There’s a subset of JLCPCB’s parts that they call Basic parts. All other parts they support are called Extended parts. Basic components have a cost per unit. For each type of Extended component you use, JLCPCB adds $3 to your total cost. If you aren’t careful, this can really add up. For example, if your board needs 10 different types of resistors, and you choose Extended components for these, then you’ll end up paying $30 in fees on top of your per-component and assembly costs.
I found the best way to make sure I was choosing Basic parts was to use JLCPCB’s parts page instead of trying to do it entirely through the Library. In EasyEDA’s Library pane, you can filter for
JLCPCB Assembled components, and sort by the
SMT Type column, but I found that this was sometimes out of sync with JLCPCB’s parts database, so you may not find parts that JLCPCB actually has, or they may tell you something is Extended when it’s actually Basic. To avoid that, just go to the JLCPCB parts page and browse or search for what you’re looking for, then filter for