Unicode / ASCII arrows in 8 directions?
As an alternative to the ones already suggested user Lynn, there are wider arrows at code points U+27A1 and U+2B05 through U+2B0B:
⬉ ⬆ ⬈
⬅ ⊙ ➡
⬋ ⬇ ⬊
Here they are:
↖ ↑ ↗
← · →
↙ ↓ ↘
Their codepoints are U+2190 through U+2193 for the orthogonal arrows (left, up, right, down) and U+2196 through U+2199 for the diagonal ones (up-left, up-right, down-right, down-left).