Base64 Encode/Decode

Base64 Encode/Decode converts text and files to Base64 and back. Everything runs in the page, so API keys, tokens and config snippets never leave your machine — you can confirm that by watching your browser's network tab while you use it.

How to use

1. Paste your text into the input, or drop a file onto it.
2. Pick a direction: encode to Base64, or decode from it.
3. The result appears immediately and can be copied with one click.
4. For files, the output is a data URI you can paste straight into HTML or CSS.

Where Base64 shows up

• Embedding a small image or font directly in CSS or HTML as a data URI, avoiding an extra network request.
• Reading the payload of a JWT to check what claims a token actually carries.
• Basic authentication headers, which are the string user:password encoded in Base64.
• Email attachments and MIME, which have used Base64 to move binary data over text-only channels for decades.
• Storing binary blobs in JSON or a database column that only accepts text.

What Base64 is and is not

Base64 is an encoding, not encryption. It maps every three bytes onto four printable ASCII characters so binary data survives channels that only handle text, and anyone can reverse it instantly — never use it to protect a secret. The transformation also costs roughly 33 percent in size, which is why embedding large images as data URIs usually makes a page slower rather than faster. Text is processed as UTF-8, so accented characters, CJK and emoji all round-trip correctly.

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FAQ

Does Base64 Encode/Decode send my input to a server?

No. The conversion runs in JavaScript inside the page, so API keys, tokens, config files and any other sensitive text stay on your machine. You can verify this by opening your browser's network tab while you use the tool.

Does Base64 Encode/Decode handle Unicode and non-ASCII characters?

Yes. Text is processed as UTF-8, so accented Latin, Korean, Japanese, Chinese, Cyrillic, Arabic and emoji all round-trip correctly rather than turning into question marks.

Can I use the output in production code?

Yes — the output follows the relevant standard exactly and is safe to paste into your project. As with any tool, run your own tests before shipping anything that depends on it.