Top 6 Best Chess Engines in the World in 2021

The best chess engines in the world in 2021 are:

  • Stockfish 13 – Elo 3546
  • Fat Fritz 2 – Elo 3526
  • Komodo Dragon – Elo 3495
  • Igel 3.0.5 – Elo 3418
  • RubiChess 2.1 – Elo 3407
  • Houdini 6 – Elo 3398
top 6 best chess engines of the world blogimage

The best chess engines today are almost unrecognizable to the ones a mere two years ago. The progressing technological advance changed the game of chess during the last few years.

In 1997 the IBMs supercomputer Deep Blue defeated the World Champion of those times, Garry Kasparov, in a chess match under tournament conditions.

It became obvious that artificial intelligence was on the rise!

Estimated reading time: 13 minutes

Our list of the Top 6 Best Chess Engines of the World in 2021

Today, more than 20 years since Deep Blue defeated Kasparov, chess engines have even become a lot stronger and increase in playing strength each year. This is partly due to the increase in processing power that enables calculations to be made to even greater depths in a given time.

In addition, programming techniques have improved enabling the engines to be more selective in the lines that they analyze and to acquire a better positional understanding. Even better than the World Chess Champion Magnus Carlsen. Nowadays, there is no human player who can beat one of the best chess engines.

Best Chess Engines in the World in 2021
Best Chess Engines in the World in 2021

1. Stockfish 13 – Elo 3546

Top 5 Best Chess Engines Of The World In 2018

Stockfish is the strongest free chess engine. It is easy to say that Stockfish 13 is well beyond the skill of any grandmaster.

Stockfish is an open-source UCI chess engine available for various desktop and mobile platforms. It is developed by Marco Costalba, Joona Kiiski, Gary Linscott, and Tord Romstad, with many contributions from a community of open source developers. 

In fact, GM Alec Colovic praised Stockfish after better understanding what happened on the board at the World Championship match between Magnus Carlsen and Fabiano Caruana. 

For him, it was easy to understand why Stockfish would be the top chess engine at the 2018 tournament, TCEC.

The best thing about Stockfish is that it is free, open-source, and cross-platform. 

At the moment, Stockfish 13 64-bit 4CPU has an Elo rating of an incredible 3546 points.

You can download Stockfish here:

 2. Fat Fritz 2 – Elo 3526

fat fritz 2 logo

Fat Fritz 2 is a newcomer on the scene. This chess engine was only released in February 2021 and Fat Fritz 1 in November 2019 as part of the Fritz 17 package. 

Fat Fritz 2 makes use of NNUE and Stockfish with a double-sized network. Thanks to new developments in AI technology, it can run on a CPU instead of requiring the expensive GPU graphics cards for game playing that its predecessor needed.

Combining NNUE with the powerful Stockfish move search, it is no surprise that this commercial chess engine has a rating very close to Stockfish 13. A mere 20 Elo separates the two of them.

Fat Fritz 2 is available for Windows 7 or higher. 

You can purchase it here:

3. Komodo Dragon – Elo 3495

img dragon 2x

Komodo is a UCI chess engine developed by Don Dailey, Mark Lefler and supported by chess author and evaluation expert GM Larry Kaufman.

The chess engine is a commercial one, but version 12 is free for non-commercial use. You will need a GUI as the download does not include a chessboard.

At the moment, Komodo Dragon has an ELO rating of 3495.

Komodo is available for Windows, Linux, and Mac OSX 10.7 or higher, 

You can buy the latest version of Komodo or get an older version for free here:

4. Igel 3.0.5 – Elo 3418

The name Igel is the German word for Hedgehog and was chosen because numerous hedgehogs lived in the developer’s garden.

Igel branched from GreKo in 2018 due to the developer wanting to learn new things and hopefully improve upon the chess engine.

Things did not start off well with Igel regressing, but poor results in TCEC season 15 (finishing last in Division 4a) provided the necessary motivation for the developer to turn things around.

