Does Base64 encrypt or protect my data?

No. It is a reversible encoding with no key, and decoding is instant for anyone who has the string. Never use it to hide a secret — use it to move bytes through a text-only channel.

Why is my encoded text about a third larger?

Base64 represents every three bytes as four characters, which is a 33 per cent increase by design, plus up to two characters of padding. The figures above the result show the exact overhead for your input.

What is the URL-safe alphabet for?

Standard Base64 uses + and /, which have meaning inside URLs and filenames. The URL-safe variant substitutes - and _ so the value can be dropped into a path or query string unchanged.

Can it encode emoji and non-English text?

Yes. The text is encoded as UTF-8 first, so any Unicode character works. This is a real difference from tools built on the browser's btoa function, which fails on anything above U+00FF.

No. Encoding happens in your browser, so pasting a token or a credential here does not transmit it anywhere.

Base64 Encode

Turn text into Base64, with optional URL-safe output.

Everything runs inside your browser. Your files never leave your device.

Input

Result

The result appears here as you type.

Ask about Base64 Encode

Questions about what this tool does, which option to pick, or what it can and cannot handle.

This is the one part of the site that uses a server. The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong; the tool itself is not guessing.

About the Base64 Encode

Base64 turns arbitrary bytes into sixty-four printable characters, so that data which is not text can travel through channels that only carry text. Email attachments, data URIs, JWT segments, basic authentication headers, certificates in PEM form, small images embedded directly in CSS — all of them are Base64 underneath.

It is an encoding, not encryption. Anyone can decode it in a second, and this tool has a button for exactly that. Base64 makes data transportable; it makes it no more private than it was.

Two options here matter in practice. The URL-safe alphabet replaces the plus and forward slash with hyphen and underscore, which is what you need when the encoded value goes into a URL path, a query string or a filename — the standard alphabet would otherwise need percent-encoding on top and produce something unreadable. The padding switch removes the trailing equals signs, which several specifications including JWT require you to omit.

Encoding runs through a proper UTF-8 encoder rather than the browser's raw btoa, which throws an exception on the first character above U+00FF. That means accented letters, emoji, Japanese and every other script encode correctly here, where a naive implementation would fail outright.

How to use it

1Paste or type the text you want to encode into the input box.
2Turn on the URL-safe alphabet if the result will go into a URL, a query string or a filename.
3Turn off padding if the specification you are working to requires the equals signs removed — JWT does.
4Copy the Base64 result, or download it as a text file.

Questions

Does Base64 encrypt or protect my data?: No. It is a reversible encoding with no key, and decoding is instant for anyone who has the string. Never use it to hide a secret — use it to move bytes through a text-only channel.
Why is my encoded text about a third larger?: Base64 represents every three bytes as four characters, which is a 33 per cent increase by design, plus up to two characters of padding. The figures above the result show the exact overhead for your input.
What is the URL-safe alphabet for?: Standard Base64 uses + and /, which have meaning inside URLs and filenames. The URL-safe variant substitutes - and _ so the value can be dropped into a path or query string unchanged.
Can it encode emoji and non-English text?: Yes. The text is encoded as UTF-8 first, so any Unicode character works. This is a real difference from tools built on the browser's btoa function, which fails on anything above U+00FF.
Is my text uploaded?: No. Encoding happens in your browser, so pasting a token or a credential here does not transmit it anywhere.