Free GTO poker solver
GTOZero is a heads-up postflop solver that calculates on your own device, plus hand review, precomputed flop strategies and a trainer that grades every decision by EV loss. Nothing to install, nothing to pay.
Opens the solver web app in your browser
A GTO solver takes two ranges, a board, the pot, the stacks and the bet sizes you allow, then searches for a strategy neither player can improve on alone. The output is not one move but a frequency for every hand: how often to bet, check, call, raise or fold. GTOZero is an online poker solver that runs that search inside your browser, so you can test the exact spot you played instead of the closest chart.
Enter both ranges, the flop (and a turn or river if you want a fixed runout), the starting pot, the effective stack and bet and raise sizes for each street. The calculation runs on your computer's CPU through WebAssembly — nothing is sent to a server to be solved. It stops at the target exploitability you set (0.3% of the pot by default) or at the iteration limit.
Thirteen worked examples open instantly. Press ⚡ View results and the flop strategy appears straight away, so your first session can be about reading frequencies, equity and EV rather than settings. To change the ranges or follow the hand to the turn and river, Solve it yourself loads the same inputs into the solver.
Pick the situation (Open · Call, 3-bet pot or 4-bet pot), the seats, your two cards and the flop, then enter the actions in the order they happened. Each decision comes back as Best play, Acceptable or Review this play, with a Total loss in big blinds. Flop decisions use precomputed results; turn and river decisions are calculated on your device. Ranges come from the app's preflop charts, so there is nothing to type. The basis is online 6-max cash with 100bb stacks, heads-up pots only.
For the main seat combinations of single-raised, 3-bet and 4-bet pots, all 1,755 distinct flops (suit-swapped flops counted once) have been solved in advance to a 0.3% target. Flop study shows one flop: action frequencies and a 13×13 strategy grid, and you can follow each action to the end of the flop. Flop reports averages all 1,755 flops, weighted by how often each one is dealt, grouped by high card, suits, pairing or connectedness. In these pots flop bets are fixed at 33% and 75% of the pot with 60% raises. Turn and river play is not stored — Open in solver calculates it from there. A small blind vs. big blind limped pot is also available with a free account.
The trainer deals hands from solved spots in proportion to how often you would really hold them, asks for your action, and grades it by EV loss relative to the pot: Best play, Acceptable or Review this spot. A Daily Puzzle, a Review queue, Leak Finder and an optional RNG mode for mixed strategies are built in. From any result screen, Practice this spot turns your own solve into trainer questions.
On the results screen, Lock this node’s strategy fixes how one player acts at that point. Re-solve and compare before and after to see how the other player's strategy should shift when an opponent makes a mistake — for example, folding too often to a river bet.
Open a Study Spot first, so you know what a finished result looks like. Then build your own spot through the five tabs on the left, in order:
Chips are entered as whole numbers; the app suggests 10 chips = 1bb. If a tree needs more memory than the browser allows (about 3.9GB), switch Precision mode to 16-bit integer or simplify the tree.
Four short walkthroughs on the HoldemMaster YouTube channel, recorded on the same app.
Yes. Custom solves, Study Spots, hand review, Flop study, Flop reports and the GTO Trainer are free and work without an account. Newer advanced features — the limped pot is the first — need a free account, which you can create with Google or Telegram. There is no paid tier.
No. The solver is a web app built on WebAssembly and opens in Chrome, Edge, Firefox or Safari. You can add it to your home screen if you want it full screen, but that is optional.
On your own device. Your browser downloads the solver engine and uses your CPU, so a faster computer solves faster. Precomputed flops for hand review and Flop study are downloaded only for the flop you open.
Accuracy is measured as exploitability: how much an opponent could gain against the strategy, as a percentage of the pot. Custom solves aim for 0.3% by default, and the precomputed flops were solved to 0.3%. Results are only as good as the ranges and bet sizes you give the solver.
No. It solves heads-up postflop spots. For preflop the app has reference charts, which are consensus ranges from public material rather than solver output.
Yes. Study Spots, hand review, Flop study and the GTO Trainer all run on phones. Custom solves are best done on a desktop browser, especially on iPhone, where Safari limits the solver to one thread.
Not for the core features. Only the limped pot needs a free account. Signing in also lets your GTO Trainer history, saved ranges and bet settings follow you to other devices. Without an account you can save up to 10 ranges and 10 bet settings.
The team behind the HoldemMaster YouTube channel. The solver engine is a fork of the open-source WASM Postflop project (AGPL-3.0), and the modified source code is public on GitHub.
The engine is based on WASM Postflop by Wataru Inariba, released under AGPL-3.0. GTOZero is a localized and extended version with hand review, precomputed flop data and the trainer, and publishes the full modified source under the same license.
Why it is free: we want more players to enjoy hold'em through objective, solver-based analysis rather than guesswork. We want solver study to be open to every player, so we made the solver free and added Study Spots, video guides and a trainer that teach you how to read the results and apply them to your own hands. The goal is simple — to help as many players as possible get better at hold'em.