Base64 Encoder & Decoder

Convert plain text to Base64 encoding or decode Base64 strings back to readable text. All processing happens locally in your browser for complete privacy.

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Base64 Encoder & Decoder

Paste your text or Base64 string below, then click Encode or Decode. Results appear instantly.

Input Text or Base64

Enter plain text to encode or Base64 string to decode.

Result

Understanding Base64 Encoding

Learn when and why to use Base64 for data transmission and storage.

What is Base64?

Base64 is an encoding scheme that converts binary data into ASCII text. It's commonly used to embed images in HTML/CSS, transmit data over text-only protocols, and encode credentials in HTTP headers. The encoding increases data size by roughly 33%, but ensures safe transmission through systems that only handle text.

Common Use Cases

  • Email Attachments: MIME uses Base64 to encode binary files for email transmission.
  • Data URIs: Embed images directly in CSS or HTML without external file requests.
  • API Tokens: Many authentication systems encode credentials or tokens in Base64.
  • JSON Payloads: Include binary data within JSON by Base64-encoding it first.

Important Notes

Base64 is an encoding method, not encryption. It provides no security—anyone can decode Base64 strings. Never use Base64 alone to protect sensitive data; combine it with proper encryption when security is required.

Frequently Asked Questions

Common questions about Base64 encoding and decoding.

Is Base64 encoding secure?

No, Base64 is not encryption. It's simply an encoding format that converts data to text. Anyone can easily decode Base64 strings. For security, use proper encryption methods like AES or RSA.

Does my data leave my browser?

No. All encoding and decoding happens locally in your browser using JavaScript. Your data never leaves your device and is not sent to any server.

Why does Base64 make data larger?

Base64 encodes 3 bytes of binary data into 4 ASCII characters, resulting in approximately 33% size increase. This trade-off ensures the data can be safely transmitted through text-only systems.

Can I encode files like images?

This tool is designed for text input. To encode binary files like images, you would need a file upload feature that reads the file as binary data first. Many image-to-Base64 converters are available online for this purpose.