What is Base64 used for?
Base64 represents binary or text data using only ASCII characters, commonly used in data URLs, email attachments, and API tokens. This tool handles Unicode text correctly.
Base64 Encoder / Decoder
Switch between encode and decode to convert text to and from Base64.
How it works
- 1
Paste the value to encode or decode.
- 2
Pick the direction / algorithm if the tool has modes.
- 3
Copy the output. Decoding is not the same as verifying a signature.
Why use this tool
- Runs entirely in your browser — nothing is uploaded to a server.
- 100% free, no sign-up, no limits.
- Works in any modern browser — no app install, no extension, no account.
How to use Base64 Encoder / Decoder
Use Base64 Encoder / Decoder to transform encodings in your browser. If you decode a JWT or similar token, that does not prove the signature is valid.
Tips for better results
Watch for padding and character-set issues. Never paste production secrets into a shared screen.
Privacy and offline-friendly processing
Whenever possible, Base64 Encoder / Decoder processes your data locally with JavaScript in this page. That means drafts, secrets, and unfinished work stay on your device by default. Prefer this workflow when you do not want to upload sensitive text, tokens, passwords, or files to a third-party service.
Frequently asked questions
Can I encode emoji or non-Latin text?
Yes, the tool uses UTF-8 encoding so any Unicode text round-trips correctly.
What happens with invalid Base64 input?
Decoding shows a clear error message instead of garbled output.
Is my data uploaded when I use this tool?
For most FlyUtils tools, no. Processing happens in your browser with JavaScript. If a tool ever needs a server, that will be stated clearly on the page.
Is Base64 Encoder / Decoder free to use?
Yes. Base64 Encoder / Decoder is free, with no sign-up and no artificial usage caps for normal personal and work use.
Does Base64 Encoder / Decoder work on mobile?
Yes. The page is mobile-first, so you can paste input, tweak options, and copy results from a phone or tablet.