Browser-local developer conversion

Base64 Decoder & Encoder

Decode Base64 into inert UTF-8 text or encode Unicode text into Base64 without uploading it. A separate mode supports the Base64URL alphabet and omitted padding.

Enter a value to begin.

Unicode and binary behavior

Encoding uses UTF-8 bytes, so emoji, accented text, Chinese, Japanese, Arabic, and surrogate pairs round-trip correctly. Non-UTF-8 decoded bytes are not rendered as text; a bounded hexadecimal preview and local binary download are offered instead.

Inert output and Base64URL

Decoded HTML, scripts, SVG, data URLs, and links remain inert text and are never executed or opened. Base64URL is an explicit mode using - and _ with optional omitted padding; it is not ambiguously auto-detected.

Examples and limits

Try aGVsbG8= to decode hello. All interactive processing remains browser-local.

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