Chess engines have revolutionized the way we understand and play chess.
With their vast knowledge and computational abilities, they provide deep insights into chess strategy and tactics.
This article highlights the most powerful chess engines in the world, particularly focusing on two giants of the field: Stockfish and AlphaZero.
Best & Most Powerful Chess Engines
There are several powerful chess engines available today, and the “best” one can depend on various factors such as hardware, time controls, and personal preferences.
However, here are some of the top chess engines known for their strength and performance:
Stockfish
Stockfish is one of the strongest and widely used chess engines.
It is an open-source engine that consistently performs at the highest level in computer chess tournaments.
Stockfish has a powerful search algorithm and an extensive evaluation function, making it a formidable opponent.
AlphaZero
AlphaZero is a revolutionary chess engine developed by DeepMind, the same team that created AlphaGo.
Unlike traditional engines, AlphaZero is self-taught and learned the game of chess solely through reinforcement learning.
It demonstrated extraordinary performance by defeating Stockfish convincingly in a 100-game match.
Komodo
Komodo is another highly regarded chess engine known for its strength. It has achieved excellent results in various computer chess championships.
Komodo is known for its positional understanding and strategic play, making it a challenging opponent for players of all levels.
Leela Chess Zero (LCZero)
LCZero is an open-source chess engine based on the AlphaZero concept.
It also uses deep neural networks and reinforcement learning techniques to improve its play.
LCZero has shown impressive strength and has gained a large following in the chess community.
Houdini
Houdini is a commercial chess engine known for its strong tactical play and calculation abilities.
It has been among the top-ranked engines in various computer chess championships.
Houdini combines positional understanding with tactical prowess to deliver a formidable playing style.
It’s important to note that the strength of chess engines can improve over time due to ongoing development and optimization.
Different engines may perform better in specific areas or be better suited for certain hardware configurations.
Therefore, it’s always a good idea to experiment and find the engine that suits your playing style and requirements.
Torch
Torch is a new chess engine developed by Chess.com.
It’s built from the ground up by a team of top chess engine developers, including Andrew Grant (Ethereal), Finn Eggers & Kim Kåhre (Koivisto), Jay Honnold (Berserk), and Michael Whiteley & Dietrich Kappe (Dragon). Mark Lefler and Larry Kaufman have been advisors to the project.
Torch is currently the second-strongest chess engine in the world, according to the Computer Chess Rating List.
It has performed very well in competitions, including winning the Chess.com Computer Chess Championship.
Torch uses a variety of techniques to evaluate positions and make moves, including:
- Monte Carlo tree search (MCTS): MCTS is a search algorithm that uses random sampling to explore the search tree. This allows Torch to find good moves in positions where traditional search algorithms would be too slow.
- Neural networks: Torch uses neural networks to evaluate positions and predict the moves of its opponent. This allows Torch to make better decisions in complex positions.
Torch is still under development, but the team behind it is committed to making it the strongest chess engine in the world. They are constantly working on new features and improvements.
Torch is not yet publicly available, but Chess.com has announced that it will be made available to certain relevant third parties for ratings in the future.
It will also be available through Chess.com’s analysis in the future.
The Strongest Computer Chess Engines Over Time
Let’s look at each in a little bit more detail.
Stockfish
Stockfish is one of the strongest chess engines available.
It’s an open-source UCI (Universal Chess Interface) engine, available for various platforms.
Stockfish has an extremely high ELO rating, often exceeding 3500. Unlike many other chess engines, Stockfish does not use endgame tablebases, instead relying on its own algorithms to navigate endgame positions.
Stockfish 15 & 16
The latest versions, Stockfish 15 and 16 offer several enhancements over its predecessors, improving both its evaluation function and search algorithms.
The developers behind Stockfish have continuously tweaked and improved it over time, ensuring it remains at the forefront of computer chess.
The latest version is even stronger and faster, consolidating its position as one of the strongest chess engines ever.
Stockfish Chess Strengths
Stockfish excels in various areas, including analytical strength, understanding positional nuances, exploiting small advantages, and conducting deep searches.
