Code & Data
Base64 encode anything, including emoji
Paste text and get Base64. It handles emoji, accents and non-Latin scripts correctly — which the browser’s own btoa does not, because it throws on anything above U+00FF.
Text is encoded as UTF-8 first, so emoji, accents and non-Latin scripts all work. The browser’s own btoa throws on those.
Type above and the Base64 appears here.
- Runs in your browser
- No account required
- Free to use
How it works
Text becomes UTF-8 bytes first
Base64 encodes bytes, not characters, and the missing step in most implementations is deciding which bytes. The browser’s btoa assumes one byte per character and throws the moment that is untrue — on an emoji, on Chinese, on a curly quote pasted out of a word processor. Encoding as UTF-8 first is what makes the output match every other Base64 implementation.
The URL-safe alphabet exists for a reason
Standard Base64 uses + and /, both of which are meaningful inside a URL — a token containing them breaks when pasted into a query string. RFC 4648 defines a variant using - and _ instead, which is what JWTs and most APIs use.
Padding is sometimes required and sometimes rejected
The trailing = characters pad the output to a multiple of four. Some APIs insist on them, some reject them, and JWTs omit them entirely — so it is a switch rather than an assumption.
What it does
Works on any text
Emoji, accented characters, Arabic, Chinese and Cyrillic all encode correctly and decode back to exactly what you typed.
URL-safe, unpadded and wrapped
Three switches covering the variants people actually need: query strings and JWTs, and the 76-character wrapping used by email attachments.
The size cost, shown
Base64 is about a third larger than the data it encodes. Both figures are shown, which matters when the result is going somewhere with a size limit.
Your data never leaves the page
API responses, config files and exports are exactly the sort of thing that should not be pasted into someone else’s server. Parsing happens in your browser and what you paste is never transmitted — there is no code here that could send it anywhere, even by accident.
Practical advice
Getting a better result
- Base64 is encoding, not encryption. Anyone can decode it in one step — never use it to hide anything.
- If an API rejects your token, check the padding first. It is the commonest incompatibility.
- For a value going into a URL, use the URL-safe alphabet or the + and / will need escaping anyway.
- The output being a third larger is inherent to the format: three bytes always become four characters.
Questions
Things people ask
Why do other Base64 tools fail on emoji?
Because they call the browser’s btoa, which is defined over characters in the range 0–255 and throws on anything above it. An emoji, a Chinese character and a curly quote all exceed that. Encoding to UTF-8 bytes first avoids the problem entirely, and produces the same output every other language’s Base64 does.
What is URL-safe Base64?
A variant using - and _ where standard Base64 uses + and /. Both of those have meaning inside a URL, so a standard-encoded token can break when pasted into a query string. JWTs use the URL-safe alphabet, usually without padding.
Is Base64 secure?
No. It is an encoding, designed to move binary data through text-only channels, and it is reversible by anyone in a single step. It offers no confidentiality whatsoever.
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