Base64 Encoder & Decoder

edit_note Input

text_fields 0 Input Chars

straighten 0 B Input Bytes

text_fields 0 Output Chars

straighten 0 B Output Bytes

code Output

Encoded Base64 will appear here...

How to Use

1

Enter your text
Type or paste the text you want to encode, or a Base64 string you want to decode.
2

Choose mode
Select Encode to convert text to Base64, or Decode to convert Base64 back to text.
3

Get instant results
The output updates in real time as you type. Unicode text is fully supported.
4

Copy the result
Click Copy Output to grab the encoded or decoded text for use in your project.

Common Use Cases

image

Data URIs

Embed small images, fonts, or files directly in HTML and CSS using Base64-encoded data URIs.

key

Basic Authentication

Encode username:password pairs for HTTP Basic Auth headers used in API requests.

swap_horiz

Binary Data in JSON

Safely transmit binary data through JSON APIs by encoding it as a Base64 string.

token

JWT & Tokens

Decode JWT tokens and API keys to inspect their payload without external tools.

Frequently Asked Questions

What is Base64 encoding?

Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It uses 64 characters (A-Z, a-z, 0-9, +, /) to encode data, making it safe for text-based protocols.

Does it support Unicode and emoji?

Yes. The tool uses TextEncoder/TextDecoder to handle full Unicode text including emoji, CJK characters, and other non-ASCII content — unlike plain btoa() which only works with Latin-1.

Is there a size limit?

No hard limit. Everything runs in your browser, so very large inputs may slow things down, but there is no server-side restriction.

Is my data safe?

Yes. All encoding and decoding happens locally in your browser. No data is sent to any server.

Why is Base64 output ~33% larger than the input?

Base64 encodes every 3 bytes of input into 4 ASCII characters. This 4:3 ratio means the encoded output is always about 33% larger than the original binary data.

Can I decode any Base64 string?

The tool decodes standard Base64 strings. If the input contains invalid characters or incorrect padding, an error message will be shown.