with JavaScript — the string is never sent to any server, so even access tokens stay private.
What is the difference between Base64 and encryption?
None in terms of security. Base64 is a reversible encoding anyone can decode. It is used to make binary data safe to transport as text, not to protect it.
Why does my decoded text have strange characters?
The original data was probably binary (an image, gzip, or a protobuf) rather than UTF-8 text. Base64 only reveals readable text when the underlying bytes were text.

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