Base64 Encoder / Decoder

Encode text or files into Base64 format and decode Base64 strings back to their original form securely in-browser.

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Detailed Guide: Understanding Base64 Binary Encoding

Base64 is a binary-to-text encoding method that translates arbitrary data (including binaries, archives, and images) into a string sequence of 64 printable ASCII characters: A-Z, a-z, 0-9, +, and /, with = representing padding bytes.

How Base64 Works:

The encoder takes 3 bytes of binary data (24 bits) and breaks them into 4 groups of 6 bits each. Each 6-bit value maps to one of the 64 characters in the index list. Because 3 bytes are encoded into 4 characters, Base64 increases data file sizes by approximately 33%.

Applications in Web Development:

  • Inline Data URIs: Speed up load times for small icons by embedding them directly: <img src="data:image/png;base64,iVBORw..." />.
  • API Integration: Send structured JSON requests containing files or keys without causing encoding breaks from special control characters.

How to Use Base64 Encoder / Decoder

1

Choose Action

Select between 'Encode Text', 'Decode Text', or 'File to Base64' based on your requirements.

2

Input Contents

Type plain text, paste a base64 string, or drag and drop a file up to 5MB.

3

Copy Output

Review the validated, converted Base64 output and copy it securely.

Frequently Asked Questions

What is Base64 encoding used for?

Base64 encoding schemes are used to represent binary data in an ASCII string format. It is widely used to embed images directly in HTML/CSS (via data URIs), send file attachments in emails, and transmit binary payloads over APIs.

Are my files or text sent to a server?

No. Everything runs strictly in your web browser using HTML5 FileReader and JavaScript text decoders. Your data remains fully private and never leaves your computer.

What is the maximum file size for conversions?

We set a local check to restrict file inputs to 5MB. This ensures processing remains lightning fast without freezing your browser memory.