[jadc]

This is a very difficult question for anyone to answer for you. It all depends on which metrics/values are most important to you. Here are a few generic ideas:

You can look on Glassdoor for company reviews but they tend to be biased negatively, as in disgruntled people are more likely to write and complain about their experiences than those who are perfectly happy.

Talk to people at both companies, preferably ones in similar positions or doing similar work.

In terms of salary, don't fixate on just the salary but consider total compensation as in salary + stock options + rsu + bonus, etc...

Finally given that you've presumably interviewed with teams at both companies, you should have a better sense about your would-be teammates and manager and which environment suits you better.