Chess.com vs Local Analysis: What You Actually Get When You Run Stockfish on Your Own Machine

I use Chess.com.

I have an account there. I play games. I like the platform.

But at some point, I started bumping into the same wall.

You finish a game. You want to review it. You click "Game Review." You get a nice breakdown. Accuracy score, move classifications, some engine suggestions.

And then you realize you've used your free review for the day.

That's the thing about Chess.com's analysis. It's good. But it's tied to a subscription model.

I wanted to understand what the actual trade-offs are. So I spent some time comparing what Chess.com's Game Review does versus what happens when you run Stockfish locally.

This isn't a "this is better than that" post. It's just the facts.

Chess.com Game Review: What It Actually Does

Chess.com's Game Review runs Stockfish on their servers. You click a button, their cloud infrastructure evaluates your game, and you get back:

• An accuracy percentage (CAP . Chess.com Accuracy Percentage)
• Move classifications: Brilliant, Great, Best, Excellent, Good, Inaccuracy, Mistake, Blunder
• A centipawn loss graph
• A game report with key moments

It's polished. It's instant. It works in your browser.

The limitation: free accounts get one full Game Review per day.

After that, you get a simplified review with less detail. Or you pay for Diamond.

I'm not saying that's unreasonable. Running engines on cloud servers costs money. But if you play a lot of games. say five or ten in a session. Waiting until tomorrow to review them gets old fast.

What Local Analysis Looks Like

Chess Analyzer Pro does one thing: it runs Stockfish on your computer.

Not on a server. Not in a browser. On your hardware.

Here's what that means in practice:

No limits. You can analyze a hundred games in a row. There's no daily cap because you're not using someone else's compute.

Your data stays local. The PGN files, the analysis results, the database. They live on your machine. Nothing gets uploaded anywhere.

Full control over the engine. You can adjust the number of CPU threads, the hash memory, the analysis depth, and how many alternative lines (Multi-PV) to show. Chess.com's Game Review gives you one view. Local analysis lets you tweak.

But it's not as instant. You need to download Stockfish separately, point the app to it, and configure it. It's not a one-click web experience. It's a desktop application.

The Honest Comparison

Where Chess Analyzer Pro Fits In

Chess Analyzer Pro is a desktop analysis companion. You play your games on whatever platform you prefer, then bring the PGN files here for unlimited local review with Stockfish.

It works alongside Chess.com, Lichess, or any platform that exports PGN. Import via the built-in API connectors, drag and drop a .pgn file, or paste the PGN text directly.

How People Actually Use Both Together

The workflow I see most often:

1. Play games on Chess.com or Lichess.
2. Export the PGN (or use the app's built-in API import).
3. Analyze locally with Chess Analyzer Pro. As many games as you want.
4. Use the local database to track your performance over time.

You get the best of both. The playing experience of the big platforms. The unlimited analysis of a local engine.

The Part That Surprised Me

When I first built this, I assumed accuracy scores would match between Chess.com and the local analysis.

They don't.

Chess.com uses their own CAP formula, which factors in centipawn loss, move consistency, and position complexity in a way they don't fully document publicly.

Chess Analyzer Pro uses a volatility-weighted harmonic mean. Originally inspired by Lichess's approach, but tuned independently. The scores are in a similar range, but they're not identical.

That's fine. They're different tools measuring the same thing in slightly different ways.

Links

• Chess Analyzer Pro GitHub: github.com/imutkarsht/Chess_analyzer
• Download the app: chess-analyzer-ut.vercel.app/releases
• Stockfish Engine: stockfishchess.org/download/