Definition

Base64 is a binary-to-text encoding scheme that represents binary data using 64 ASCII characters: A–Z, a–z, 0–9, +, / and = as padding. It maps groups of 6 bits to one of 64 printable characters so binary can be safely transported over text-only channels.

Why Base64 Exists

• Text-only channels: Some protocols or formats (JSON, XML, email bodies) are text-based and cannot carry raw binary reliably.
• Legacy systems: Older systems and transport layers may corrupt raw bytes. Base64 prevents that.
• Embedding: Easily embed images, small files, or certificates directly into HTML/CSS or JSON.

How to Encode & Decode

Use the EasyBase64 Encoder or EasyBase64 Decoder for instant client-side conversions. You can also use built-in tools on your machine:

JavaScript (Browser)

Encode UTF-8 text:

// encode
      const encoded = btoa(unescape(encodeURIComponent("Hello")));
      console.log(encoded); // SGVsbG8=

      // decode
      const decoded = decodeURIComponent(escape(atob(encoded)));
      console.log(decoded); // Hello

Node.js (Buffer)

// encode
    const base64 = Buffer.from("Hello", "utf8").toString("base64");
    // decode
    const text = Buffer.from(base64, "base64").toString("utf8");

Linux / macOS (CLI)

# encode
    echo -n "Hello" | base64
    # decode
    echo "SGVsbG8=" | base64 --decode

URL-safe Base64

URL-safe variant replaces + with -, / with _, and may remove padding =. Useful for putting Base64 in URLs or filenames.

Limitations & Best Practices

• Size increase: Base64 expands data by ~33% — avoid embedding large files directly in HTML or CSS.
• Not secure: Don’t use Base64 to hide secrets — use encryption for confidentiality.
• MIME & padding: Some decoders are strict about padding. If you strip padding for URL safety, make sure the decoder handles it.
• Performance: For heavy conversions, client-side is fine, but server-side batch conversions may be more appropriate.