High-strength local engine analysis
- Professional-grade Stockfish 19 calculation
- Adjustable engine time — 0.25 s, 1 s or 3 s per position
- No separate engine installation required
- Fast response without depending on a remote analysis engine
POWERED BY STOCKFISH 19
Powerful Stockfish 19 analysis for Chess.com.
Fast local engine calculation.
Built specifically for Chess.com.
Private by design.
- Stockfish 19
- Built for Chess.com
- 250 free moves
- Local engine
- Privacy first
The Chrome Web Store release is pending approval. When the listing is live this button opens it; the extension is an independent third-party product.
Chrome Web Store release pending approval. Chess Assistant is an independent third-party product and is not affiliated with or endorsed by Chess.com or the Stockfish project.
The engine
Powered by Stockfish 19
Chess Assistant ships a copy of the Stockfish 19 engine inside the extension, so the analysis runs on your own computer. There is no remote analysis service and no separate engine to install.
Built specifically for Chess.com
- Designed and tested for Chess.com boards
- Reads the position from the board you have open
- Compact browser panel beside the board — no second window
- Chess.com only: other sites are not supported
Compatibility
Built for Chess.com, and honest about the rest
Chess Assistant is deliberately narrow: one site, supported properly.
Currently supported
- Chess.com
The extension runs only on https://www.chess.com/* and https://chess.com/*.
Not currently supported
- Lichess
- Other chess websites
- Desktop chess applications
- Arbitrary web chess boards
This is not a universal chess assistant and it makes no claim to work anywhere else.
Features
What Chess Assistant does
Everything below is in the extension today. Nothing here is a roadmap item.
Stockfish 19 local analysis
A full engine session runs on your computer and reports the best line it finds.
Automatic board detection
The panel finds the Chess.com board that is currently visible and follows you when you navigate.
Position and FEN recognition
The board position is read from the page and handed to the engine — no manual FEN pasting.
Strong candidate move calculation
The engine's principal line and evaluation are shown for the position on the board.
Adjustable engine time
Choose 0.25 s, 1 s or 3 s per position to trade speed for depth.
Adjustable move delay
A 0–10 second delay between assistant moves, so you control the pace.
White / Black side selection
Tell the assistant which colour you are playing and it works on that side.
Assistant move controls
A single Make move action plays the engine's move on the board; Stop ends everything instantly.
Autoplay controls
Let the assistant continue move by move, with the delay and engine time you chose.
Persistent account login
Your session is remembered between tabs and browser restarts on the same device.
Free and Pro accounts
A free account starts with 250 assistant moves; Pro removes the limit.
Secure subscription management
Upgrades and cancellations run through Stripe's own pages and customer portal.
Pricing
Simple pricing
Start free. Upgrade only if you want unlimited assistant moves. No countdowns, no fake discounts.
Free
€0
- 250 assistant moves per account
- Stockfish 19 analysis
- Local engine calculation
- Chess.com integration
- No payment card required to start
Create an account in the panel and start analysing.
Most complete
Pro
€4.99/ month
- Unlimited assistant moves
- Stockfish 19 analysis
- Local engine calculation
- Chess.com integration
- Secure Stripe subscription management
- Cancel through the Stripe Customer Portal
Pro is activated inside the extension through Stripe Checkout.
Prices are shown in euros. Pro is a monthly subscription of €4.99 billed through Stripe.
Billing
How billing and cancellation work
Payments
- Chess Assistant Pro costs €4.99 per month.
- Subscriptions are processed securely by Stripe.
- Payment-card details are entered directly into Stripe and are not stored by the Chess Assistant extension.
- The upgrade button inside the extension opens Stripe's own Checkout page.
Cancellation
- Subscriptions can be managed through the Stripe Customer Portal.
- When a subscription is cancelled at the end of the billing period, Pro access remains available until the end of the already-paid period.
- Cancelling stops future billing and changes nothing else about your account.
No refund terms beyond the cancellation described here are published today. For any billing question, contact gratzmvm@gmail.com.
Privacy
Privacy first
The engine work happens on your device. Chess Assistant has no interest in your browsing and no advertising to serve.
No keylogging
The extension installs no keyboard listeners.
No browsing-history tracking
Your browsing history is never read, collected or transmitted.
No advertising SDKs
No ads, no analytics and no tracking scripts are bundled with the extension.
No sale of user data
Your data is never sold or rented.
Your password is never stored
Your Chess Assistant password goes straight to our authentication provider and is not kept by the extension.
Stockfish runs locally
Stockfish analysis runs locally on your device; positions are not uploaded for analysis.
Authentication, subscription status and billing use secure backend services provided through Supabase and Stripe. The Privacy Policy describes exactly what is processed and why.
Responsible use
Chess Assistant is designed for chess analysis, study and training. Users are responsible for complying with the rules of Chess.com and of any competition or game in which they participate.
Do not use external engine assistance where it is prohibited.
Screenshots
The product, as it looks today
Real captures of the extension panel built for Chess.com.
FAQ
Frequently asked questions
What websites does Chess Assistant support?
Currently Chess.com only. Lichess, other chess websites, arbitrary web boards and desktop chess applications are not supported.
Which chess engine does it use?
Stockfish 19, the open-source engine bundled inside the extension.
Does engine analysis run in the cloud?
No. Stockfish analysis runs locally on your device, inside your browser. Account and subscription services use Supabase and Stripe.
Do you store my Chess.com password?
No. Chess Assistant does not request a Chess.com password and never stores one. Your Chess Assistant account password is sent once to our authentication provider and is not kept by the extension.
How does the free version work?
New Chess Assistant accounts receive 250 free assistant moves. You need an account because the allowance follows the account, not the browser.
How much is Pro?
Pro is €4.99 per month and removes the assistant-move limit, so assistant use becomes unlimited.
Who processes payments?
Stripe. Card details are entered on Stripe's own pages and are not stored by the extension.
Can I manage or cancel my subscription?
Yes. Subscriptions are managed through the Stripe Customer Portal, which the extension opens for you.
What happens to Pro when I cancel?
Cancelling stops future billing. When a subscription is cancelled at the end of the billing period, Pro access remains available until the end of the already-paid period.
How do I install it?
The Chrome Web Store release is pending approval. Once the listing is live, this page's button will open it. You can also contact support if you need access sooner.
Is Chess Assistant affiliated with Chess.com or Stockfish?
No. Chess Assistant is an independent third-party product and is not affiliated with or endorsed by Chess.com or the Stockfish project.
Independence and attribution
Who makes this
Independent third-party product
Chess Assistant is an independent third-party product and is not affiliated with or endorsed by Chess.com or the Stockfish project. Chess.com is a trademark of its owner.
Powered by Stockfish 19
Stockfish is an open-source chess engine distributed under the GNU General Public License. It is developed by the Stockfish project and its contributors, not by us, and we make no claim to own it.
Contact
Support
Questions about the extension, your account or a subscription? Email gratzmvm@gmail.com and we will get back to you.
Legal documents: Privacy Policy · Terms of Service