A desktop poker GTO solver for No-Limit Hold’em postflop spots
Build your GTO library with one-click setup. ART/GTO Solver is a Windows desktop application that solves one No-Limit Hold’em postflop spot at a time on your own machine. You give it a flop, a range for each player, the pot and effective stack the preflop action left behind, and the bet sizes you want in the tree. It runs Discounted CFR on your CPU or, much faster, on your graphics card, and writes the result to disk as a file you keep.
What the solver does
ART/GTO Solver solves one postflop spot at a time. You set the flop, a range for each player, the pot and the effective stack, and the bet and raise sizes the tree may use. Leave the turn and river empty and it solves the whole game from the flop, covering every turn and river card. Solving starts at the flop — this is a postflop solver, not a preflop one. The engine is Discounted CFR (Brown & Sandholm, 2019) running on your CPU threads, and you set the iteration cap and the exploitability target it stops at. How the solver works →
Set up a spot
Ranges go in through the Range Editor: a 13×13 grid you paint with a weight brush at any weight between 0 and 1, or a text box you paste a written range into — shorthand like JJ+ and AKs:0.5, or specific combos — and parse. Bet sizes are comma-separated percentages of the pot, set per street and per player, with their own raise sizes, donk bets for the turn and river, and a cap on raises per street. The app opens with presets for 100bb cash already loaded, so you can queue a solve without opening a settings panel. Ranges → Bet sizing →
Batch solving with presets
Multi Job turns dimensions into a batch instead of one job at a time. Pick a pot type — SRP, 3BP, 4BP or 5BP — the position pairs you want, a flop set (25, 74 or 184 representative flops, all 1,755 strategically distinct ones, or a single board you type), and a bet-sizing profile for the in-position and the out-of-position aggressor case. One click expands that into one job per position pair, each with the ranges, pot, stack and sizes that belong to it. The queue survives restarts, so an overnight batch picks up where it stopped. Multi-job batch →
Your results, in an open format
Every solve is saved as .art, the app’s native file, and exports to .artgto: one file per spot, zstd-compressed CBOR, with the byte layout and the node structure documented on this site. Any language with a CBOR and a zstd library can read it. The Library tab exports whole folders in a batch — a target pattern fills in every destination at once, and “skip already exported” makes a long export resumable. Library and export → The .artgto format →
Study the results
Inside the app, the strategy browser shows the solved spot: the 13×13 grid coloured by action, the mix for a single combo, EV and equity, and a game tree you can walk node by node. Away from the solver, ART/GTO Viewer — a free download — reads your .artgto exports in any browser on PC, Mac or Linux, served from your own disk by a one-line static HTTP server. You can also try that interface with nothing installed: the browser viewer at /try/ comes with a demo spot and 100bb preflop ranges. Open the browser viewer → About the Viewer →
Requirements and download
ART/GTO Solver is a native Windows application. It needs an x86-64 CPU with AVX2 — roughly any chip from 2013 onward — and enough RAM to hold the tree you are solving; deeper stacks and more bet sizes per street need more of it. A graphics card is optional: one with Vulkan or Direct3D 12 can take the solve instead. Disk space depends on how many solved spots you keep. The app is in open beta. System requirements →
FAQ
Does it solve preflop? No. Solving starts at the flop. You give the solver a preflop range for each player, plus the pot and effective stack the preflop action left behind, and it takes the hand from the flop to the river. If you need ranges to start from, the free 100bb 6-max charts under /learn/ cover opens, 3-bets and 4-bets, and the app ships with range presets for the common pot types.
Do I need an internet connection to solve? No. Solving works offline, and there is no cloud connection during a solve — the spot never leaves your machine. A connection is needed twice: once to activate your licence, and then whenever you want to check for an update.
Can I open results without the solver app? Yes. ART/GTO Viewer is a separate, free download that opens your .artgto library in a browser on PC, Mac or Linux, and the browser viewer at /try/ shows the same interface with nothing installed. Because the format is documented, you can also read an .artgto file yourself in any language that has a CBOR and a zstd library.