Catan Trainer
The Best Colonist.io Chrome Extensions in 2026 (and Which Ones Are Allowed)
There are more than a dozen Chrome extensions for Colonist.io, most of them card counters, and most of them abandoned. This is the list as of November 2026 with user counts and last-updated dates from the Chrome Web Store, what each one actually does, and the one question that matters before you install any of them: does Colonist allow it? Full disclosure: we make one of these (the post-game review tool at the end). We have tried to be as blunt about ours as about the rest.
First, the rule
Colonist's community guidelines have one line on the subject:
Don't use extensions or any third-party tool that plays for you or shows hidden information.
Cheating can get an account banned right away. Read the line carefully, because it draws a precise boundary:
- Plays for you: anything that clicks, builds, trades or ends turns on your behalf. Out.
- Shows hidden information: anything that reveals what you could not know by watching, such as an opponent's actual hand, the next card in the dice deck, or a development card's identity. Out.
- Everything else is public information. The game log on Colonist is visible to every player: every roll, every trade, every build, every "stole a card" line. An extension that tallies that log is doing arithmetic you are allowed to do on paper. That is why every serious tracker below describes itself as reading only the public log.
Two cautions. First, "only public information" is the developer's claim, not Colonist's endorsement; none of these tools is official and Colonist has not published a list of approved ones. Second, a tool that infers a hidden card from public events (the robber stole from a player who had only wheat) is still working from public information, but a tool that reads the hidden card from the page's data is not, and from the outside the two can look identical. Prefer open-source tools, where you can see which it is.
The extensions, by what they do
Card counters and resource trackers
The biggest category. All of them watch the game log and estimate what each player is holding, and all of them get fuzzy after an unseen robber steal, which they resolve with varying cleverness.
| Extension | Users | Rating | Last updated | Notes |
|---|---|---|---|---|
| Colonist Card Counter | ~860 | 3.8 (24) | Sep 2023 | The most installed. Tracks each player's resources and works out unknown robberies from later builds and trades. English-language Colonist only. No update in over two years. |
| Colonist IQ | ~520 | 2.7 (7) | Apr 2023 | Chat-log tracker with opponent hand estimates and robber resolution; states it uses only the public log. Includes an ad blocker. Low rating, old. |
| Colonist Buddy | ~270 | 4.0 (10) | May 2026 | Dice rolls, resource counts, development cards and roll predictions in a clean overlay. The best-rated tracker that is still being updated. |
| Colonist Companion | ~120 | 5.0 (2) | Feb 2026 | Resource estimates from the log, dev-card usage, dice stats, draggable overlay. Open source on GitHub. The author notes it works well in 1v1 and struggles to parse four-player games. |
| Catan Card Tracker for Colonist.io | ~80 | 5.0 (1) | Apr 2026 | Card tracking plus dice statistics, a win predictor and a "luck" measure; says it accesses no private data. |
| Colonist Resource Tracker | ~165 | 2.3 (3) | Aug 2023 | Estimates each player's resources from their moves. Lowest rated, not updated. |
| Colonist.io Counter | ~320 | 3.7 (3) | Feb 2022 | Counts cards in the bank only. The planned hand-tracking features were never built. Effectively abandoned. |
Our pick: Colonist Buddy if you want something maintained with a good interface; Colonist Companion if you want to read the source. Skip the three that have not been updated since 2023; Colonist changes its client and these break quietly.
A note on whether a tracker will raise your rating. Knowing an opponent holds two wheat helps on the margin in the mid-game. It does nothing for the decision that decides most Colonist games, which is where your first two settlements went. More on that below.
Game recorders
- Colony Historian (~30 users, Nov 2023). Saves each finished game to your computer as a JSON file, which you can load into the developer's online viewer or analyse yourself. Fan-made, unofficial, open source. The right tool if you want raw game data.
- Colonist.io (result collector) (~100 users, Aug 2021). Publishes completed game results to a public database and lets you look up statistics other players recorded. Five years without an update.
Quality-of-life
- Colonist+ (~80 users, Jan 2026). Removes ads and enables full-screen play, with custom avatars and player colours as a paid tier ($0.50 a month or $4.50 a year after a trial). Note that Colonist Card Counter and Colonist IQ also strip the in-game panel ads as a side feature. Whether you think ad removal is fair to a free game is between you and Colonist; it is not covered by the cheating rule.
In-game advisors: the ones to be careful with
A newer category overlays live recommendations during the game: where to build, when to play a knight, who to rob. Two examples are Catan Copilot, a Firefox add-on loaded from source, and a Chrome listing called CatanBot: Colonist HUD that appears only in "related" lists. Advice from public information is, strictly, on the allowed side of Colonist's line. But Catan Copilot ships an experimental "Autopilot" that rolls, builds and ends turns for you when switched on. That is a tool that plays for you, by definition, and an account caught using it should expect a ban. If you try an advisor, keep anything that automates switched off, and understand that you are closer to the line than with a card counter.
Not extensions, but worth knowing
- Catan Lens: a free web app, not an extension, that scores every legal corner on a board you enter by hand, with a drill mode and a snake-draft simulation. Unofficial, open source. It does not connect to Colonist, so you type the board in yourself.
- Colonist's own log: free, built in, and the only tool every top player actually uses. Every roll, trade and build is there after the game.
Post-game review: Catan Trainer for Colonist
This one is ours, so judge the claims accordingly. Catan Trainer for Colonist does nothing during a game. When a base four-player game ends, it sends the board and the eight opening placements to Catan Trainer, which grades your two settlements against the best corners that were available at the moment you picked, and explains the difference: pips, scarcity, the plan the board wanted, ports priced by the roads you still had to build, and how your two settlements fit together. There is a card-counter-free reason we built it this way: on Colonist, where opponents are fast and rarely blunder in the mid-game, the opening is the decision that separates ratings, and it is the one decision you can judge without the dice getting in the way.
Limits, honestly: base map, four players only (no 1v1, no expansions yet), Chrome only, and the review is of your placements, not your trades or robber play. It is free to try, with a paid tier after a number of reviewed boards.
How to choose
- Check the update date before the rating. Colonist's client changes; a tracker from 2022 is probably counting nothing.
- Prefer open source when the extension reads the game, so you can see it is reading the log and not the page's hidden data.
- Never enable anything that acts for you. Advice is a grey area at worst; automation is a ban.
- Pick the tool for the decision you are actually getting wrong. If your rating is flat, that is almost always placement, not card counting.
Review your real Colonist openings
Connect the free extension once, play as usual, and get a graded review of your two placements after every base four-player game. Nothing runs during play.
Connect Colonist →