Igel climbed steadily through the ranks until it is now ranked at number 4 in the CCRL list with a time control of 40 moves in 15 minutes.

This is a strong, free chess engine that runs on Windows, Linux, and Mac OS.

You can find out more about it and download the engine here:

5. RubiChess 2.1 – Elo 3407

Chess players today are fortunate to enjoy 3 free chess engines in the top five. RubiChess 2.1 being the third.

Fat Fritz 2 and Komodo Dragon are the two commercial engines in the top 5.

RubiChess is a UCI chess engine by Andries Matthies that started out as Ox88 engine back in 2017; the engine has evolved until it includes NNUE.

This latest advance was announced in September 2020.

RubiChess is available for Windows, x64 Linux, MacOS x64, and Raspbian until Raspbi 3 and 4.

Download RubiChess 2.1 here –

6. Houdini 6 – Elo 3398

Best Chess Engines in the World Houdini

Houdini is a UCI chess engine developed by Belgian programmer Robert Houdart. Earlier versions are free for non-commercial use (up to version 1.5a). Later versions – 2.0 and onwards – are commercial.

At the moment, Houdini 6 64-bit 4CPU has an ELO rating of 3398.

Houdini will run on recent Windows operating systems. On Linux computers, you can use Wine with little impact on the performance, and on Apple computers, a Virtual Machine will allow you to run Houdini. 

There are two versions of Houdini available:

  1. Houdini 6 Standard – for the majority of users with mainstream computers.
  2. Houdini 6 Pro – for high-end users.

The standard version supports up to 8 threads and 4 GB of hash, while the pro version supports 128 threads and 128 GB of hash memory.

You can purchase Houdini here:

Today, many chess players spend a lot of time working with computers. Any ambitious chess player can and should download at least one strong chess engine. Chess engines evolved to one of the most vital chess training tools.

Having a chess engine gives you the possibility to have a Super-GM at home who will give you his evaluation and the best move in any position you want.

Although there is a great variety of chess engines with different styles and strong points (and weak points also), most of them play better than any human player, so there is no better advice to take! And some of them are even free!

In essence, chess engines are a great chess training tool to have. If they are used correctly, they can help any chess player to improve. If not, the extensive use of chess engines can result in the stagnation of your playing ability and you might stop improving.

Therefore, firstly, we want to caution you a little against the topic of chess engines in the following article. Subsequently, we will present you the three best and latest chess engines which are available on the market.

Don’t Abuse Chess Engines

The use of chess engines is a complicated topic. The former World Chess Championship Contender Peter Leko once said that “in our modern computer era, it’s always a delight […] to stimulate our brains.” This means that in most cases, you’ll learn more and increase your understanding of chess by doing the work yourself.

However, it becomes more and more obvious that plenty of amateur chess players don’t think by themselves about a given chess position, but immediately start to look at the machine’s evaluation. These habits turn out to be fatal, as they keep you away from training your own chess skills.

If you analyze your games, it is extremely important to use your own brain and not solely the best chess engines!

Top 5 Best Chess Engines Of The World In 2018

Don’t be lazy and just let the machine tell you the best moves. You don’t have the computer on your side during your real games.

Invest your chess study time into a detailed analysis of your own games, especially the games you lost as you’ll learn more from them! In the end, you can ask for hints from the computer.

Sometimes, even the best players in the world can’t convert a position a computer evaluates to a +1.5 advantage. So, don’t rely on artificial intelligence but on your own brain!

Disadvantages of Using Chess Engines

There is one major downside of using chess engines! They don’t care about winning the game but try to achieve the highest possible assessment in their merit function.

A computer isn’t really interested in subjectively dangerous counterplay that objectively doesn’t pose a threat. Hence, it is vital not only to look for the move with the highest ranking while analyzing with chess engines but also to concentrate on the easiest way to win.

When you have the choice between a complicated mate in 8 moves sacrificing material and a simple way to win the opponent’s queen with an easily won position, you should always decide for the latter.

