Local
Shanghai SEG Electronics Market
Online
NeoPixels etc. https://shop123784690.taobao.com/
EL Wire etc. https://shop214953723.taobao.com/ https://shop114533919.taobao.com/
DF Robot (local) https://dfrobot.taobao.com/
RISYM https://risym.tmall.com/
DIY More https://diymore.world.tmall.com/
YW Robotics https://ywrobot.taobao.com/
Mechanisms: https://shop103286948.taobao.com/
CNC Mechanisms: https://shop65654750.taobao.com/
International Online
McMaster Carr https://www.mcmaster.com/
Pololu https://www.pololu.com/
RobotShop https://www.robotshop.com/
ServoCity https://www.servocity.com/