Does this handle Unicode and emoji?

Yes. We use TextEncoder/TextDecoder so any UTF-8 string — including emoji and non-Latin scripts — round-trips correctly. The plain atob/btoa functions don't handle these natively, which is why this tool wraps them.

What is the difference between Base64 and Base64-URL?

Base64-URL replaces "+" with "-" and "/" with "_" so the output is safe to use in URLs without further encoding. Toggle the option below the input to switch between the two variants.

Is anything sent to a server?

No. Encoding and decoding run in your browser using the standard btoa/atob built-ins (with UTF-8 wrapping). Nothing is uploaded.

How do I decode a Base64 image?

Use the Image to Base64 tool instead — it shows a preview of the decoded image. This tool decodes to a UTF-8 string, which is correct for text but produces gibberish for binary content.

Why does my decoded output look wrong?

The most common causes are: extra whitespace or line breaks in the input (these are tolerated but worth checking), a Base64-URL string being decoded as standard Base64, or the input being binary rather than text.

Files never leave your device

Base64 Encoder / Decoder

Encode and decode Base64 strings. Handles UTF-8, including emoji and non-Latin scripts.

URL-safe (Base64-URL)

Plain text

Base64

How to use Base64 Encoder

Choose the Encode or Decode tab.
Paste your text into the input area.
The result appears instantly in the output box.
Use the copy button to grab the result.

Why Base64 exists

Base64 encodes binary data into 64 printable ASCII characters so it can travel through systems that only accept text — JSON payloads, email bodies, XML attributes, and URLs. The encoded representation is about 33% larger than the original, but it's the price of safe transport.

Common use cases

Embedding small images in CSS or HTML as data URIs
Encoding binary data inside JSON payloads
Storing API keys, secrets, and credentials in environment files
Creating Basic Auth headers (username:password Base64-encoded)
JWT segments (which use the URL-safe variant)