Theoria
New Theoria 3.0, now in your browser

The learning tool for chess openings.

Every line you play as one tree, built from your games and trained with spaced repetition.

Chess.com or Lichess. No sign-up: we only read your public games.

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Download on theApp Store Get it onGoogle Play
How it works

From the games you play to moves you know cold.

  1. Start from your games

    Give Theoria your Lichess or Chess.com username and it builds a repertoire from the moves you actually play, with every common reply covered. Or begin from a curated repertoire, a Lichess study or a PGN.

  2. See the whole plan

    Your openings become one map, the start position at its centre and each ring a move deeper. Zoom out to see the shape of everything you play; zoom in and every dot is a board you can play on.

  3. Train it until it sticks

    Theoria plays your opponent's moves and you find yours. Each position returns just before you'd forget it, misses come back before the session ends, and mastery fills in across the map as you learn.

Features

Find the holes before your opponents do.

Explorer and engine

See what's played most in every position and how it scores, from millions of Lichess games, with Stockfish running right on your device.

Your win rates

Colour the map by how each line scores in your own games, or by engine evaluation, and the lines that cost you points stand out at a glance.

Optimize

One tap finds the popular replies you haven't prepared, the positions where you've planned two moves, and the moves the engine doesn't trust. Another fixes them.

Levels and quests

Earn XP for every move you get right, climb from Bronze to Grandmaster, and keep a daily streak going with three fresh quests each day.

Game review

Step through any of your games and see the exact move where it left your repertoire, and whether you or your opponent strayed first.

Endgame lessons

The essential endgames, from the Lucena to bishop-and-knight mate. Learn each with a guided lesson, then play it out against Stockfish.

Web, iOS and Android

Prepare on your laptop. Drill on your phone.

Theoria runs in your browser, on iPhone, iPad and Android. Sign in once with Lichess, Google or Apple, and your repertoires, streaks and progress follow you from one to the next.

Open it in yourBrowser Download on theApp Store Get it onGoogle Play
Theoria on three phones: a position with its move statistics, the repertoire graph, and a training session asking which move you play
Openings encyclopedia

Explore over 3,000 chess openings.

Every named opening and variation, with how often it's played, how it scores and the moves that come next. Find a line you like, then make it yours.

Browse all openings

From our players

Organized knowledge wins games.

“The real value of Theoria is in the organization of knowledge. Between courses, books, and videos, I was learning about openings but struggled to remember the moves in practice. Having a cohesive plan makes all the difference!”
Hannah, beta tester
“I was stuck around 1000, and figured it was finally time to learn some openings. I love how I can choose every move, so I can express my unique style and play to my strengths.”
David, beta tester
“Theoria has revolutionized the process of developing an effective repertoire.”
Alex, chess coach
“A joy to use. Learning openings has never been so simple.”
Mike, beta tester
Pricing

Free for good. Pro when you go deeper.

Free

Free forever, no ads

  • 2 repertoires of up to 300 positions
  • Import from Lichess and Chess.com
  • Spaced repetition training
  • Engine, game review and win rates
  • Curated repertoires and the basic endgames
  • Web, iOS and Android

Theoria Pro

Monthly, yearly or for life

  • 12 repertoires of up to 3,000 positions
  • Lines up to 100 moves deep
  • The full opening explorer
  • Every endgame
  • Extra daily quests, and re-rolls
  • Everything in Free

Frequently asked questions

Is Theoria really free?

Yes, and without ads. The free plan covers everything you need to build and train a repertoire: two repertoires of up to 300 positions, import from your games, spaced repetition, the engine and game review. Theoria Pro, monthly, yearly or for life, is for when you outgrow it.

Can I use Theoria in my browser?

Yes. The web app is the full Theoria, not a lighter version. Sign in with Lichess, Google or Apple and your repertoires and progress follow you between web, iOS and Android.

Can I start from the openings I already play?

That's the best way to begin. Enter your Lichess or Chess.com username and Theoria builds a repertoire from the moves you play most, with every common reply covered. It even sets each move's starting mastery by how consistently you play it, so training starts where you are. A PGN or a Lichess study works too.

What if I don't know any openings yet?

Start with a curated repertoire. Theoria offers expert-designed repertoires for every playstyle, with notes that explain the ideas behind the moves. Install one with a tap and start training straight away.

How is Theoria different from an opening course or book?

Courses and books teach you lines. Theoria helps you choose yours, see how they fit together, and remember them at the board. It doesn't tell you what to play: use it alongside whatever you study and keep your whole plan in one place.

What is spaced repetition?

A way of reviewing each move just before you would forget it. Answer quickly and correctly and a move comes back later; miss it and it comes back sooner. Your time goes to the moves that need it, not the ones you already know.

Your repertoire, finally in one place.

Free, without ads, and ready in your browser in seconds.

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