Do I need a new key fob or just programming?
Short answerReplacement is the physical fob. Programming is the step where the car learns to recognize it. A missing or destroyed fob needs hardware. A compatible fob you already have may only need programming. A random fob that looks similar is not automatically programmable.
Replacement
The fob is gone, cracked, water-dead, or the buttons do nothing because the board is finished. You need a unit the car can actually use. Looks-like-mine is not a spec. Year, make and model decide which part family even belongs on the car.
Programming
The car has an immobilizer: electronics that refuse to start unless they see an approved chip or fob. Programming is registering a credential with that system. It is not “pressing lock a few times and hoping,” and it is not something we will write as a DIY sequence on this site.
When you already have a fob
If you have a fob that was made for that vehicle family — including some unused aftermarket units that actually match — programming may be the missing piece. If you have a used fob from another car, read the used-fob guide before you assume it will pair.
Compatibility in ordinary language
Fobs have identifiers so the remote and the car speak the same radio language. People call this FCC ID or part number. You do not need to memorize the codes. You do need the vehicle details so we are not guessing from a three-button photo. The wrong ID can look right in a listing and still never pair.
What to send
Year, make, model, whether the car is push-button, and whether you already have a fob in hand. That is enough to start a price conversation. Do not buy a marketplace fob first and treat programming as a cleanup step.