About Base64 Encode
Base64 turns arbitrary bytes into a string made only of 64 printable characters — the letters A–Z and a–z, the digits 0–9, plus + and /. It exists because many systems were designed to carry text and cannot be trusted with raw binary: email bodies, JSON values, XML documents, HTTP headers and data URIs all fall into that category. Base64 is the standard way to move binary data through them safely.
This encoder is UTF-8 aware. That detail matters more than it sounds: it means Chinese, Japanese, Cyrillic and emoji survive the round trip intact. A non-UTF-8-aware encoder works on raw 16-bit code units and will silently mangle anything outside the Latin range — which is why so many online encoders turn "你好" into garbage.
The output is roughly 33% longer than the input, because three input bytes are carried by four output characters. That overhead is the price of text-safety, and it is the main reason Base64 is not used for storage you control end to end.
How to use Base64 Encode
- 1 Paste or type the text you want to encode into the input box.
- 2 The Base64 result appears immediately as you type — there is no button to press.
- 3 Click Copy to put the encoded string on your clipboard.
Frequently asked questions
Is Base64 a form of encryption?
No. Base64 is an encoding, not encryption — it uses no key and can be reversed by anyone. Its purpose is to make binary data survive text-only channels, not to keep it secret. If you need confidentiality, use encryption such as AES and transmit over HTTPS.
Why is the encoded output longer than my input?
Base64 represents every 3 bytes of input as 4 characters, so the encoded form is about 33% larger. When the input length is not a multiple of 3, the output is padded with = characters to keep it aligned.
Will Chinese characters and emoji survive?
Yes. The text is first converted to UTF-8 bytes and only then encoded, so multi-byte characters round-trip correctly. This is the main difference between this encoder and simpler ones that operate on raw UTF-16 code units.
Why does the result sometimes end with one or two equals signs?
Those are padding characters. Base64 works in groups of 3 input bytes; if your input is 1 or 2 bytes short of a full group, = fills the gap so the output length stays a multiple of 4. The padding carries no data and can be stripped if the receiving system does not expect it.
Free, online, and private
Free to use
Base64 Encode is completely free. There is no account to create, no login, and no hidden charge or usage limit.
Runs online in your browser
It is a free online tool that runs entirely in your browser. Nothing to download or install — open the page and start using it right away.
Your data stays private
All processing happens locally on your device. Your input is never uploaded, stored, or tracked, so it never leaves your browser.
How Base64 Encode behaves in detail
These are the specifics of this implementation — the exact ranges, defaults and fixed settings you are working with.
| Parameter | Value |
|---|---|
| Encoding | UTF-8 first, then base64 |
| Alphabet | standard (+ and /), padded with = |
| Non-ASCII input | handled — multibyte characters are encoded as their UTF-8 bytes |
Compiled from the implementation of this tool and checked against it by itoolnet.
What Base64 Encode does not do
Knowing the edges of a tool saves more time than another list of its features. These are the cases where it will not do what you might expect.
- The output uses the standard alphabet with + and /. If you need the URL-safe variant that substitutes - and _, the Base64 URL Encoder produces that form.
- There is no line wrapping. Some older mail and PEM formats expect base64 broken at 76 characters, which you would have to add downstream.
Tested and documented by itoolnet, the team that builds and maintains this site.