Global Entry vs TSA PreCheck vs CLEAR
What each one does
TSA PreCheck gives you a faster domestic security lane (shoes and laptops stay packed). Global Entry includes PreCheck and adds expedited U.S. customs and immigration when you fly back into the country, so it is the better buy if you travel abroad at all. CLEAR is different: it uses your eyes or fingerprints to verify identity and move you to the front of the line, then you still go through PreCheck or standard screening.
Which to get
For most travelers, Global Entry is the winner, since it costs only slightly more than PreCheck and includes it while adding customs speed. CLEAR is a separate paid membership that can stack with PreCheck for the fastest experience, but it is pricier and not at every airport. Many people get Global Entry plus CLEAR; PreCheck alone suits purely domestic flyers.
Let a card pay for it
Many travel cards reimburse the Global Entry or TSA PreCheck application fee (usually once every four years) as a statement credit, and some premium cards now credit a CLEAR membership too. If your card offers it, the enrollment is effectively free. See the Global Entry credit and premium travel cards.