Cut fresh watermelon into cubes, removing any seeds. If using frozen watermelon, ensure it's fully thawed before blending.

Place the watermelon cubes into a blender or food processor and add lime juice, vanilla extract, and a pinch of salt.

Blend the mixture until smooth, scraping down the sides if necessary to ensure all pieces are fully incorporated.

Pour the blended mixture into a shallow, freezer-safe container and spread evenly.

Cover the container and freeze for 2-4 hours, stirring every 30 minutes to prevent ice crystals from forming and to achieve a smooth texture.

Once the sorbet is firm and scoopable, serve immediately or store in an airtight container in the freezer for up to 1 week.