Charles Ellicott Commentary 2 Kings 18:5

"He trusted in Jehovah, the God of Israel; so that after him was none like him among all the kings of Judah, nor [among them] that were before him." — 2 Kings 18:5 (ASV)

He trusted ... Israel. — In Jehovah, the God of Israel he trusted. Hezekiah is thus contrasted with idolatrous kings, such as those who trusted in the Nehushtan.

After him was none like him among all the kings of Judah. —This does not contradict what is said of Josiah (2 Kings 23:25). Hezekiah was preeminent for his trust in Jehovah, Josiah for his strict adherence to the Mosaic Law.

Nor any that were before him. —Rather, nor among those that were before him.