It offers multiple configuration options, allowing users to adjust the engine to their preferences.
With its potent capabilities, Stockfish is often the engine of choice for serious chess analysis and preparation.
Free Chess Engine
Stockfish stands out not only for its powerful computing capabilities but also because it’s free.
Being open-source software, any developer or interested party can contribute to its enhancement, or study the code for educational purposes.
The fact that such a high-quality chess engine is available for free to everyone is a testament to the dedication and commitment of the global chess community.
AlphaZero Chess Engine
AlphaZero is a game-changing AI developed by DeepMind, a subsidiary of Alphabet Inc. (Google)
Unlike traditional chess engines, AlphaZero uses a different approach, utilizing machine learning and neural networks.
It taught itself chess from scratch, using no opening libraries or endgame tablebases.
After just a few hours of self-play, AlphaZero reached a level of strength that surpassed all other chess engines.
It is popular for sacrificing material and pushing pawns higher up the board on the flanks.
AlphaZero vs. Stockfish
In a series of matches held in 2017 and 2018, now in the old ages of chess AI, AlphaZero demonstrated its superior capabilities by convincingly defeating Stockfish.
The matches were groundbreaking and changed our understanding of chess played at the highest level.
AlphaZero showed a style of play that was both aggressive and intuitive, often favoring piece activity and dynamic considerations over material.
It demonstrated a deep understanding of chess that was hitherto unseen in engine play.
Stockfish vs. Leela
Stockfish and Leela are both powerful chess engines, but they operate on fundamentally different principles:
Architecture
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- Leela: Leela is built on a neural network, which is a type of machine learning model designed to recognize patterns and make decisions based on those patterns. This makes it computationally expensive to run.
- Stockfish: Stockfish, on the other hand, is a traditional alpha-beta search engine. It doesn’t rely on machine learning but uses handcrafted evaluation functions and deep search to evaluate positions.
Depth of Analysis
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- Stockfish: Stockfish’s strength lies in its ability to analyze positions deeply, often looking 20 to 30 moves ahead, and even more during endgames. This deep search allows it to find tactical opportunities that might be missed by shallower analyses.
- Leela: While Leela operates at a much lower depth compared to Stockfish, it compensates with a superior understanding of individual positions. This understanding allows Leela to sometimes “see” further into a position than Stockfish, even if Stockfish is technically analyzing more moves ahead.
Positional Understanding
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- Stockfish: While Stockfish can look many moves ahead, it sacrifices a bit of positional understanding to achieve this depth. It focuses on raw calculation power.
- Leela: Leela’s strength is its ability to understand individual positions deeply. This can sometimes allow it to recognize tactics or strategies that Stockfish might miss, especially if those tactics are beyond the depth that Stockfish is analyzing.
Cost and Efficiency
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- Leela: Due to its reliance on a neural network, Leela is more computationally expensive to run. However, this investment allows it to have a deeper understanding of individual positions.
- Stockfish: Stockfish is more efficient in terms of computational resources. It can analyze positions deeply without the same computational cost as Leela.
While both Stockfish and Leela are top-tier chess engines, they offer different strengths.
Stockfish excels in deep tactical analysis, while Leela shines in its profound positional understanding.
Depending on the position and the depth of the tactic, one might outperform the other.
It’s this combination of deep search and positional understanding that makes the world of computer chess so fascinating.
Leela has also been known to beat Stockfish occasionally playing black (i.e., beating Stockfish when it plays white).
We have that game in the article below, where Leela won with a queen and bishop checkmate in 115 moves.
Related: Stockfish vs. Leela
Is AlphaZero the Best Chess Engine?
Given its performance against Stockfish, many consider AlphaZero to be the best chess engine.
Its unique self-learning approach allows it to understand and create novel strategies, which has redefined computer chess.
However, it’s worth noting that AlphaZero is not publicly available (Leela is the publicly available version, mentioned below), unlike Stockfish.
While Stockfish and Alphazero are 1a and 1b (take your pick), some other strong chess engines are worthy of mention:
Leela Chess Zero (LCZero)
Leela Chess Zero, often abbreviated as LCZero, is a unique chess engine that employs a deep neural network-based approach for playing chess.
