Where to play Leela online?

The play.lczero.org web site where everyone could quickly play Lc0 online is currently down.

But even while it doesn't work, there are some options to play Leela online.

The easiest way is to play on lichess.
You can pick one of the Leela Chess Zero bots:

  • LeelaChess -- full-strength bot which is kept reasonably up to date.
  • LeelaNice -- the bot configured almost not to think. It still very strong, but sometimes misses non-trivial tactics, which makes it possible to win.
  • MiniHuman -- distilled 48x5-se network from id11258 (small network learnt from large Leela net), played on Raspberry Pi 3 with almost no thinking.
  • leela2200 -- distilled 112x9-se network from id11258, running on CPU.
Also there are other bots of different configurations and strength. Check the all-the-leelas lichess team and pick the one which is online. You are also welcome to host your own Leela and join that team.

If you know other ways to play Leela online (FICS, etc), please reply in comments, I'll add it to this post.

And of course you can always download Leela and set it up to play locally. This blog post describes how to do that.

UPD: Kontrachess has a way to play with LCZero. It seems very to be very nice looking site! I did not try it myself though. (Initially I thought it was a paid site, but one of the site representatives said in comments below that it's actually free).

UPD2: Also NextChessMove has a number of options including different networks of Lc0. From what I can see, it is similar to what play.lczero.org was. It takes some time to get a move from a free version, but probably paid version is faster (again, I don't know anyone who tried that).


  1. Replies
    1. Kontrachess is only a *partial* solution. It has very strict time limits. I prefer to linger over games for hours or even days (even weeks) for study. Yet Kontrachess times out after 30 minutes (MAXIMUM) and so I feel RUSHED and LEARN LESS. You may say "Just bring up your own copy of Leela" - that is MUCH easier said than DONE. I don't run Windows (as a matter of fact) and my attempts to bring up Leela (which has a horrible installation and readme, just awful with absolutely no thought given to the convenience of the end-user-player) have failed. If anyone wants to punch my nose for saying these things, feel free, but only if you've brought up Leela on a current version of Apple Mac OS X or Ubuntu Linux.

    2. Which operating system do you run?

    3. I totally agree with you on how hard it is to install leela. I have a windows computer and I spent hours on it and couldn't figure it out. If they really wanted leela to get better, they would make it as easy as possible to install so that more people would use it.

    4. I have now brought up Leela on AWS with Ubuntu+GPU and AWS with Windows 10+GPU and on Apple Mac with no GPU. All of them crush me and my weak grandmaster program I wrote.

  2. Will the website be discontinued or is it being fixed?

    1. People who set it up initially are not very active in a project recently.
      Other devs are currently working on higher priority tasks. It can happen at any time that someone volunteers to repair play.lczero.org though.

  3. Hi
    I would have two questions ...

    1) I downloaded the latest versions of the neural network (elo> 5600) and I did a minimatch with an lc0 that used the old neural network 11149 (elo 4751)
    4 games, with 30 sec per move
    To my surprise it wins lc0 with the old neural network (+3 = 1 -0)
    So what is the best neural network for lc0?
    The last neural networks reported a higher elo but LC0 is weaker!

    2) If Lc0 has reached too high an elo has effects on its neural network playing against relatively weak humans?
    Can not train the network playing against stockfish, komodo and Houdini?


  4. Why did the website stop working? What happened to it? What can we do to prevent something this this from ever happening again?

  5. Why is nobody working on this site??? Full weekend went by without having LEELA!!!

  6. If you want the website to come back why don't you fucking donate so it'll stay that way.

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  8. Hope you will get this wepsize up again :-)

  9. I just saw you linked to NextChessMove -- thank you!

    One important thing to note is that NCM does not have any GPU servers. (Yet.) So LcZero on NCM is restricted to running on CPUs. Paid members get stronger results from LcZero because their moves are calculated on 20 core servers instead of single core servers, but that still won't compete against LcZero running on a proper GPU.

    As far as the delay, that comes from 1) the think time which is 5 seconds for free users and selectable between 0-15 seconds for paid users, 2) network latency, and 3) downloading the network if NCM hasn't done so yet.

    So, while paid users can get faster results by reducing the think below 5 seconds, doing so results in weaker results.

    Thanks again, and let me know if there's anything I can clear up!

    1. Hi Chad, a few hours ago I bought the NextChessMove service for my computer.
      I played 5 games at 25 minutes and 10 seconds against Lc0 his maximum level in Kontrachess, I used the Stockfish engine in 20 cores with only 10 seconds to think and the result was 3 wins and two draws.

  10. would love for playleela to work again.

