Number 9 is the only value possible in cell (2,1).

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

For row 1, number 1 is only possible in cell (7,1)

For row 9, number 1 is only possible in cell (9,9)

For column 4, Number 8 is only possible in cell (4,7)

Number 4 is the only value possible in cell (9,7).

Number 8 is the only value possible in cell (9,3).

For row 7, number 1 is only possible in cell (6,7)

For row 3, number 1 is only possible in cell (4,3)

For row 8, number 6 is only possible in cell (7,8)

For column 4, Number 5 is only possible in cell (4,8)

Number 9 is the only value possible in cell (3,8).

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

For box 8, candidates for 9 are all in column 5, so you can remove candidates from other blocks.

For box 9, candidates for 7 are all in row 7, so you can remove candidates from other blocks.

For box 3, candidates for 2 are all in row 2, so you can remove candidates from other blocks.

For box 8, candidates for 2 are all in column 5, so you can remove candidates from other blocks.

For box 3, candidates for 4 are all in row 2, so you can remove candidates from other blocks.

Candidates for 6 in boxes 5 and 6 force the candidates in box 4 to be in the remaining line.

Candidates for 4 in boxes 2 and 8 force the candidates in box 5 to be in the remaining line.

Naked Pair for 3 and 6, can remove these as candidates from other cells.

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

Hidden Pair for 2 and 4, can remove other candidates from these cells.

Either candidate for cell (6,6) forces 2 into cell (7,4).

Number 4 is the only value possible in cell (7,2).

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

Either candidate for cell (8,4) forces 4 into cell (1,5).

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

Number 3 is the only value possible in cell (4,2).

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

Number 7 is the only value possible in cell (8,4).

Number 6 is the only value possible in cell (2,4).

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

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

Number 4 is the only value possible in cell (5,1).

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

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

Number 8 is the only value possible in cell (7,5).

Number 7 is the only value possible in cell (3,5).

Number 8 is the only value possible in cell (3,2).

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

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

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

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

Number 6 is the only value possible in cell (1,3).

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

Number 7 is the only value possible in cell (6,3).

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

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

Number 6 is the only value possible in cell (9,5).

Number 8 is the only value possible in cell (2,6).

Number 2 is the only value possible in cell (3,6).

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

Number 4 is the only value possible in cell (8,6).

Number 3 is the only value possible in cell (9,6).

Number 2 is the only value possible in cell (1,7).

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

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

Number 5 is the only value possible in cell (8,7).

Number 7 is the only value possible in cell (5,8).

Number 4 is the only value possible in cell (6,8).

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

Number 2 is the only value possible in cell (5,9).

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

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