Almost every chess site stops working the moment your signal does. LocalChess does not. The board, the rules, the computer opponent and the sound effects are all stored on your device the first time you visit, so you can put your phone in airplane mode and keep playing exactly as before.
This guide explains what actually gets stored, how to set it up in under a minute, which features keep working without a connection and which ones cannot, and how to check that it worked before you rely on it.
Why LocalChess works offline
Most online chess platforms are server-based. You make a move, your browser sends it to a server, the server validates it, asks an engine for a reply, and sends that back. Every single move is a network round trip. No connection means no game — and on a weak connection it means lag between every move.
LocalChess is client-side. There is no server in the loop at all:
- The board, the legal-move rules, and the opponent engine are plain HTML, CSS and
JavaScript that download once.
- Move generation and the engine's search run on your own device's processor.
- Your current game, board theme and settings are saved in your browser's local storage.
- A service worker — a small script the browser keeps after you close the tab —
holds a copy of every file the game needs.
That last piece is what makes offline play survive a reload. Without a service worker, a client-side game still plays fine in an already-open tab, but refreshing the page sends the browser back to the network for the HTML and it fails. With one, the browser serves the game straight from its own cache and never asks the network at all.
What gets stored on your device
The whole game is roughly half a megabyte — about the size of one phone photo. Specifically:
| Component | What it does | Size | | --- | --- | --- | | Game interface | Board, menus, move list, clocks | ~150 KB | | Chess rules engine | Legal moves, check, mate, stalemate | ~43 KB | | Stylesheet | Themes, layout, light and dark mode | ~67 KB | | Piece graphics | 12 SVG pieces, sharp at any size | ~8 KB | | Sound effects | Move, capture, castle, check, mate, promote | ~170 KB | | Page itself | The board markup | ~47 KB |
Nothing about your games is uploaded, because there is nowhere to upload it to. That is covered in more detail in our privacy policy.
How to set it up
- Open localchess.online once while you still have a connection.
- Let the page finish loading — wait until the pieces have rendered. This is when the
service worker installs and caches everything.
- Optionally, install it to your home screen so it launches like a native app:
- Android / Chrome — tap the ⋮ menu, then Add to Home screen. - iPhone / iPad, Safari — tap the Share button, then Add to Home Screen. - Desktop Chrome or Edge — click the install icon at the right of the address bar.
That's it. From then on the game opens instantly, connection or not.
How to check it actually worked
Don't take our word for it before a long flight — verify it takes ten seconds:
- Load localchess.online and wait for the board.
- Turn on airplane mode, or switch off Wi-Fi and mobile data.
- Reload the page.
If the board comes back, you're set. The reload is the important part — playing on in an already-open tab proves nothing, because the page was already in memory.
What works offline, and what doesn't
Everything that makes up a game of chess keeps working. The only things that need a connection are the ones that are inherently about reaching someone else.
Works with no connection:
- Playing the computer at all three difficulty levels
- Two-player pass & play on one device
- Every rule: castling, en passant, promotion, check, checkmate, stalemate, the
fifty-move rule and threefold repetition
- Undo, move list, and algebraic notation
- Chess clocks for bullet, blitz, rapid and classical
- Board themes, piece styles, light and dark mode
- Post-game analysis, since the engine that reviews the game is the same local engine
- PGN and FEN import and export
- Sound effects
Needs a connection:
- Play a friend online via a shared link. This connects two browsers directly to each
other, which obviously requires both of them to be online.
- Loading a blog article you have never opened before. Articles you have already read
are cached; new ones are not.
Where offline chess actually helps
- Flights — the single best use. No in-flight Wi-Fi, no paying for it either.
- Underground trains and tunnels, where a server-based site drops mid-move and loses
the position.
- Rural areas and road trips where mobile data fades in and out.
- Aeroplane-mode focus sessions, if you want to study without notifications.
- Strict school or office networks that block chess sites — once the page is cached,
there is nothing left for a filter to block.
- Capped or expensive data plans. After that first half-megabyte, playing costs you
nothing at all — no move ever touches the network again.
Offline play compared to the big platforms
| | LocalChess | Chess.com | Lichess | | --- | --- | --- | --- | | Play the computer offline in a browser | Yes | No | No | | Requires an account | No | For most features | No | | Moves sent to a server | Never | Yes | Yes | | Works in airplane mode after a reload | Yes | No | No | | Online opponents and ratings | Link-share only | Yes | Yes |
The trade-off is honest: server-based platforms give you matchmaking, ratings, tournaments and a huge opponent pool, and LocalChess does not try to replace those. What it gives you is a real game that is always there. We go into the differences in more depth in Chess.com alternatives and Lichess vs Chess.com.
Troubleshooting
The page didn't load offline. The most likely cause is that the first visit was cut short before caching finished. Reconnect, open the site, wait for the board to render fully, then test again.
It works in the browser but not from the home screen icon. On iOS, the installed app keeps its own storage. Open the installed icon once while connected, let it load, and it will work offline from then on.
I'm in a private or incognito window. Private browsing discards the cache when you close the window, so offline support won't persist. Use a normal window.
My saved game vanished. Clearing your browser's site data removes the cached game along with everything else. Export important games as PGN first.
Ready when you are
Offline chess turns dead time — a flight, a commute, a waiting room — into practice time. Open LocalChess once before your next trip, run the airplane-mode reload test, and you will always have a full-strength game in your pocket.
While you're set up, it's worth picking a repertoire you can drill against the bot: best openings for Black and best openings for White are good places to start, and how the LocalChess engine thinks explains what you are actually playing against.