  11. I look forward to playing LC0 on this platform again. It was easy and convenient. Thank you.

  12. Bring Leela Back Please We need Leela to be able to trounce alpha zero!


    Hi all,

    Came across a thread where they were working on getting Leela running on Azure at the best price point. This discussion resulted in a nice setup document.

    The speed/results is directly on par with the popular Google Cloud service:
    Azure: 236 games in 1378 minutes
    gCloud: 229 games in 1188 minutes

    I get $150 a month in Azure, thinking of using it for Leela (if someone is willing to assist with the setup).

    Discussion Thread: https://groups.google.com/forum/#!msg/lczero/gH6zmsEdIFw/HW37z1kRCQAJ
    Documentation: https://docs.google.com/document/d/1DMpi16Aq9yXXvGj0OOw7jbd7k2A9LHDUDxxWPNHIRPQ/edit

  14. Hi, Pepe from Kontrachess.com here. We are not a paid service, and anyone is welcome to play our leela for free. We are a new chess site, currently in beta, which incorporates an in-game betting system where players can double the stakes at key moments in the game to put additional pressure on their opponents. Leela will "kontra" (double the game stakes) at the moment she thinks she winning. Playing leela doesnt actually affect your coin balance or rating. Please stop by and give her a try! We've been proud supporters of the Lc0 project from the beginning, contributing both resources and code, and we are extrememly excited to see what news doors AI technology will open for us in our understanding of chess!

    1. Thanks for the information, I've updated the text!

  15. Posted also at talkchess.com tonight.

    This was a 10 minute with +10 second increment time control.

    My program is single-thread, about 1M moves per second, with position and pawn hash tables and various extensions and reductions with quiescence.

    Very classical/traditional program.

    In this game, it is crushed by Leela in a positional maneuver on the kingside while my program's queen is wandering far from the action in a closed pawn position.

    This was played at kontrachess.com. Besides the above time control, Leela was set to "MAX", whatever that is.

    I don't know the version of Leela or much else but it shows the maneuvering style combined with my program's lack of positional understanding and tactical over-tendencies.

    My program scores about 2520 on the iq6 tactical test but is a anti-positional fool.

    g1f3 d7d5
    c2c4 d5d4
    d2d3 c7c5
    e2e4 b8c6
    f1e2 e7e5
    d1a4 f8d6
    c1g5 g8e7
    g5e7 d8e7
    b1d2 h7h5
    a1c1 h5h4
    e1g1 g7g5
    h2h3 g5g4
    h3g4 c8g4
    f3d4 e5d4
    e2g4 e7g5
    e4e5 g5g4
    e5d6 h8g8
    g2g3 h4g3
    d2e4 g4h3
    f2g3 g8g3
    e4g3 h3g3
    g1h1 e8c8
    d6d7 c8b8
    a4a7 b8a7
    f1f5 d8h8
    f5h5 h8h5

  16. Does anyone want to work with me (no cash involved) to bring up Leela Chess Zeros on our respective Apple Mac's and/or PC's and/or AWS Cloud? I will handle the costs of AWS. If interested, email me at [email protected]

  17. I paid for NCM(Next chess move) services. I selected LCo (experimental). I made my move e4. why is black not moving? how do i make LC play?

    1. You should click the gear ⚙ icon and turn on the checkbox 'Automatically execute moves returned by the engine',
      then Close. Next, check Active Color to 'Black to move'. Then, after each white move, click Calculate next move.
      Hope this helps.

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  19. Can leela chess run on a boinc program?

  20. I got Leela up on AWS Ubuntu w/ GPU and AWS Windows 10 w/ GPU and Mac OS X. The first two work fine. The latter makes illegal moves as far as I can tell and I don't see a good front-end to put in front of lc0. Anyone know of one?

  21. I played Borderlands Two recently and found it really unenjoyable. Clunky shooting, with bullet sponge enemies, annoying characters and a boring main story. Some of the side quests were funny, but all in all, I found it really boring and samey after completing the main quest line.
    Regards: Eve Hunt

  22. Please activate "Play lczero!"!

  23. I stood up Leela on my Mac (non-GPU) and on my AWS Ubuntu instance (with GPU) and with my AWS Windows 10 instance (with GPU), so I'm swimming in Leela here. If anyone wants help setting it up, let me know. I don't charge much!

  24. Where have I gone wrong? All I get is stockfish when I start a game from LeeleChess and LeelaNice links. Kontrachess just gives a black tab.

  25. someone has a 32 bit leela engine please upload it to mediafire i have a stockfish 9 32 bit engine the only one that sometimes wins is BrainFish_190120_32bit.exe with book Cerebellum_Light_Poly_SCCT.bin or send it to my email [email protected]

  26. If you like Chess game . you will try . I hope you Enjoy

  27. this game is very wonderfull and powerLLc game


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