Kingfisher Chess.
Research, in one place.

Opening evidence, engines, databases, studies and repertoire.
Together in one local-first workspace.

Open Kingfisher StudioDownload for macOS
The Kingfisher analysis workspace: the board after 1. e4 e5 2. Nf3 Nc6 3. Bc4 with Stockfish 18 running, its best move drawn as an arrow on the board beside the evaluation bar, the notation and the engine lines in the panel beside it, and the workspace sections — Analysis, Openings, Studies, Repertoire, Preparation, Players, Opening Files, Review, Training, Library — in the sidebarThe Kingfisher analysis workspace: the board after 1. e4 e5 2. Nf3 Nc6 3. Bc4 with Stockfish 18 running, its best move drawn as an arrow on the board beside the evaluation bar, the notation and the engine lines in the panel beside it, and the workspace sections — Analysis, Openings, Studies, Repertoire, Preparation, Players, Opening Files, Review, Training, Library — in the sidebar
206,451Games in the bundled pack
20Full moves indexed
3,810Named openings, ECO codes
0Accounts required · cookies · subscriptions

Why Kingfisher

A workstation, not a wrapper.

Evidence, not a verdict.

Every statistic is labelled with the source it came from. The Explorer never blends Elite OTB with High-Rated Online and prints a single number — you see both, separately, with the licence and provenance on the row.

One board, one tree.

Analysis, Studies, Repertoire, Review, Training and Endgame share a single board and a single move tree. The position you are in is the position the rest of the application follows.

Stays out of the way.

Your work is in the browser. Your reference data is verified against a manifest before the first byte is used. There is no account to set up, no dashboard to learn, no tier to pay for.

Research

Open the line, not just the next move.

A move’s history is the games that played it. The Explorer queries the source you name, returns the count and the trend, and keeps the line, the result, the rating and the licence on the row next to the data — not in a separate document you have to remember to read. Its opening map draws the next three moves at once, each branch as wide as it was played and shaded by how it scored; a click plays the line.

  • Kingfisher StarterBundled · 206,451 games · 300,413 position aggregates · CC BY-SA 4.0 · works offline
  • Elite OTB425,022 games · 5,669,429 positions · CC BY-SA 4.0 · installable on demand
  • Recent Theory44,200 games · 918,069 positions · CC BY-SA 4.0 · two-year window
  • Recent Theory (6 months)11,277 games · 250,498 positions · CC BY-SA 4.0 · rebuilt monthly
  • High-Rated Online305,169 games · 315,668 positions · CC0 1.0 · Lichess 2400+
  • High-Rated Rapid & Classical783,262 games · 735,702 positions · CC0 1.0 · Lichess 2200+, rapid and classical
The Explorer on the Najdorf after 5...a6, comparing the Kingfisher Starter Reference with the Recent Theory Reference: the same candidate moves, each source's own game count and frequency in its own column, and no combined figureThe Explorer on the Najdorf after 5...a6, comparing the Kingfisher Starter Reference with the Recent Theory Reference: the same candidate moves, each source's own game count and frequency in its own column, and no combined figure

Coming from ChessBase?

Bring your databases. Keep your habits.

What you do in ChessBase today, and where it lives in Kingfisher — including what it does not have.

Your .cbh and .cbv databases
Opened directly, in the browser or the Mac app. Read and never written; every game keeps the name of the database it came from.
The search mask
The same header and move conditions, combined with and, or and not, saved with your backups — or typed as a sentence: “Carlsen as Black in the Najdorf since 2018”.
Opening Report and the reference tree
An Opening Report from a population you name, with every source in its own column and its own game count. Never one blended figure.
Repertoire database
A repertoire keyed by position, so transpositions are the same line, with an inbox for new games, surprises and stale evidence.
Player preparation and the blunder check
Preparation against a named opponent, their repertoire against yours and drawn as an opening map, and a costly-moves report you can train from.
Mega Database
Not offered. Open, licensed populations instead — over-the-board broadcasts and high-rated online play — each kept separate.
Let’s Check and Engine Cloud
Not offered. Engines run on your machine: Stockfish 18 in the browser, native engines in the Mac app.
The engine panel with Stockfish 18 Lite running in the browser on the Italian Game: five ranked lines with their evaluations, the depth reached, and the best move drawn as an arrow on the board beside itThe engine panel with Stockfish 18 Lite running in the browser on the Italian Game: five ranked lines with their evaluations, the depth reached, and the best move drawn as an arrow on the board beside it

Engines

More than one way to see a position.

Stockfish 18 is in the browser, sandboxed and instant. On macOS, native engines install through Settings with their digest verified and their licence on the row. Two engines can run side by side.

Lc0 (Leela Chess Zero) is qualified on Apple Silicon. If you already have Syzygy files, Kingfisher can probe them locally.

Local-first

Your chess. Your machine.

Your studies, repertoire and notes live on your machine, and sign-in is optional — when you use it, your work follows you to every device. Reference data installs once and works offline. No cookies. Chess on your terms.

Get Kingfisher

One workspace. Two ways in.

macOSStable

The local workstation.

Apple Silicon. Signed and notarised — it opens like any other application.

  • Version1.5.5 · build 1277
  • Architecturearm64 (Apple Silicon)
  • Minimum OSmacOS 14 (Sonoma)
  • FileKingfisher-1.5.5-arm64.dmg · 193 MB
  • TrustSigned with Apple Developer ID · Notarised by Apple
Download for macOS

Apple Silicon · Notarised · Install guide · SHA-256 b04146414dee…

WebStable

The same application, in your browser.

Stockfish 18 runs in a Web Worker on the same origin. No install. No companion. Works on the train.

  • EngineStockfish 18 WASM
  • StorageIndexedDB · origin-scoped
  • BrowserModern · Chromium, Firefox, Safari
  • AccountNone
Open Kingfisher Studio

Source on GitHub

Frequently asked

Questions a new user actually has.

Is Kingfisher free?

Yes. The application is open source under the MIT licence. There is no paid tier, no subscription and no in-app purchase. Optional reference data is free to download; the manifests that come with the application tell you exactly how much each pack will use.

Do I need an account?

No. Kingfisher is local-first: open the web app or download the macOS application and your work lives in the browser or on the machine you installed it on, with every feature available signed out. An optional free account keeps the same studies, repertoires and analysis on every device you sign in on. You can also connect a Lichess or Chess.com account from Settings to study your own games.

Where is my work saved?

In your browser's IndexedDB on the web, or in ~/Library/Application Support/kingfisher-desktop/ on the macOS application. The full data lives on your machine. Sign in to the optional account and a copy follows you to every device you sign in on; without one, Settings → Database → Export backup / Import backup moves it as a portable JSON file you control.

Can I use Kingfisher offline?

Yes. The bundled Kingfisher Starter ships inside the application and answers from your machine. The macOS application runs entirely on your machine. The web build needs a network only for first load and for an optional, on-demand reference query; a downloaded pack keeps working without the network.

Is the macOS build safe to open?

Kingfisher 1.5.5 is signed with a Developer ID certificate and notarised by Apple, with the ticket stapled to the disk image and the application, so it opens with a normal double-click after macOS's standard "downloaded from the Internet" confirmation. Notarisation is Apple's automated malware screening, not an endorsement. The install guide lists the SHA-256 so you can check the file you have. Install guide.

Does Kingfisher work on Windows or Linux?

The web build works in any modern browser on any operating system. The desktop shell is supported on Apple Silicon macOS only. The web application is the same product, served from the same codebase; what differs is whether you run it in a browser tab or in the macOS shell.