Unlike Chess Engines We Are Not Machines

People often have a tough time to turn objectively won positions into a full point. Thus, in winning positions it is essential to stay highly concentrated and to prevent counterplay, instead of traveling mentally to the calculation of the allegedly won ELO points and the next game in the tournament.

Moreover, it is dangerous to trust the evaluation of chess engines. A position which an engine assesses as 0.00 is not necessarily an easy draw for both sides.

Top 5 Best Chess Engines Of The World In 2018
This position is a fortress. Still, until recently, many chess engines evaluated it wrongly.

It can also mean that one side has to eliminate the opponent’s strong initiative with 10 precise moves in a row. Practically speaking, this is an extremely difficult task.

Hence, it is important to understand why computers give certain evaluations. It should also be noted that chess engines are not able to detect fortresses.

You can take a look at the position on the right. Black managed to create a fortress. He can just move his rook between f6 and d6. If White gives checks with his queen, Black’s king always stays next to the pawn.

White can’t make any progress.

One of the biggest criticisms of chess engines in the past was their inability to accurately evaluate such fortresses.

Such a position might well have received a +2.00 evaluation not very long ago. However, thanks to the continuing advancements in chess engines, Stockfish 13 now rates this position even no matter which side is to move.

There Is No Substitute For Putting in the Hard Work

The right tool for the right job is a wise saying we would do well to heed even in our technological age. Chess engines are a great aide to chess players, especially if you train alone.

However, legitimate chess improvement requires a level of discipline that prefers to avoid shortcuts and opts for the steeper path to real knowledge and understanding.

More and more chess players become too lazy to think on their own. Instead, they almost always look at the engine’s evaluation.

This superficial approach to chess study will not only fail to improve your chess game, but it will also make you worse by enforcing bad habits.

Chess games among human beings involve a lot more subtleties than a simple computer evaluation like +0.51 can tell you.

Conclusion – Best Chess Engines

There are other powerful chess engines out there. I don’t think anybody can argue against Alpha Zero being the top dog. However, Alpha Zero is not available to the public.

Stoofvlees is another strong chess engine, but it is unavailable too.

The impact of Alpha Zero on the development of chess engines also can’t be denied. Many of the top chess engines now include NNUE as a result of playing against Alpha Zero.

Chess engines are a curse and a blessing at the same time. Chess players who use them intelligently greatly benefit from the rise of strong computers.

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18 comments on “Top 6 Best Chess Engines in the World in 2021

  1. Chris Ferrante says:

    As the fortress position has only five pieces (where pawns are considered pieces), a tablebase with this position has been available for many years. Any chess engine that utilizes tablebases would instantly evaluate the position to a draw because it only needs to check the tablebase. No analysis is required.

  2. MARK GITTENS says:

    A lot of nonsense is spoken about computer chess engines. I am confident that the very best human chess players would never beat Stockfish 14 set at maximum strength. To claim otherwise is disingenuous. A novice chess player using stockfish 14 can easily draw or beat the best human players who are not using chess engines. Why pretend otherwise?

  3. Chess Engine List says:

    Well, this ranking list should not evolve Houdini 6. This rating is according to CCRL Classical Rating List. Houdini 6 is outdated, even Leela, Nemorino, SlowChess, Fire are better than Houdini. Next, some comments says AlphaZero is better than Stockfish, AlphaZero is better than Stockfish 8, Not stockfish 13, SF 13 is better than AlphaZero about +250 elo. FF2 is just completely Stockfish, is just a clone, but is a worst version, don’t pay 100 euro for this garbage.

  4. Robert Pemberton says:

    A few issues here:
    All of the chess engines need to move down a rank. Alpha Zero is stronger that Stockfish and it isn’t even mentioned in the list.

    Secondly, that fortress position is evaluated exactly at 0.0 and 0.0 for black or white to make the first move on stock fish. The engine understands it completely.

