🔐 Base64 Encoder / Decoder
Instantly encode text to Base64 or decode Base64 back to plain text — free, runs entirely in your browser, no file upload required, and works offline.
Text
Base64
Private by design. This tool runs entirely in your browser — nothing you enter is uploaded or stored, and it works offline.
About
This tool converts text to and from Base64 encoding directly in your browser using the Web Crypto APIs — your data never leaves your device. It supports full UTF-8 input including Korean, Japanese, and emoji, plus a URL-safe mode that replaces + and / with - and _ and strips padding for use in URLs and filenames. Your last input is automatically saved in localStorage so you can pick up where you left off.
How to use
- Paste or type your plain text into the top Text panel.
- (Optional) Check 'URL-safe' if you need the result safe for use in URLs or filenames.
- Click 'Encode ↓' to convert text to Base64; the result appears in the Base64 panel below.
- To decode, paste a Base64 string into the bottom panel and click 'Decode ↑'.
- Use the Copy buttons to copy either result to your clipboard.
FAQ
- Is this Base64 tool free?
- Yes, completely free with no account or subscription required.
- Does it upload my data to a server?
- No. All encoding and decoding happens locally in your browser. Nothing is ever sent to any server.
- Does it work offline?
- Yes. Once the page is loaded, it works without an internet connection.
- Does it support Korean and other non-ASCII characters?
- Yes. The tool uses UTF-8 safe encoding, so Korean, Japanese, emoji, and any Unicode text is fully supported.
- What is URL-safe Base64 and when should I use it?
- URL-safe Base64 replaces + with - and / with _ and removes padding (=), making the output safe to include directly in URLs or filenames without percent-encoding. Use it for JWT tokens, URL parameters, or file naming schemes.