An ordinary sudoku, plus thermometers: digits get bigger along every thermometer, starting from its round bulb. Rows, columns and boxes still hold 1 to 9 exactly once.
About Mercury
Mercury is a free daily thermo sudoku from Mind Loft. Each day gives you a 9×9 sudoku with thermometers drawn on the grid: along every thermometer the digits strictly increase from the round bulb to the tip. Rows, columns, and 3×3 boxes still hold 1 through 9 exactly once, and the thermometers plus a handful of printed digits carry the rest.
There is no arithmetic anywhere: the thermometers are pure ordering, which makes this the most visual sudoku on the slate. Every board has a single solution you can always reach by logic, with no guessing. Wrong entries are never flagged, so spotting your own slips is part of the puzzle, and a clean solve scores a perfect 10 with the daily leaderboard decided on the clock.
A new board drops every day at midnight Eastern; weekdays print fewer digits as the week goes on, and the Sunday Edition prints just eight and lets nine thermometers do the work. No app, no signup, play free in your browser. Want the rest of the family? Try Suds, the classic 9×9, Cages, the killer sudoku, and Polka, the kropki with no numbers at all.
Mercury, in short
How do you play Mercury?
Thermo sudoku: digits get bigger along every thermometer from its round bulb, and the ordering does the work no sums are asked to do. Sundays print just eight digits under nine thermometers.
Is Mercury free to play?
Yes. Mercury is free to play in your browser on Mind Loft, with no app to install and no account required.
When does a new Mercury puzzle come out?
A new Mercury arrives every day at midnight Eastern time, and Sundays bring the Sunday Edition, the biggest or hardest board of the week.
What kind of puzzle is Mercury?
Mercury is a daily sudoku from Mind Loft: the daily thermo sudoku. It is part of the daily sudoku lineup.
Can I play past Mercury puzzles?
Yes. Every past Mercury board is in the puzzle archive, a tap away by day.
What other daily sudoku does Mind Loft have?
Knight, Diag, Frame and Rim, among others. The Sudoku page lists every one, with a new board for each every day.