Feathery green fronds with a sweet, grassy, faintly aniseed aroma carried by carvone - the same compound that dominates caraway.
What it does in a recipe: A cool, sharp finish for fish, cucumber, yoghurt and potatoes, added late because its oils are volatile and heat-sensitive. Pick the swap that covers that job - the ratios below are written so you can act on them without doing any arithmetic.
Dill seed and dill weed are not interchangeable. The seed is far more pungent and closer to caraway, and belongs in pickling brine rather than on a plate of salmon.
At a glance
Fresh dill in summary
Fresh dill at a glance: category, its job in a recipe, the diets it suits, the diets its substitutes can satisfy, and how many substitutes there are.
Can I use fresh fennel fronds instead of fresh dill?
1 tbsp chopped fresh dill = 1 tbsp chopped fennel fronds. Fennel fronds look almost identical and carry a related sweet-anise aroma, so they cover both dill's appearance and much of its flavour. Sweeter and more openly aniseed. In a cucumber salad this reads as a variation rather than a mistake.
Can I use fresh tarragon instead of fresh dill?
1 tbsp chopped fresh dill = 2 tsp chopped fresh tarragon. Tarragon's estragole gives a comparable sweet-anise lift and suits the same fish and cream dishes, but it is stronger, so use about two thirds. More perfumed and more French. A gravlax or a dill pickle will taste clearly different.
Can I use dried dill weed instead of fresh dill?
1 tbsp chopped fresh dill = 1 tsp dried dill weed. The 3:1 fresh-to-dried ratio applies here as it does to other soft herbs, though dill loses more than the woody herbs do. Flatter and hay-like, with much of the fresh sharpness gone. It is serviceable in dips and disappointing as a garnish.
Can I use fresh flat-leaf parsley and a pinch of caraway instead of fresh dill?
1 tbsp chopped fresh dill = 1 tbsp chopped parsley + a scant 1/8 tsp ground caraway. Parsley supplies the green body, and caraway supplies the carvone that gives dill its characteristic note - the two compounds are the same. Approximate rather than convincing, and caraway brings a rye-bread association dill does not have.
Cooking around an allergy? Diet tags here describe the ingredient itself, not any particular brand. Processed products change formulation without notice and shared production lines are common, so read the label on everything you use. A severe allergy is a medical matter - confirm with the manufacturer or your clinician rather than relying on a substitution chart.