Unlike traditional engines that rely on a set of predefined rules and evaluations, LCZero learns to play chess through a process known as self-play reinforcement learning.
LCZero’s training involves running millions of games against itself, allowing it to learn and improve its play over time.
It utilizes deep convolutional neural networks to evaluate positions and make move predictions.
This approach enables LCZero to have a more human-like playing style and to come up with creative and unconventional moves that may not be immediately apparent to traditional engines.
LCZero gained attention in the chess community due to its strong performance and unique learning methodology.
It has achieved remarkable results, challenging and defeating some of the strongest traditional chess engines in various competitions.
Komodo
Komodo is a powerful chess engine that has been developed by a team of programmers, including chess grandmaster Larry Kaufman and computer scientist Mark Lefler.
It is known for its strong positional understanding and strategic play.
Komodo has achieved remarkable success in computer chess competitions and is considered one of the top chess engines in the world.
Komodo utilizes advanced search algorithms, evaluation functions, and heuristics to analyze millions of positions per second and make highly optimized moves.
It employs a combination of brute-force calculation and selective search techniques to explore the chess tree and determine the best move in a given position.
Komodo also incorporates various sophisticated techniques such as advanced pruning, parallel processing, and endgame tablebases to enhance its performance.
Houdini
Houdini is a renowned chess engine developed by Belgian programmer Robert Houdart.
It is known for its exceptional tactical play and precise calculation abilities.
Houdini has consistently been one of the top-ranked engines in computer chess tournaments and has a strong reputation for its strong positional understanding and resourceful defense.
Houdini incorporates advanced algorithms, including alpha-beta pruning, null-move heuristics, and sophisticated evaluation functions, to explore the search space efficiently and make optimal moves.
It also makes use of powerful endgame tablebases to play endgame positions flawlessly.
Houdini’s strength lies in its tactical awareness and ability to calculate deep variations accurately.
It excels in complex positions, where it can identify subtle tactics and combinations.
Houdini has been a popular choice for both professional chess players and chess enthusiasts looking for a strong and reliable analysis tool.
Overall, these three secondary chess engines, Komodo, Leela Chess Zero, and Houdini, represent different approaches to computer chess and have achieved remarkable success in their respective domains.
- Komodo combines strong positional play with advanced search techniques
- LCZero employs deep neural networks for a more human-like playstyle, and
- Houdini specializes in tactical prowess and precise calculation
Most Powerful Chess Engine in the World
Determining the most powerful chess engine can be somewhat subjective, as it depends on what one values in an engine.
In terms of sheer strength and public accessibility, Stockfish is currently the reigning champion.
However, if we consider innovative approaches and capabilities to generate novel strategies, AlphaZero arguably takes the lead.
Strongest Chess Engine Ever
AlphaZero, with its self-learning capabilities and dynamic style of play, has shown that it can compete with and even outperform traditional chess engines like Stockfish.
However, since it’s not publicly available, Stockfish remains the most powerful accessible chess engine.
What Are the Best Chess Engines?
Beyond Stockfish and AlphaZero, several other chess engines are highly rated.
These include Leela Chess Zero (LCZero), an open-source project inspired by AlphaZero’s success, and Komodo, another top-tier traditional chess engine.
Both offer impressive capabilities and have high ELO ratings.
Strongest Mobile Chess Engine
On the mobile front, Stockfish also holds its ground.
The mobile version maintains a high level of play, making it the strongest mobile chess engine available.
Other noteworthy engines include the mobile versions of Komodo and the Shredder Chess engine.
What is the Strongest Chess Engine in the World?
As of 2025, the strongest publicly available chess engine is Stockfish 16.
It delivers top-tier performance on both desktop and mobile platforms.
However, the AI-developed AlphaZero, though not publicly accessible, has demonstrated extraordinary capabilities, leading many to consider it the overall most powerful chess engine.
Leela is based on the AlphaZero concept and is in the same league as Stockfish.
