Base64 Encode / Decode

How to use the base64 encode / decode

1. Paste plain text to encode, or a Base64 string to decode.
2. Click Encode or Decode.
3. Copy the output.

About this tool

Base64 turns binary or text data into plain ASCII characters, which is how tokens, email attachments and data URIs are usually carried. This tool encodes and decodes UTF-8 text correctly, including accented letters, Indian scripts and emoji, and accepts URL-safe Base64 with - and _ characters.

Examples

Base64 reads the data three bytes at a time and writes four characters for each group. When the data does not fill the last group, one or two = signs are added as padding, which is why some results end with = or ==.

Why the result is bigger

Four output characters carry three bytes of input, so Base64 text is about 33% larger than the original. That is the price for using only letters, digits, + and /, which survive email systems, JSON strings and URLs that would mangle raw bytes.

Where you will meet it

• Data URIs, such as images embedded directly in CSS or HTML.
• HTTP Basic authentication, where the header carries Base64 of username:password. That is encoding, not protection, so only use it over HTTPS.
• Email attachments, which are Base64-encoded inside the message.
• JWT tokens, which use the URL-safe variant of Base64.

Base64 is not encryption

Anyone can decode Base64 in a second, as this page shows. Never use it to hide passwords, keys or personal data. If you need secrecy, use real encryption.

URL-safe Base64 and common errors

The URL-safe form swaps + and / for - and _ and often drops the = padding. This tool accepts both forms when decoding. If decoding fails, the usual causes are stray spaces or line breaks (email systems wrap lines at 76 characters), a missing character from copying, or text that was not Base64 to begin with. This tool handles text, so for files use a command-line tool or a file-based converter.

Frequently asked questions