Base64 Encode & Decode
This Base64 tool encodes text to Base64 and decodes Base64 back to text, right in your browser. Paste your text, pick encode or decode, and you'll get the result instantly with a copy button. It handles full Unicode through UTF-8, so emoji and any language survive the round trip, and since it runs locally, nothing you paste is ever sent anywhere.
- Encode to Base64
- Decode to text
- Full Unicode & emoji
- Validates input
- Private in your browser
Last updated June 17, 2026 Encoding, not encryption Reviewed by the Calcowa team
What is Base64 encoding?
Base64 turns any data into a string of 64 safe characters, the letters A to Z and a to z, the digits, plus and slash. It works by taking three bytes at a time, 24 bits, and splitting them into four six-bit chunks, each mapped to one character, with an equals sign padding the end when the bytes don't divide evenly. That's why Base64 is roughly a third larger than the original. The point is portability: it lets binary or Unicode text ride safely through systems that only handle plain text, like JSON, email, and data URLs, so it won't get mangled in transit. This tool encodes and decodes through UTF-8, so it's safe for any language, and it's an encoding rather than encryption, so it's for transport, not secrecy.
Encoding the word Hello
Here's how Hello becomes SGVsbG8=. It's the same path the tool runs for any text:
- 1
Read the bytesHello is five UTF-8 bytes: 72, 101, 108, 108, 111.
- 2
Group into sixesThose bits regroup into six-bit chunks instead of eight.
- 3
Map to charactersEach chunk becomes one of the 64 Base64 characters.
- 4
Pad the endSince five bytes do not divide by three, an equals sign pads it, giving SGVsbG8=.
Text and its Base64
Here are a few short strings with their Base64, so you can see the pattern and the padding. The tool encodes any length for you.
| Text | Base64 |
|---|---|
| A | QQ== |
| Hi | SGk= |
| Hello | SGVsbG8= |
| Calcowa | Q2FsY293YQ== |
| 123 | MTIz |
Frequently asked questions
Type or paste your text and the tool encodes it to Base64 the moment you stop typing. Behind the scenes it reads your text as UTF-8 bytes and maps every three bytes to four Base64 characters, so any language or emoji encodes cleanly. So the word Hello becomes SGVsbG8=. Hit copy to grab the result, and nothing you paste ever leaves your browser.
Switch to decode mode and paste the Base64 string, and you'll get the original text back. The tool reverses the mapping, turning each four Base64 characters into three bytes, then reads those bytes as UTF-8. If the string isn't valid Base64, it flags the error rather than showing garbage, so you'll know straight away that something is off.
Base64 packs binary data, like an image or a file, into plain text that's safe to drop into places built for text: email bodies, JSON fields, data URLs, and HTML. It isn't encryption and adds about a third to the size, so it's for transport and embedding, not security. Developers reach for it constantly when a system only accepts text.
No, and that's an important point. Base64 is an encoding, not encryption, so anyone can decode it back to the original in seconds, exactly as this tool does. It hides nothing and protects nothing. If you need to keep data secret, use real encryption; Base64 just reshapes data into a text-safe form for moving it around.
Yes. The tool encodes through UTF-8, so accented letters, non-Latin scripts, and emoji all survive the round trip intact. Plain browser encoding can choke on those characters, but the UTF-8 step here handles them, so you can encode and decode any text without it breaking on a special character.
Yes to both. There's no sign-up, no limit, and nothing to install, since it runs entirely in your browser. Whatever you encode or decode stays on your device and isn't sent to a server, which matters when you're handling real tokens or data. Bookmark it and you'll have a quick, safe Base64 converter ready.
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