Chocolate chunks vs chocolate chips

Chips are formulated to hold their shape; chunks are usually ordinary chocolate that melts into pools. Opposite design goals.

Why these get confused

Both are sold as baking pieces on the same shelf, so the choice looks like size alone. The formulation difference matters more than the size does.

	Chunks	Chips	Why it matters
Formulation	Usually ordinary chocolate.	Reduced cocoa butter, sometimes with added stabilisers.	This is the real difference. Chips are engineered not to melt; chunks are not.
Behaviour in a bake	Melt into molten pools and streaks.	Hold their shape and stay as distinct pieces.	Choose by the result you want, not by size. Gooey cookies want chunks; a cookie with visible discrete pieces wants chips.
Melting for other uses	Melts and behaves normally.	Melts thickly and does not coat well.	Never melt chips for coating or tempering — the property that makes them good in a cookie makes them useless out of it.
Cheapest equivalent	A chopped bar behaves identically and usually tastes better.	No equivalent. The formulation is specific.

When you want molten pockets, and whenever a chopped bar would do — which is most of the time.

When you want the pieces to still be pieces after baking.

Chocolate chunksSet against Chips, which readers frequently believe is the same thing.
Chocolate chipsSet against Chunks, which readers frequently believe is the same thing.

ChocolateHQ editorial synthesis — ChocolateHQ(citation identity confirmed; passage not re-read)
The Science of Chocolate — Royal Society of Chemistry(citation identity confirmed; passage not re-read)