Decide how you’re using cranberry sauce: as a spoonable side, or as an ingredient in baking (bars, muffins, stuffing glazes).
Choose the closest tart-sweet match: red currant/lingonberry for tart fruit spread, raspberry compote for fresh-style tartness.
Use the listed ratio; then adjust tartness with lemon juice (jam) or thickness with a quick simmer (fruit).
If the substitute is runnier than cranberry sauce, simmer 3–5 minutes until spoonable; if it’s too thick, loosen with 1–2 tablespoon water.
Taste before serving or baking—cranberry sauce should read tart first, sweet second.