Tools
B64

Base64 Decoder

Output
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Base64 Decoder — Decode Base64 Online Free

What is Base64 Decoder?

Decode Base64 strings to plain text. Reverse Base64 encoding instantly.

Base64 Decoder converts Base64 strings back to their original form. Paste a Base64-encoded string and get the decoded output. Handles UTF-8 text and binary data. Useful for debugging JWT tokens, data URIs, and API responses. All decoding happens in your browser.

How to Use Base64 Decoder

  1. Paste or type your input into the editor on the left panel.
  2. Results update automatically while you type. You can also press Ctrl+Enter to force a refresh.
  3. View the result in the output panel on the right with full syntax highlighting.
  4. Use Copy or Download to export the result.
  5. Drag and drop .json or .txt files directly into the editor.

Example

Input:

SGVsbG8sIFdvcmxkIQ==

Output:

Hello, World!

Common Use Cases

  • Decode data URIs
  • Read JWT payloads
  • Extract embedded data

Base64 vs Decoded

Input
Base64 string
Plain text
Output
Original data
N/A
Use
Reverse encoding
N/A

Common Errors

  • Invalid characters
  • Missing padding
  • Wrong encoding

Why Use Our Base64 Decoder?

  • 100% client-side — your data never leaves your browser. No server processing, no data collection.
  • No sign-up required — start using the tool instantly with no registration or installation.
  • Keyboard shortcuts — press Ctrl+Enter to run, ? for shortcuts list, Ctrl+B to toggle sidebar.
  • Persistent state — your input is automatically saved across sessions using local storage.
  • IDE-style interface — Monaco Editor (the engine behind VS Code) with syntax highlighting and error detection.
  • Multi-format conversion — convert between JSON, XML, CSV, and YAML without switching tools.

Frequently Asked Questions

What is Base64 decoding?

Base64 decoding reverses the encoding process, converting Base64 strings back to original data.

Why does decoding fail?

Invalid characters, incorrect padding, or corrupted input cause failures.

Can it decode images?

It decodes to binary/text. For images, you would need to handle the binary output.

Is it secure?

Decoding runs in your browser. Your data is not sent anywhere.

Is it free?

Yes. Free, no sign-up, 100% client-side.

Try Base64 Decoder Now

Paste your data into the editor above for instant processing. Use Ctrl+Enter anytime to re-run quickly.

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