Chrome vs Chromium


my question is regarding whether chromium browser is sufficient for web mobile testing as Chrome browser is incompatible with android emulators.

i want to automate mobile web on a website which is “designed to work on chrome”.
my options are (in the emulator world):

  1. android emulator - doesn’t support Chrome but Chromium can be installed.
  2. genymotion - support Chrome and All the rest but isn’t free (for non-private use)
  3. real device - not relevant for now

wanting to stay on the FREE side, my concern is how similar Chromium is to Chrome? does they share the same rendering engine? is it the RIGHT thing to do to rely on test automation on Chromium instead of Chrome? which is not the real world target?

would appreciate your opinions here,