    There is nothing wrong with learning from chess engines. It’s easy to get into a habit of playing bad moves because they’re comfortable and chess engines can help you get out of the bad habits.

    When you need to go for the easy queen capture or 8 move check mate the solution isn’t to always go for the queen. It depends on how much time you have, how well you can see the 8 moves, and how tired you are. If you can see the 8 moves clear as day, go for it – if not the queen capture will most likely lead to victory, but not necessarily.

  5. Christopher Dube says:

    Since, I am perhaps a C level player (around 1750), I still have an outdated version of Chessmaster.

    I know it’s not a top level program by any stretch, but the program comes equipped with about 250 separate “personalities.” I play rated games against them and then have Chessmaster analyzed the games.

    Still, it plays around 2700, so it’s quite strong. I find it helpful.

  6. AlphaZero can beat or draw any chess GM every time.
    It was able to do so after only 4 hours of running.
    It is based on deep learning algorithms that do not require any libraries or influence, just computer power * computing time.
    If you gave it exactly 0 seconds to think, then of course it would not beat GMs. It would not make moves.
    The point is that in under an afternoon it has had enough time to think to beat all the GMs.
    Give it more time and the question isn’t even interesting.

  7. Chris Dube says:

    Im not convinced the best GM cannot beat these programs.

    The computer’s advantage is 3 fold. First, they never forget. Second, they play with no emotions. Finally, because they can make virtually limitless calculations very quickly.

    That being said, if you forced the computers to play say Chess 960, (the pieces are rearranged so their library is useless). Let’s see how good they are when they have to rely on instincts and chess principles.

    It’s why Kasparov was so angry when GM Joel Benjamin inserted Kasparov’s win against Deep Blue into its memory bank during the match.

  8. Rahul says:

    I think computer engines have been built using experience of Chess masters and hence years of experience cannot be out classed just by a novice user. This might just the biggest block in a person’s interest in trying to do something new with those chess pieces.

  9. Northern says:

    Actually, the new strongest engine although it’s not for sale, is AlphaZero.

  10. Dara says:

    Sure, but alpha zero cannot be downloaded 🙁

  11. Gabriel says:

    Alpha zero from Google beats all of these ai

  12. ayush gupta says:

    please tell mei how to learn from computers??thanks

    1. Uwe says:

      I think best is to analyse your own games with a computer.

    2. iChess Contributor says:

      You can learn from computers by using them like a chess coach. Ask the computer questions! Think on your own first in any position and consider the moves and variations you’d like to play. You can then recheck your analysis with the help of the computer. If you like a move and the computer doesn’t show it, enter the move and check why the computer doesn’t like the move.
      On top of that, computers also help you to detect many hidden tactical resources in your games which you most probably don’t find on your own. In any event, it’s key to use computers only in combination with your own brain. Try to study chess as actively as possible – even when analyzing with an engine.

    3. Bent Hansen says:

      learning from a chess computer/program.
      Take a random opening and study. eks. 1.e4 – e5.2.Nf3 – Nc6.3.d4 – exd4.4.Bc4 – Bc5. ( A well know´n opening ) but sins wee are trying to use a program/computer, lets have a bit of “fun” and play 5.c3 – dxc3, and now 6.Bxf7+….. this position is full of possible traps, and here a program will help you understand what to look for. Also if you like to study your own game or maybe study games from stronger players, here, find a position that you may like to understand better, or just try to see, how it can be play better ( sins most programs are stronger then most players, ) som chess programs ( like the Chess master 10 ) also have teaching games, where som GM have analyst som games, and in that, giving you a understanding on what is going on in the game.
      I wich you good luck wth your study

  13. ayush gupta says:

    thanks alot sir thi article deals with the many interesting facts and topics abuout engine i am sure that any of the chess players can learn a lot about that and elimainate the bad habits that is because of enginges thanks alot sir yo uare the bst

    1. iChess Contributor says:

      Thanks a lot!

    2. joe says:

      haha you must be a computer programme with a few bugs in it

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