New Chess Engine Versions: Lc0 0.31.2, CorChess 4.5, & More on Chessify

We're excited to announce that several of our supported engines have just received important version updates on Chessify! Earlier this year, we updated Stockfish to its 17.1 version, and now almost all the remaining engines have caught up with fresh upgrades. Let’s go through the updates so you can pick the ones best suited to your chess goals.

Here’s what’s new:

Lc0 0.31.2

The latest version of Leela Chess Zero brings improved evaluation consistency and accuracy. As one of the top neural network engines, it excels in positional understanding and is loved by professionals for its human-like decision-making style.

CorChess 4.5 dev-20250513-847f4ccc

Built on top of Stockfish, CorChess continues to evolve alongside it and remains in high demand among correspondence chess players for its deep search capabilities and evaluation precision.

Caissa 1.22

A lightweight yet surprisingly strong engine, Caissa continues to improve its analysis quality. It's ranked among the top 10 highest-rated engines in the CCRL 40/15 list, making it a reliable option for fast and sharp evaluations.

Crystal 9

A Stockfish derivative known for its ability to detect fortresses in endgames, Crystal 9 has been updated with upstream Stockfish improvements. This version includes several code cleanups and optimizations that enhance its stability and speed.

Patricia 4

Patricia 4 is out with major upgrades: a new neural network trained on Patricia data, improved search patches, and a rewritten bitboard. She remains the most aggressive engine in our lineup while closing the gap on top performers in terms of strength.

Viridithas 18.0.0-dev

Though still in dev stage, this version of Viridithas brings notable enhancements in complex positions. As one of the newer engines on Chessify, it keeps rising in strength and originality with every update.

Koivisto 9.2

First released in 2020, Koivisto now comes in its 9.2 version, offering faster evaluations and a refined neural network trained on billions of chess positions. A solid blend of traditional search and NN evaluation.

RubiChess 20250505

Once a private hobby project, Rubichess is now competing against the strongest chess engines in the world and has a 3600+ rating. The latest update is now available on our analysis dashboard as well.

ShashChess 38

ShashChess 38 introduces a key architectural upgrade by isolating its Shashin framework—an advanced positional zone management system—into a dedicated module, improving modularity and scalability. Combined with its WDL model and strategic evaluation zones, the engine continues to offer a uniquely human-like approach to handling complex positions.

Cloud Server Speed Options for the New Chess Engines

All engines (except for Lc0) are available for free at 1 MN/s (1000 kN/s) on Chessify’s Analysis Dashboard. For those seeking faster analysis, we offer powerful cloud servers with speeds up to 130 MN/s.

Here’s how the server speeds map to plans:

• - 1 MN/s – Free
• - 10 MN/s – Amateur Plan ($7.99/month or $79.99/year)
• - 20–100 MN/s – Master Plan ($34.99/month or $349.99/year) and GM Plan ($1200/year)
• - 130 MN/s – Dedicated Server (10 coins/minute via Chessify Coins)

Note: The performance of each engine may vary depending on the position analyzed.

All engines are available to use immediately in Chessify’s cloud analysis platform without registration. With a free account, you can use Chessify's 1 MN/s free server to analyze with all of these engines except for Lc0, which is available via coins or as part of the GM plan.

You can find our detailed pricing and subscription options on our Pricing Page.

How to Analyze with Lc0, CorChess, Caissa, and other Engines Online

You can start using the updated chess engines by visiting chessify.me/analysis. No registration is required to try CorChess, Caissa, Crystal, Viridithas, and several other engines at 1 MN/s for free. However, if you want to use Lc0 0.31.2, you will need to have either coins or the GM subscription plan.

For newcomers, we offer helpful video tutorials to get you started. Watch below and dive into cloud-based chess analysis with confidence.

As always, we’ll keep bringing the strongest tools to your fingertips. Let us know what engine you’re excited to try next or tag us with your findings!