Houdini Chess Engine
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HOUDINI 4 has been released - Get it Today!

Welcome to the Houdini Chess Engine home page. Houdini is a state-of-the-art chess engine for Windows combining outstanding positional evaluation with the most sophisticated search algorithm.

The name Houdini was chosen because of the engine's positional style, its tenacity in difficult positions and its ability to defend stubbornly and escape with a draw – sometimes by the narrowest of margins. On the other hand Houdini will often use razor-sharp tactics to deny its opponents escape routes when it has the better position.

At the time of writing Houdini leads all the major Computer Chess rating lists and is widely considered to be the strongest chess engine on the planet. From numerous interviews it appears that many top Grand Masters and World Champions use and appreciate Houdini.

The Chess Club Live Facebook page phrased it like this: "If there ever was a computer descendant of the romantic players like Morphy, Anderssen, Spielmann, Marshall, Bogoljubow, Tal, Nezhmetdinov, Shirov, Morozevich it would be Houdini. Houdini is the current World number 1 chess engine and plays in a very romantic style."

Get the new Houdini 4 today!

Follow the development of the Houdini Chess Engine on Facebook:

Houdini 4: The Best Got Even Better!

The new Houdini 4 contains many evaluation and search improvements in all phases of the game and is about 50 Elo stronger than its predecessor. The improved strength means that Houdini 4 nearly doubles the chess performance of your PC for game analysis and match play.

A major feature is the support of the new 6-men Syzygy table bases. Houdini 4 has been extensively tuned for this state-of-the-art end game table base system and will provide optimum precision and strength in the late endgame at any time control and with any number of cores. While we strongly recommend using the 6-men Syzygy tables, Houdini 4 continues to support Nalimov and Gaviota table bases.

Houdini 4 maintains and improves on all the goodies that made previous Houdini versions the preferred analysis tool for many chess players. The Tactical Mode of Houdini 4 will find more solutions and provide faster solution times in tactical test suites than any other engine. Persistent Hash and Learning are essential tools for storing your valuable analysis results for future use. Houdini's very efficient multi-PV analysis and its support for Chess960 a.k.a. Fischer Random Chess remain the reference in the industry.

Houdini 4 uses calibrated evaluations in which engine scores correlate directly with the win expectancy in the position. A +1.00 pawn advantage gives a 80% chance of winning the game against an equal opponent at blitz time control. At +2.00 the engine will win 95% of the time, and at +3.00 about 99% of the time. If the advantage is +0.50, expect to win nearly 50% of the time.

The on-line Houdini Chess Engine User's Manual provides clear and detailed instructions so that you can effortlessly leverage your chess analysis capabilities.

Houdini 4 Download Versions for Windows

Houdini is written for Windows and will run on any not too ancient Windows version. On Linux systems you can run Houdini using Wine without any significant performance loss. On Apple computers a Virtual Machine (e.g. Parallels Desktop) is required to run Houdini.

Two Houdini 4 download-only versions are available:
Houdini 4 Standard
€39.95 +VAT*
Best buy for most users with main-stream hardware.
Supports up to 6 cores and 4 GB of hash.
Houdini 4 Pro
€59.95 +VAT*
For high-end users with powerful hardware. Supports up to 32 cores and 256 GB of hash memory and NUMA-architecture. Click here for more information about Houdini Pro.
*21% VAT will be added for customers from EU member states.

The Houdini 4 download link and serial number will be sent to you by e-mail within 24 hours of purchase. Note that during installation you'll require an internet access to activate the product.

If you haven't received our purchase confirmation mail within 24 hours, check your spam folder first, and if the mail is not there please contact us immediately via the support e-mail address [email protected].

Purchasing Houdini 4 will entitle you to all updates and corrections made to Houdini 4, direct e-mail support by the Houdini author and discounts to future versions of Houdini.

Too expensive? You can still download the free Houdini 1.5 which at the time of the Houdini 4 release remains one of the top chess engines.


Direct support by the author of Houdini, Robert Houdart, is available by e-mail at the address [email protected].

Before mailing please check out the on-line Houdini Chess Engine User's Manual with installation tips and Frequently Asked Questions.
If for whatever reason e-mail communication fails, you can contact us via the Houdini Facebook page.

Version History

Houdini 4

  • Houdini 4 (20131125): Major new version. Improved search and evaluation (+50 Elo), 6-men Syzygy table bases.

Houdini 3

  • Houdini 3 (20121015): Major new version. Improved search and evaluation (+50 Elo), Tactical Mode, Scorpio bitbases.

Houdini 2

  • Houdini 2.0c (20111120): Maintenance update with minor bug corrections and new analysis options.
  • Houdini 2.0b (20111007): Maintenance update with minor bug corrections and Nalimov EGTB support.
  • Houdini 2.00 (20110901): Improved analysis capabilities, enhanced search and evaluation.

Houdini 1.5

  • Houdini 1.5a (20110115): Maintenance update with work-arounds for Fritz GUI and other minor improvements.
  • Houdini 1.50 (20101215): Improved search and evaluation. Gaviota Table Base Support.

Houdini 1.0

  • Houdini 1.03a (20100717): Bug fix for Multi-PV.
  • Houdini 1.03 (20100715): Multi-PV, searchmove and large page support. Improved evaluation function.
  • Houdini 1.02 (20100618): SMP and hash collision bug fixes. Work-around for Shredder GUI.
  • Houdini 1.01 (20100601): Bug fixes. Improved search algorithm.
  • Houdini 1.00 (20100515): First release.


An invaluable resource for any chess engine author is the excellent Chess Programming Wiki.

Without many ideas and techniques from the open source chess engines Ippolit and Stockfish, Houdini would not nearly be as strong as it is now.

The Gaviota EGTB probing code used by Houdini is © Miguel A. Ballicora, the Nalimov EGTB probing code is © Eugene Nalimov and the Syzygy TB probing code is © Ronald de Man.

The Houdini development was greatly aided by the kind support of Mr. Ahmed Mansoor.