Base64 Decode

Use this Base64 decoder to convert Base64 strings back into readable text or original bytes. It helps inspect API payloads, logs, and encoded config values without leaving your browser.

1. Paste the Base64 string you want to decode.
2. Click "Decode" to convert it back.
3. Copy the output and use it in your app or workflow.

Base64 decoding reverses the 64-character mapping and returns the original bytes. It does not require a key; it simply undoes Base64 encoding.

Decoding and decrypting are different operations. Decoding is a reversible conversion with no secret. Decrypting reverses encryption and requires a key or passphrase to restore protected data.

For secure decryption needs, please visit our Decrypt Online page.

In Python, use the built-in base64 module:

import base64

encoded_str = "SGVsbG8sIFdvcmxkIQ=="
decoded_bytes = base64.b64decode(encoded_str)
decoded_str = decoded_bytes.decode("utf-8")
print(decoded_str)  # Outputs: Hello, World!

In JavaScript, use the atob() function for ASCII input:

const encoded = "SGVsbG8sIFdvcmxkIQ==";
const decoded = atob(encoded);
console.log(decoded);  // Outputs: Hello, World!

Decode Base64 values from the terminal:

# Decode a Base64 string
printf '%s' "SGVsbG8sIFdvcmxkIQ==" | base64 -d

# macOS uses: base64 -D

Paste any Base64 string, including encoded text, JSON, XML, or data URIs. If the output looks unreadable, the original content was binary or used a different character encoding.

Use Base64 decode online to inspect payloads, validate API output, or decode values embedded in logs and configuration files. Everything runs in the browser.

Examples include:

• Encoded: "SGVsbG8sIFdvcmxkIQ==" decodes to "Hello, World!"
• Encoded: "eyJuYW1lIjoiSm9obiJ9" decodes to '{"name":"John"}'