Number 9 is the only value possible in cell (2,6).

Number 3 is the only value possible in cell (2,3).

Number 1 is the only value possible in cell (2,1).

Number 4 is the only value possible in cell (6,6).

Number 7 is the only value possible in cell (1,6).

Number 5 is the only value possible in cell (3,6).

Number 8 is the only value possible in cell (7,6).

For row 1, number 6 is only possible in cell (3,1)

For row 7, number 6 is only possible in cell (7,7)

For row 5, number 6 is only possible in cell (9,5)

For row 9, number 6 is only possible in cell (4,9)

For column 3, Number 2 is only possible in cell (3,3)

For row 4, number 3 is only possible in cell (8,4)

For row 5, number 3 is only possible in cell (1,5)

For box 4, candidates for 4 are all in column 3, so you can remove candidates from other blocks.

For box 3, candidates for 5 are all in row 1, so you can remove candidates from other blocks.

For box 1, candidates for 8 are all in row 2, so you can remove candidates from other blocks.

For blocks 3 and 6, candidates for 5 are all in the same two columns (7 and 9)

Naked Pair for 1 and 9, can remove these as candidates from other cells.

Naked Pair for 5 and 9, can remove these as candidates from other cells.

Naked Pair for 7 and 8, can remove these as candidates from other cells.

For box 3, candidates for 7 are all in column 7, so you can remove candidates from other blocks.

Naked Triple for 7, 8 and 9, can remove these as candidates from other cells.

Number 5 is the only value possible in cell (8,9).

Number 9 is the only value possible in cell (8,7).

X-Wing in rows for 9.

For row 8, number 9 is only possible in cell (6,8)

Either candidate for cell (4,2) forces 3 into cell (6,1).

Number 1 is the only value possible in cell (6,9).

Number 5 is the only value possible in cell (6,2).

Number 7 is the only value possible in cell (6,7).

Number 8 is the only value possible in cell (3,7).

Number 9 is the only value possible in cell (3,2).

Number 4 is the only value possible in cell (1,1).

Number 2 is the only value possible in cell (5,1).

Number 7 is the only value possible in cell (4,1).

Number 5 is the only value possible in cell (7,1).

Number 9 is the only value possible in cell (9,1).

Number 8 is the only value possible in cell (1,2).

Number 1 is the only value possible in cell (4,2).

Number 4 is the only value possible in cell (5,2).

Number 8 is the only value possible in cell (4,3).

Number 9 is the only value possible in cell (5,3).

Number 7 is the only value possible in cell (7,3).

Number 9 is the only value possible in cell (4,4).

Number 4 is the only value possible in cell (7,4).

Number 1 is the only value possible in cell (3,4).

Number 5 is the only value possible in cell (9,4).

Number 4 is the only value possible in cell (3,5).

Number 1 is the only value possible in cell (5,5).

Number 9 is the only value possible in cell (7,5).

Number 5 is the only value possible in cell (5,7).

Number 2 is the only value possible in cell (4,8).

Number 8 is the only value possible in cell (5,8).

Number 1 is the only value possible in cell (7,8).

Number 7 is the only value possible in cell (9,8).

Number 9 is the only value possible in cell (1,9).

Number 7 is the only value possible in cell (3,9).

Number 3 is the only value possible in cell (5,9).

Number 2 is the only value possible in cell (7,9).

Number 8 is the only value possible in cell (9,9).