Base64 Encode / Decode
UTF-8 safe Base64 encoding and decoding — including the URL-safe alphabet used by JWTs.
How it works
Encoding first converts your text to UTF-8 bytes, so Chinese, emoji and other non-ASCII
characters round-trip correctly — unlike naive btoa-only converters. Decoding is
whitespace-tolerant: line breaks and spaces in the input are ignored. The URL-safe option
swaps +// for -/_ and drops padding,
matching the Base64url used in JWTs.
FAQ
Is Base64 encryption?
No — it is a reversible encoding with no secret. Anyone can decode it. Use the AES tool when you need confidentiality.
Why does my decoded text look garbled?
The input probably was not UTF-8 originally (e.g. Latin-1 or GBK bytes). This tool decodes as UTF-8, the web standard.
Is my data uploaded?
No. Everything runs in your browser.
Base64 Encode / Decode — FAQ
Is Base64 Encode / Decode free to use?
Yes. It is completely free, with no signup, no installation and no usage limits.
Is my data uploaded to a server?
No. The tool runs entirely in your browser — the data you paste or upload never leaves your device.
Does it work on mobile devices?
Yes. It works in any modern desktop or mobile browser, with nothing to install.