JSON Utility
Free online tool

Base64 Decoder Online

Decode valid Base64 data back into UTF-8 text and receive a clear error when the supplied value is malformed.

Decoded text

How to use the Base64 Decoder

  1. Enter or paste your input in the tool above.
  2. Choose the available options and select Run tool or Process locally.
  3. Review, copy, or download the generated result.

What does the Base64 Decoder do?

The decoder converts Base64 characters into bytes and then interprets those bytes as UTF-8. It is suited to textual payloads; arbitrary binary data may not display meaningfully as text.

Common uses

  • Read encoded API or configuration values
  • Check a Base64 test vector
  • Recover UTF-8 text from a transport-safe representation

Base64 Decoder example

Example input

SGVsbG8sIHdvcmxkIQ==

Example output

Hello, world!

Limitations and important notes

  • Binary files should be handled as files rather than text
  • Base64URL may require URL-safe normalization
  • Decoding does not make untrusted content safe

Private browser-based processing

Your data is processed locally in your browser and is not uploaded or stored on our servers. Tool inputs are not saved to local storage.

Base64 Decoder features

  • Free to use with no registration
  • Fast client-side processing
  • Clear validation and useful error messages
  • Copy and download support
  • Mobile-friendly accessible interface

Frequently asked questions

Why does Base64 decoding fail?

The input may contain invalid characters, incorrect padding, a truncated value, or a Base64URL alphabet.

Why is decoded output unreadable?

The source may represent binary data or text in an encoding other than UTF-8.

Is the Base64 Decoder free to use?

Yes. The Base64 Decoder is completely free and requires no account or installation.

Is my data uploaded when using Base64 Decoder?

No. Your input and result are processed locally inside your browser and are not sent to our server.

Can I use Base64 Decoder on mobile?

Yes. The tool works in modern desktop and mobile browsers.

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