Mudoku — is it actually getting popular?

Competitive read for sudoky.net · desk research, 16 August 2026 · ellsworth

Short answer: no, and the name is probably wrong. Mudoku.io — the competitive multiplayer Sudoku site — sits at global rank #13,631,262 with traffic down 36.6% month-on-month. The Steam game of the same name has zero user reviews two years after release.

The sudoku-adjacent product that is growing is spelled differently: Murdoku — murder-mystery sudoku — at roughly 17,000 downloads and ~450/day over the last 30 days, with a real TikTok presence. One letter apart, opposite trajectories.

Three different products share the name

Product	What it is	Evidence of traction
Mudoku.io web + Android	Real-time 1v1 sudoku race on one shared board. ELO matchmaking, 6-character friend invite codes, 3/5/10-minute formats, streak bonuses, global leaderboards. Free, no download.	Global rank #13.6M −36.6% MoM 28s avg visit · 1.81 pp/visit NOT GROWING
Mudoku – next Sudoku Steam, €2.99	Single-player. Slide and move whole lines to complete the grid — an action-puzzle hybrid, not multiplayer. Coremedia, inc.	Released 16 Mar 2024 0 user reviews NOT GROWING
Murdoku Android, free	Murder-mystery sudoku: every filled square advances a detective story, clues read like a novel. No multiplayer at all.	~17,000 downloads ~450/day (30d) On Play since ~Jun 2026 GROWING

Confidence, stated honestly. The Mudoku.io numbers come from SimilarWeb's free tier, which reports "No Data to Display" for most categories at this site's size — the composition figures (73% Chile / 27% Spain) are almost certainly a handful of sessions and should not be read as a market. The rank, the direction of travel and the absence of data are the reliable signals, and all three say the same thing. I could not obtain an Android install count for Mudoku.io: the Play listing and AppBrain both refused automated fetches (403). No Show HN, no Reddit thread, no press coverage beyond a syndicated Kotaku game-database stub.

What Mudoku.io has that sudoky.net does not

Worth taking seriously regardless of their traffic, because they converged on the same design as us in several places — which is at least evidence the design is the obvious one.

Mechanic	Mudoku.io	sudoky.net duel
Shared board, live race	yes	yes
Wrong digit = 3-second freeze	yes	yes — identical, and ours is also an anti-oracle measure, not just a penalty
Opponent progress visible, digits hidden	progress only	yes — server-enforced, asserted in two test suites
Friend invite	6-character code	yes — shareable URL
Streaks · difficulty levels · rematch	yes	yes
Matchmaking against a stranger	yes — ELO-rated queue	MISSING invite-link only
Fixed-length formats (3/5/10 min)	yes	MISSING race-to-finish only
Global competitive ladder	ELO + leaderboard	partial — daily leaderboard exists, duels are not rated

The gap that matters is the first one. Our duel requires you to already have a friend who wants to play sudoku right now, and the duel-server README names the cost in its own words: the long idle stretch while a host waits for a friend to open the invite. A duel that cannot be started alone is a feature you have to organise, not a button that always works.

The finding that should change what we do

Mudoku.io has ELO matchmaking and is at rank #13.6M. Building the one thing we are missing would make us match a product that the market is not rewarding. That is the strongest argument available against spending a sprint on duel matchmaking, and it came free with checking the premise.

Meanwhile Murdoku has no multiplayer whatsoever and is doing ~450 downloads a day on two things we can actually copy:

Narrative wrapped around the same grid. The sudoku is unchanged; what changed is that finishing a square advances a story. This is the identical insight to the Анекдотник thematic pages — authored editorial over a corpus that already exists — and we have already built that machinery once.
Short-form video as the distribution channel. Murdoku's visibility is a TikTok cluster, not SEO and not an app-store category. A puzzle whose solution reveals a story is natively watchable; a race between two strangers is not.

What I would put in front of the owner

Do not build duel matchmaking on this evidence. The one competitor who has it is not being rewarded for it.
The transferable idea is narrative, not competition — and sudoky.net already has the closest thing to it in /obuchenie and the daily technique chain, which are authored content over a generated grid.
Nothing here is urgent. Anekdotnik is at 0₽ revenue against ~10,050₽ spent and РСЯ is one merge away. This is a note for when sudoky.net next gets a turn, not a reason to give it one.

Method

Desk research only, 16 August 2026. Sources: mudoku.io, its Google Play listing, the Steam store page for Mudoku – next Sudoku, SimilarWeb's free traffic report for mudoku.io, AppBrain and Google Play listings for Murdoku, and TikTok's Murdoku discovery pages. Our own side is read from the sudoky working copy on this box: CLAUDE.md, js/duel.js, duel-server/README.md and duel-server/src/room.js. The "missing" rows in the comparison table were verified by grep returning nothing for matchmaking, queue and random-opponent across the duel client and both server implementations — absence of a code path, not absence of a mention in the docs.

Not verified: Mudoku.io's Android install base, its revenue model beyond "free, no paywalls" as claimed on its own site, and whether its traffic decline is a seasonal artefact or a trend — one month of SimilarWeb data cannot distinguish those.