Nyan Cat Telnet Server

After two months on EC2, we've now moved to DigitalOcean. - March 31, 2014

This is an animated, color, ANSI-text telnet server that renders a loop of the classic Nyan Cat animation. (Mirrors)

As with nearly everything I make, this is open source (NCSA license) and available on github (klange). You can also follow me on Twitter (@kevinlange). Watch Nyan Cat on a VT220

Open up a supported terminal^ and run:

telnet nyancat.dakko.us

Or you can click here on some browsers.

Nyan Cat Buy this CD!

Don't see poptart cat? Check the terminal support notices and caveats below.

[Nyan Cat]
Screenshot from gnome-terminal

In addition to telnet, netcat may also work. Check which version of netcat you're using and note that you can't tell netcat what terminal to report so you will always get "ansi" mode (non-xterm-256-color, uses "10X" for bright backgrounds).

BSD   nc -v nyancat.dakko.us 23
GNU   nc -T nyancat.dakko.us 23

Supported Terminals

Should work on all of the following (assuming at least an 80x24 terminal):


If you get bad output

If you are using a modern terminal which reports itself as xterm or similar and you don't see Nyan Cat, try:

TERM=ansi telnet nyancat.dakko.us

If everything else fails and you know your terminal supports at least standard ANSI escapes (color), try:

TERM=fallback telnet nyancat.dakko.us

If that gets the colors right, but you don't support unicode, try one of the following:

TERM=linux telnet nyancat.dakko.us # For background-only, prints spaces
TERM=vtnt telnet nyancat.dakko.us  # Foreground, uses extended ASCII block characters

If you are on Windows and using the native terminal, try this:

telnet -t vtnt nyancat.dakko.us

If the server isn't responding

Shoot me an email: langek (A) acm (D) org
Or let me known on Twitter: @kevinlange

The server is set up to run with inetd and should be fairly stable by now, but if something does happen, let me know and I'll try to bring everything back online.


The server is written in C and runs with inetd. It does not make use of ncurses or other terminal libraries, but rather writes raw ANSI escape sequences after being given a terminal type, which telnet passes as part of its handshake. It was originally written for my personal operating system.

The server running the service is part of the UIUC ACM cluster.

If your connection is lost during a successful run, it's probably because I restarted the server.


Nyan Cat was originally made by prguitarman.


As stated previously, code is up on Github at klange/nyancat. I am accepting changes if they are worthwhile and improve the overall experience.

The application behind the telnet server was originall written for my toy OS. I was presented with the idea of making it a telnet server by friend and colleague Mike Lynn. It took about an hour of work to set up the animation to run at the right size (80x24), work on various terminals, and execute from a telnet connection.


There are currently no known operating mirrors. There used to be a few, but they've all disappeared. Here's a list of domains that used to host telnet nyancat:

ebal.ee 666

More Screenshots

Nyan Cat on something that doesn't claim to be XTerm.
Results when a terminal does not claim to be xterm.*.

Nyan Cat on the fallback terminal
Results for the fallback terminal type, ugly but effective.

Nyan Cat on an iPad
Nyan Cat on an iPad with iSSH.

Newer fallback
Newer fallback terminal output, a lot less ugly. Uses ASCII block characters.

Inside of LXTerminal
Running under LXTerminal, the default terminal for LXDE.

Under Windows with telnet -t vtnt nyancat.dakko.us

XFCE Terminal
That Nerd sent me this pic of XFCE4 Terminal under Arch.

iPod Touch
iSSH on an iPod Touch via @B4rr0

Terminator, Mint
Terminator on Linux Mint via @Peetz0r

ConnectBot, Android
ConnectBot on Android, also via @Peetz0r

Another Connectbot
Another Connectbot picture, via @anthonydfhogan

OS 10.7, Terminal.app
Mac OS 10.7 Terminal.app via @iamjoeodell

VT220, video

VT220 updated
Updated VT220 palette for better color accuracy.

AJAXTerm under Opera, once more via @Peetz0r

Shell in a Box under Firefox
Shell in a Box (web terminal) under Firefox

XTerm on an HP TouchPad
XTerm on an HP TouchPad via @nicktabick

iTerm on OS X Lion
iTerm on OS X Lion, via @macjunkie

Nyan Cat on Cathode, a retro terminal emulator for OS X, via @charliesome

Apple ][ screensaver
Nyan Cat in the Apple ][ XScreenSaver, modified by @Peetz0r

Updated Gnome Terminal
An updated screenshot of Gnome Terminal with a timer.

A 386-40 (running DOS 5) and an IBM PCjr (from 1986, running DOS 3.3) both using mTCP to connect to the telnet server, via Mike Brutman (by email)

Room full of Nyancats
An entire room full of terminal Nyan Cats, celebrating Nyan Cat's birthday, via loraxx753 on reddit.

It even works in OS/2!

froggey's hobby OS
In froggey's hobby OS

From an old friend, on an Omate Truesmart.

I am collecting screenshots. If you would like to show me how nyancat looks under your setup, tweet me @kevinlange. I'm using gnome-terminal. If your setup isn't special I might not add your pics, sorry :( .

Copyright 2011-2014 Kevin Lange
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