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Base64 Encoder / Decoder

Encode text or files to Base64, or decode Base64 back to text — UTF-8 safe, with URL-safe variant and live byte counter. 100% private.

100% private

This tool runs entirely in your browser. Your input never leaves your device — no uploads, no tracking, no accounts.

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About Base64 Encoder / Decoder

Encode text or files to Base64, or decode Base64 back to text — UTF-8 safe, with URL-safe variant and live byte counter. 100% private.

How to use

  1. Enter your input in the tool above.
  2. Adjust any options (indent, format, etc.) to your preference.
  3. Use the Copy or Download buttons to save the result.
  4. Everything happens locally — your data never leaves your browser.

Frequently asked questions

Why does this tool handle UTF-8 correctly when many don't?
JavaScript's built-in btoa() only accepts Latin1 characters. This tool uses TextEncoder/TextDecoder to convert UTF-8 bytes to Base64, so emoji, CJK, and other non-ASCII characters encode and decode correctly.
What is the URL-safe variant?
Standard Base64 uses '+' and '/' which break in URLs. The URL-safe variant (RFC 4648 §5) replaces them with '-' and '_', and optionally drops the trailing '=' padding. Useful for JWTs, data URLs, and query parameters.