OpeningNinja
How it works

From PGN to mastered repertoire

OpeningNinja turns the openings you already study into focused, trackable practice — in six simple steps.

  1. 1

    Upload your PGN

    Bring your repertoire as a PGN file and pick the side you want to train — White or Black. OpeningNinja reads every move and variation and turns it into a set of trainable lines. Nothing to set up, no account required.

  2. 2

    Resolve ambiguities

    Wherever your side has more than one move in the PGN, OpeningNinja can't know which you actually intend to play — so it asks. The "Choose Your Move" step walks you through each fork and you pick your line. Your opponent's alternatives are kept, each becoming a separate line to train against.

  3. 3

    Train your lines

    Drill your repertoire in three modes: Random to test true recall, Structured to learn systematically, and Priority to hit unseen and weak lines first. Turn on Perfect Mode to restart a line the moment you slip — ideal for building real muscle memory.

  4. 4

    Track your progress

    Every session is recorded. Watch your accuracy climb, see how many lines you've mastered, spot the exact positions where you keep going wrong, and keep your training streak alive.

  5. 5

    Update, don’t edit

    OpeningNinja deliberately doesn't let you edit lines in the app — your PGN stays the single source of truth. Tweak it in whatever tool you like, hit Update PGN, and OpeningNinja re-parses it and detects any new lines automatically. (Re-importing resets training progress for that opening.)

  6. 6

    Share & export

    Share an opening with a link — anyone you send it to can clone it straight into their own account (links last 7 days). Or download any opening back to PGN any time, for backups or to use in other chess software.

Free, and no account needed

Everything above works completely free, offline, without signing in. Your repertoire and progress live on your device. The only thing behind a subscription is optional cloud sync — so you can back up your data and pick up training on any device.

Ready to try it?

Import your first PGN and start training in under a minute.

Upload PGN