yEnc Encode & Decode
An efficient Usenet encoding that saves size (=ybegin/=yend). This tool does both encode and decode on one page — just pick a mode, paste your text, and click. Everything runs on your device, nothing is sent to a server.
Everything runs in your browser. Your data is never sent to our servers.
Example
Example Input
Cat
Example Output
=ybegin line=128 size=3 ~ =yend size=3
How to Use
- 1Choose Encode or Decode mode at the top.
- 2Type or paste your text into the Input field.
- 3Click the button (or press Ctrl+Enter) to process. The result appears in the Output field.
- 4Click Copy to copy the result, or "Swap input/output" to quickly reverse the operation.
About yEnc
yEnc is a binary-to-text encoding designed for Usenet, much more efficient than UUencode or Base64 because it adds only a small overhead (~1–2%).
How it works: each byte is shifted by 42 (mod 256); only certain critical bytes (NUL, LF, CR, =) are escaped with "=". The result is wrapped in "=ybegin"/"=yend" lines. Because most bytes are unchanged, size is saved.
yEnc is popular for sharing binary files in Usenet newsgroups. This tool is useful for encoding/decoding yEnc payloads, though for general use Base64 is more portable.
FAQ
Can this yEnc tool both encode and decode?
Yes. This is a single page with a toggle — use Encode mode to transform text, and Decode mode to reverse it. No need for two separate pages.
Is my data sent to a server?
No. yEnc is processed entirely in your browser. The text you enter never leaves your device.