Answer
The better option depends on your basket and delivery charge. Compare the final payable total after each eligible promotion rather than choosing only by the headline offer.
A percentage code can save more on a high-value basket, while free delivery can be better on a smaller order. Minimum spend, excluded items and delivery method can change the result.
What to check before checkout
Read the retailer’s current promotion terms, confirm that the code applies to the items in your basket, and make sure the expected saving appears before you pay.