🔐Base64 Encoder / Decoder
Convert between text and Base64. URL-safe option supported, with automatic Korean handling. Useful for analyzing API auth tokens, JWT payload decoding, email attachment debugging, and safe data transmission encoding.
🔒 Browser-based✓ No watermark✓ No signup
How to use
- 1Enter text (or Base64) on the left.
- 2Conversion result appears instantly on the right.
- 3Copy to clipboard with the copy button.
FAQ
Can it encode Korean?+
Yes. Internally encodes as UTF-8 first, then Base64.
What's URL-safe Base64?+
A variant that's safe in URLs — replaces '+/=' with '-_'. JWT uses this.
Is Base64 for security?+
No. It's just encoding — anyone can decode. Sensitive info needs separate encryption.
Why is it ~33% bigger?+
Base64 encodes 3 bytes as 4 characters (base 64). Output is always about 4/3 of the original.
What about images as Base64?+
Use the dedicated Image ↔ Base64 tool for inline image embedding.
Why is decoding garbled?+
Common causes: (1) URL-safe Base64 decoded in standard mode, (2) missing padding (=), (3) double encoding.