What is Base64 encoding?

Base64 is a way of representing binary data using only 64 printable ASCII characters (A–Z, a–z, 0–9, + and /). It lets you safely transmit or store data — like images, files, or text with special characters — in systems that only reliably handle plain text, such as URLs, JSON, XML, or email.

How do I encode text to Base64?

Paste or type your text into the input box on the left with "Encode" selected. The Base64 result appears instantly on the right thanks to live mode. Click "Copy" to copy it to your clipboard.

How do I decode a Base64 string?

Switch to "Decode", paste your Base64 string into the input box, and the original text appears on the right. If the string is not valid Base64, you will see a clear error message.

Is this Base64 tool safe and private?

Yes. All encoding and decoding happens entirely in your browser using JavaScript — your data is never uploaded to a server. This makes it safe to use even with sensitive text.

What is URL-safe Base64?

URL-safe Base64 replaces the "+" and "/" characters with "-" and "_" so the result can be used in URLs and filenames without additional escaping. Enable the "URL-safe variant" option before encoding.

Does Base64 encryption keep my data secure?

No. Base64 is an encoding, not encryption — anyone can decode it. Use it for safe transport and storage of data, not to protect secrets. For confidentiality you need real encryption.

URL-Safe Base64 Explained — Differences & When to Use It

Standard Base64 uses the characters +, /, and =. Those are unsafe in URLs and filenames, so a URL-safe variant swaps them out. It is defined in RFC 4648.

Standard vs URL-safe Base64

+ becomes - (minus)
/ becomes _ (underscore)
= padding is often dropped entirely

Everything else (A–Z, a–z, 0–9) stays the same, so the two only differ by those characters.

Why + / = break URLs

In a URL query string a + is interpreted as a space, / is a path separator, and = separates keys from values. Left as-is, standard Base64 gets mangled or must be percent-encoded — which is exactly what URL-safe Base64 avoids.

Convert it online

Open the Base64 tool, enable the URL-safe variant option, then encode — the output uses - and _ instead of + and /.

URL-safe Base64 in code

// JavaScript — encode URL-safe
const urlSafe = btoa(str)
  .replaceAll("+", "-")
  .replaceAll("/", "_")
  .replaceAll("=", "");

// JavaScript — decode URL-safe
const std = urlSafe.replaceAll("-", "+").replaceAll("_", "/");
const original = atob(std);

# Python
import base64
enc = base64.urlsafe_b64encode(b"data").decode()
dec = base64.urlsafe_b64decode(enc)

Where URL-safe Base64 is used

JWTs — each part of a token is URL-safe Base64 without padding.
URL query parameters and path segments.
Filenames and cache keys, where / is illegal.

Note: URL-safe Base64 is different from URL percent-encoding — Base64 re-encodes the data, while URL encoding only escapes reserved characters. Try the Base64 tool with the URL-safe option to see it.