Base64 Encoder

About Base64 encoder

Turns any text you type into a Base64 string, the ASCII-only format used in data URIs, email attachments, HTTP Basic authentication headers and JSON fields that cannot carry raw bytes. Accented letters, non-Latin scripts and emoji are converted to UTF-8 bytes first, so the output matches what server-side libraries produce for the same text. A switch selects the URL-safe Base64url alphabet, and a second switch controls the equals-sign padding.

How to use it

1. Leave the Encode tab selected at the top of the tool, since it is the tab the page opens on.
2. Type or paste your text into the box labelled Text to Encode.
3. Decide on the alphabet. Leave the URL-safe switch off for standard Base64, or turn it on for Base64url, which uses a hyphen and an underscore instead of a plus and a slash.
4. Check the padding switch. It starts on for standard output and switches itself off when you choose URL-safe, and you can flip it either way.
5. Press Encode to Base64. The button stays disabled until the box contains something.
6. Read the string in the Base64 Encoded Result panel and use its Copy button to put it on your clipboard.

One emoji in both alphabets

Hello, World! 😀

Standard with padding: SGVsbG8sIFdvcmxkISDwn5iA
For the emoji alone (😀): standard 8J+YgA==, URL-safe without padding 8J-YgA
The word café: Y2Fmw6k=

When to use it

• Building an Authorization: Basic header by encoding username:password before adding it to a request.
• Storing a short XML or JSON snippet in a setting that only accepts plain, safe characters.
• Preparing a Base64 field for a hand-written API test or webhook payload.
• Seeing for yourself how much a value grows, since the encoded form is roughly a third longer.

Questions about Base64 encoder

Why does my result end in one or two equals signs?

Base64 consumes input three bytes at a time and writes four characters for each group. When the last group is short, = characters pad the output to a multiple of four. Hello, World! is 13 bytes, so it finishes with two of them.

How are characters like é or emoji handled?

The text is turned into UTF-8 before encoding, so é occupies two bytes and café encodes to Y2Fmw6k=. The browser's bare btoa function would throw an error on anything beyond Latin-1, which is why this tool adds that extra step.

Does Base64 protect a password or token?

No. It is a reversible re-spelling of the same bytes, and anyone can undo it in one step. Treat an encoded secret exactly like the plain one and never rely on it for confidentiality.

Can I put the output straight into a URL?

Yes, with the URL-safe switch on. The standard alphabet uses plus, slash and equals, which all mean something in a URL, while the URL-safe output swaps in a hyphen and an underscore and omits the padding, so it is safe in a path segment or query value.

Is my text sent to a server?

No. The conversion runs inside your browser tab with built-in functions, so the text you paste never travels anywhere.

Related tools

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• Image to Base64Transform an image input to a Base64 string.
• URL encoderEncode any string input to URL format.
• Base64 to ImageDecode Base64 input to an image.
• Binary converterConvert text to binary and the other way for any string input.
• Hex converterConvert text to hexadecimal and the other way for any string input.