News


Last week, KataGo released a major new neural network design based on transformers, using the same architecture that powers ChatGPT and other large language models. It turns out to work very well for Go, too (see this article).

AI Sensei's servers have already been updated to use KataGo's strongest transformer network, while keeping the same number of playouts at every quality level. The result is significantly stronger analysis across all membership plans, at essentially the same analysis speed, with fewer misreads in complicated fights.

We're very happy to help the Go community benefit from the excellent research and development work by David Wu and the other KataGo contributors!


It's been a while since the last AI Sensei update, but we've been working hard behind the curtains. This is the first of multiple updates that will land soon. It includes these new features:

Stone Sounds

Placing stones on the board (excluding navigating through the game) will now produce a proper sound, recorded from Benjamin's Japanese Goban. If you listen carefully, you might notice black and white are slightly different. You can disable that in the Preferences on the Board tab.

Initial White Stones

AI Sensei now supports analyzing positions or games with white stones in the starting position. That can be useful e.g. when using camera detection software or analyzing Go problems. We also updated the Record Game mode to support complex setup positions and set the starting player, while making it easier to place standard handicap stones.

Edit as New Game

Sometimes you uploaded a game with a recording mistake, wrong rules or komi, or you just want to analyze it again with a different quality. To do so, you can now use the Edit as New Game option from the top right menu and edit a copy of the game.


More ways to review your Go games with AI than ever before. Free tools, paid tools. Desktop apps that need a GPU, cloud tools that run in your browser. Some just show you the AI's opinion. Others help you learn from it.

This guide covers the main options in 2026: what each does well, where it falls short, and how to choose.

The Big Picture

Go analysis tools generally fall into two categories:

Desktop apps run KataGo on your own computer. These are free but require a GPU and some setup.

Cloud-based tools that run the AI on remote servers. These work on any device with no setup required.

Both use the same AI technology. The difference is where the computation happens and what the interface does with the results.

KaTrain (Free, Desktop)

What it is: Open-source desktop app that runs KataGo locally with a teaching-oriented interface.

What's good:

  • Completely free
  • Teaching mode pauses the game when you make a big mistake during AI play
  • Highly customizable: adjust AI strength, analysis depth, board display
  • Active open-source community

What's less good:

  • Requires local installation and a decent GPU
  • Desktop only, no mobile, no tablet
  • No community features or game sharing
  • Setup can be intimidating for non-technical users

Best for: Tech-comfortable players who have a GPU and want free, deep analysis on their desktop.

Lizzie (Free, Desktop)

What it is: Lightweight desktop frontend for KataGo and Leela Zero. One of the original tools that made AI analysis accessible.

What's good:

  • Free and open-source
  • Clean visualization of AI suggestions and win rate
  • Supports both KataGo and Leela Zero engines
  • Partial Japanese and Chinese UI support

What's less good:

  • Requires GPU and local installation
  • Desktop only
  • No learning features, purely an analysis viewer
  • Can be tricky to set up for beginners

Best for: Players who want a simple, free analysis viewer and already have KataGo set up.

Sabaki (Free, Desktop)

What it is: Modern SGF editor that can connect to external AI engines for analysis.

What's good:

  • Clean, modern interface
  • Good SGF editing tools
  • Can connect to KataGo or other engines

What's less good:

  • Requires external engine setup, doesn't include AI out of the box
  • Desktop only
  • English only
  • More of an editor than an analysis tool

Best for: Players who want a nice SGF editor with optional AI analysis on the side.

BadukPop (Freemium, Web + Mobile)

What it is: Go learning platform focused on gamified study and AI opponents.

What's good:

  • Mobile-first with iOS and Android apps
  • AI opponents from 20 kyu to 7 dan
  • Gamified learning approach

What's less good:

  • Limited post-game analysis depth
  • More focused on playing against AI than reviewing your own games
  • No multi-server import support

Best for: Casual players who want a fun, mobile-first way to practice against AI opponents.

AI Sensei (Freemium, Web + Android)

What it is: Cloud-based Go analysis platform focused on learning from your games. Uses KataGo for analysis with an interface designed to highlight what matters.

What's good:

  • Works in any browser without installation or GPU.
  • Training Mode lets you save key positions from your games and practice them with smart scheduling (like flashcards for Go). No other tool has this.
  • Imports from all major servers: Pandanet (one-click integration), Tygem (.gib), WBaduk (.ngf), OGS (.sgf), and more
  • Community features: share games and discuss positions with other players
  • Humanlike bots from 30 kyu to 9 dan across all board sizes
  • Japanese and Korean site localization
  • Android app available

What's less good:

  • No iOS app yet (in development)
  • Free analysis is strong but may occasionally misread complex positions. Paid plans are available if you want progressively deeper and more precise reading.

Best for: Players at any level who want to learn from their games. All features are free, including Training Mode, Quiz Mode, Challenge Mode, and game imports. Paid plans upgrade the analysis engine for stronger reading. Especially useful if you play on multiple servers or prefer mobile/tablet review.

