Prepare the Carrots. Wash, peel, and cut the carrots into sticks or rounds. Blanch briefly in boiling water for 1–2 minutes if you prefer slightly tender carrots, or leave raw for maximum crunch.
Make the Pickling Brine. In a small saucepan, combine vinegar, water, sugar, and salt. Heat over medium until sugar and salt dissolve. Remove from heat and let it cool slightly.
Pack the Jars. Place carrots, garlic, red pepper flakes, and dill into clean glass jars. Pour the warm brine over the carrots, ensuring they’re fully submerged.
Seal & Chill. Seal the jars with lids and refrigerate. The carrots will be ready to enjoy after at least 2 hours, but the flavor improves after 24 hours.