What's the difference between standard Base64 and URL-safe Base64?

URL-safe Base64 replaces +/ with -_ and omits padding (=) so it can be safely used in URLs or filenames. This tool uses standard Base64.

Are multi-byte characters encoded correctly?

Yes. Encoding and decoding are done on UTF-8 bytes, so non-ASCII text and emoji are handled correctly without corruption.

Is the content I enter sent to a server?

No. It's processed with the browser's built-in btoa/atob and TextEncoder/TextDecoder.

Is Base64 encryption?

No — it is a reversible encoding anyone can decode. Passwords or keys inside are fully exposed.

Can Korean text be encoded?

Yes — it is first converted to UTF-8 bytes, then Base64-encoded.

🔐 Base64 Encoder/Decoder

Encode text to Base64 or decode a Base64 string back to text.

Input

Result

How to use

Enter text or a Base64 string.
Click "Encode" or "Decode".
Use the copy button to grab the result.

🎯 Use Cases

Inspect or build an API Basic auth header value directly
Decode Base64 used in email attachments or data URIs
Check a Base64-encoded value stored in a config file

Example

Input

admin:s3cr3t!

Output

YWRtaW46czNjcjN0IQ==

Clicking "Encode" converts a user:password credential to Base64. The result can be used directly as an HTTP Basic auth header value: Authorization: Basic YWRtaW46czNjcjN0IQ==.

Base64 format at a glance

Base64 maps binary data onto 64 safe ASCII characters.

Element	Details
Character set	A-Z · a-z · 0-9 · + · / — 64 characters total
Padding `=`	Appended to reach a multiple of 4 when input is not a 3-byte multiple
Base64URL	URL-safe variant: + → -, / → _ — used in JWTs
Common uses	Data URIs, email attachments, JWT payloads, auth headers

FAQ

What's the difference between standard Base64 and URL-safe Base64?: URL-safe Base64 replaces +/ with -_ and omits padding (=) so it can be safely used in URLs or filenames. This tool uses standard Base64.
Are multi-byte characters encoded correctly?: Yes. Encoding and decoding are done on UTF-8 bytes, so non-ASCII text and emoji are handled correctly without corruption.
Is the content I enter sent to a server?: No. It's processed with the browser's built-in btoa/atob and TextEncoder/TextDecoder.
Is Base64 encryption?: No — it is a reversible encoding anyone can decode. Passwords or keys inside are fully exposed.
Can Korean text be encoded?: Yes — it is first converted to UTF-8 bytes, then Base64-encoded.