Quick Comparison

KaTrainLizzieSabakiBadukPopAI Sensei
PriceFreeFreeFreeFreemiumFree (paid upgrades analysis depth)
PlatformDesktopDesktopDesktopWeb + MobileWeb + Android
GPU neededYesYesYesNoNo
SetupMediumMediumMediumNoneNone
Server importsSGF onlySGF onlySGF onlyLimitedSGF, GIB, NGF, UGF/UGI
Learning featuresTeaching modeNoneNoneAI opponentsTraining Mode
CommunityNoNoNoLimitedYes
MobileNoNoNoYesYes
LocalizationPartialPartialEnglishEnglishEN, JP, KR

So Which One Should You Use?

If you have a GPU and like tinkering: Start with KaTrain. It's free, powerful, and the teaching mode is genuinely useful. Lizzie is a good lightweight alternative.

If you want zero setup: AI Sensei. Open your browser, upload a game, done. The free tier is strong enough to find your biggest mistakes.

If you play on Asian servers: AI Sensei is the only tool that natively imports Pandanet, Tygem, and WBaduk files without conversion.

If you want to practice, not just review: AI Sensei's Training Mode is unique. No other tool turns your game positions into a practice system.

If you're on a budget: KaTrain (if you have a GPU) or AI Sensei's free tier (if you don't). Both give superhuman analysis at no cost.

If you want everything on your phone: AI Sensei or BadukPop. Both work on mobile: AI Sensei for analysis depth, BadukPop for casual AI play.

Many serious players use more than one tool. KaTrain for deep desktop analysis, AI Sensei for quick mobile review and training. They serve different moments in your study routine.

The Bottom Line

The best tool is the one you'll actually use. A free tool sitting unused on your desktop doesn't help. A paid subscription you review games with every week does.

Pick one, upload a game, start reviewing. That's where improvement begins.

Disclosure: This article is published on AI Sensei's blog. We've tried to be fair and accurate about all tools mentioned. If you spot an error, let us know at info@ai-sensei.com.


Every Go player hits a wall. You play regularly, do problems, watch lectures, and your rank just... stops moving. For some it's the double-digit kyu plateau. For others it's the jump to dan.

The usual advice is "play more games" or "do more tsumego." Those help. But there's a reason players get stuck despite doing both: they keep making the same mistakes without realizing it.

The Plateau Problem

What does a plateau look like from the inside?

You play a game. It feels like it could have gone either way. You're not sure where you went wrong. Maybe the opening felt okay but you lost in the middle game. Maybe you had a good position and it slipped away. The game ends and you think "I'll do better next time."

Next time, you make a similar mistake in a different position. Hard to see the pattern because the board looks different.

That's the problem. Without precise feedback, you can't identify what's holding you back. You end up working on everything a little instead of fixing the specific things that cost you points.

What Changes With AI Review

When you review a game with AI, the vagueness disappears. The analysis shows you exactly which moves lost the most ground. Not approximately, not "somewhere around here," but the specific move and the point cost.

The patterns become visible:

  • "I keep losing 5+ points in middle game fighting because my reading breaks down under pressure"
  • "My openings are fine, but I consistently play the wrong direction after the first fight"
  • "I'm giving away 2-3 points per endgame move because I don't know the correct sequences"

Concrete, measurable patterns that show up across multiple games. Once you can see them, you can fix them.

What to Focus on at Each Level

AI review is useful at every level, but the priorities shift as you get stronger.

Double-Digit Kyu (15k–10k)

At this level, games are often decided by a few big tactical mistakes: missed captures, groups dying unnecessarily, basic endgame blunders. AI review helps you spot these quickly.

Focus on: The 3-5 biggest point losses per game. These are usually tactical: life and death, capturing races, basic tesuji. Fix these and you'll jump several ranks.

Single-Digit Kyu (9k–1k)

The mistakes get subtler. You're not hanging groups anymore, but you're choosing the wrong direction, playing slow moves, or misreading the timing of invasions.

Focus on: Direction of play and whole-board thinking. When the AI says your move lost 4 points, look at why. It's usually a strategic choice, not a reading error. These are the mistakes worth saving to Training Mode for repeated practice.

Dan Level (1d–5d)

At dan level, the margins are thin. The AI might flag moves that lost only 1-2 points, but those small losses add up. Endgame technique, ko timing, and subtle positional judgements start mattering a lot.

Focus on: Patterns across many games rather than individual mistakes. If you review 10 games and the AI flags your endgame play in 8 of them, that's your priority, even if each individual error was small.

The Study Method That Actually Works

Improvement isn't about playing more games. It's about extracting more learning from each game. Here's a method that works:

After every serious game:

  1. Upload to AI Sensei and let the AI analyze it
  2. Look at your top 3 mistakes, the moves that lost the most points
  3. Understand each one. Don't just see the correct move, understand why it's better.
  4. Save the important ones. Hit "Remember" on positions you want to practice.
  5. Practice in Training Mode. Drill those positions until the correct response is automatic.

