Base64 Documentation

Encode and decode UTF-8 text directly in your browser.

Browser APIs encode UTF-8 text using either the standard or URL-safe Base64 alphabet. URL-safe output omits padding. Decoding validates the selected alphabet and decoded UTF-8 text; ASCII whitespace is accepted. The Advanced panel converts one value per line and reports the line number if any value fails.

• Encode or decode a single value for debugging an API payload.
• Convert a list of values in bulk using batch mode.
• Inspect Base64-encoded data before pasting it elsewhere.

Input

Text, files, or values entered in the browser, depending on the tool.

Output

A result shown in the browser that can be reviewed or copied where supported.

• This is a UTF-8 text codec, not a binary-file converter or encryption tool.
• Unpaired JavaScript surrogate characters are normalized by TextEncoder. Base64 is encoding, not encryption.

Inputs for this browser-side tool are processed locally and are not sent to SiteIndex. Normal page analytics may still be collected as described in the Privacy Policy. Read the Privacy Policy.