Weekly:

  • Review your Training Mode problems. The ones you keep getting wrong are your real weaknesses.
  • Look for patterns. Are the same types of mistakes showing up across games?

Monthly:

  • Step back and assess. Are the big mistakes from last month still appearing? If not, you've genuinely improved. If so, you need more focused practice on those patterns.

Focus Matters More Than the Tool

The AI is a tool. Powerful, but still a tool. It won't make you stronger by watching it play. It won't improve your reading by showing you variations you don't understand.

What it will do is show you exactly where to focus your limited study time. For most players, that focus is the difference between years of plateau and steady improvement.

Benjamin Teuber, AI Sensei's co-founder, went from strong amateur to German champion while building and using the tool. Not because the AI played for him, but because it showed him precisely where his game needed work.

Start With Your Last Game

You don't need to overhaul your study routine. Just start with one game.

Upload your most recent serious game to ai-sensei.com. Look at the three biggest mistakes. Understand them. Save the most important one to Training Mode.

That's it. One game, three mistakes, one practice position. Do that consistently, and you'll be surprised how quickly the wall starts to crack.

AI Sensei analyzes Go games at every level, from beginner to dan. Free analysis at ai-sensei.com.


Most Go players have a home server. Pandanet for the community and pro tournaments. Fox for the biggest player pool in Asia. Tygem for fast-paced competition. WBaduk because that's where your friends play.

When it comes to reviewing your games with AI, none of that should matter. A good move is a good move, whether the game file ends in .sgf, .gib, or .ugf.

The Multi-Server Problem

The frustrating part: you play on one platform, but the best analysis tools might not support your file format. Or you play on multiple servers and now your games are scattered across different formats with no single place to review them.

Pandanet uses UGF and UGI files. Fox and most Western servers use SGF. Tygem saves games as GIB. WBaduk uses NGF. They're all just records of the same thing, a sequence of moves on a Go board, but the formats are different enough that most tools only support one or two.

One Tool for Everything

AI Sensei supports all of them:

  • Pandanet (.ugf, .ugi): direct one-click integration from GoPanda2
  • Fox (.sgf): upload your downloaded game files
  • Tygem (.gib): upload your downloaded game files
  • WBaduk (.ngf): same simple upload process
  • OGS, KGS, and others (.sgf): the universal Go format

Upload the file, and AI Sensei handles the rest. The analysis is identical regardless of format: the same KataGo engine, the same depth, the same results.

The Pandanet Integration: Even Easier

If you play on Pandanet, you don't even need to download a file. The GoPanda2 client has a built-in button that uploads your game directly to AI Sensei after you finish playing. One click, and your game is being analyzed.

You can also log into AI Sensei with your Pandanet credentials. No need to create a separate account.

AI Sensei and Pandanet have been partners since 2022. The integration was built to be smooth. Finish your game, click the button, grab a coffee, and your review is ready.

For Fox, Tygem, and WBaduk Players

If you play on Fox, Tygem, or WBaduk, the process is almost as simple. After your game:

  1. Download your game file from the server (Fox saves .sgf files, Tygem saves .gib, WBaduk saves .ngf)
  2. Upload to AI Sensei at ai-sensei.com
  3. Review in minutes. The AI analyzes your game and highlights your key mistakes.

That's it. No format conversion, no special tools needed. AI Sensei reads the file natively.

For players who use multiple servers, this is especially useful. All your games, regardless of where they were played, end up in one place with consistent analysis. Your Pandanet evening league game sits next to your Fox ranked match and your Tygem blitz session, all reviewed with the same AI.

Why This Matters for Improvement

Having all your games in one place helps your development. You can spot patterns across different time controls and opponents. Maybe you play solid on Pandanet's longer time settings but fall apart in Fox or Tygem blitz. Maybe your WBaduk games reveal a weakness in a specific opening.

One review tool across all your games means one complete picture of your strengths and weaknesses.

Works on Any Device

Since AI Sensei runs in your browser, you can upload and review from anywhere. Upload a game from your phone right after a tournament round, or review last night's Tygem games on your tablet over breakfast.

No software to install. No GPU required. The heavy computation happens in the cloud. You just need a browser and your game file.

Getting Started

Pandanet players: Look for the AI Sensei button in GoPanda2 after your next game. One click and you're done.

Fox / Tygem / WBaduk players: Grab your latest game file and upload it at ai-sensei.com. All features are free. The AI's positional judgement is superhuman, though it may occasionally misread complex tactical positions.

Everyone else: If you have an SGF file, you're good to go. OGS, KGS, any server that exports SGF works.

Whichever server is home, the analysis is the same. Upload your game and find out where the real turning points were.

AI Sensei supports SGF, GIB, NGF, and UGF/UGI files. All features free at ai-sensei.com. Pandanet integration live since 2022.