Do you check official web sites of religions and ideologies before "anti" ones?

Excellent question. While it is necessary to hear to hear all sides, it is always best to go to the horse's mouth. If you were getting to know someone and wanted them as a friend, what if they wanted to find out what you were like? Would you prefer that they ask your enemy about you?

While it is true that religion does have some members who were mistreated, look at their spirit. Is it bitter. Do they prove their claims or direct you to a You tube video of an unshaven guy who is talking in a bitter spirit?

In fact studies have been done, that discount disgruntled ex-members testimony in many cases. Certainly not all cases though.

Proverbs 14:15 says to be very shrewd and not believe all we hear. Even if a member is mistreated, shouldn't he try to communicate with the one who he thinks hurt him, and open a dialogue, rather than to get hurt and fight back? If he thinks the other one is showing a godly spirit, it could be asked if he is as well.

I wasn't aware Jesus, Muhammad, and Buddha ran their own websites.

But at any rate, that's generally not how you investigate sales pitches. You don't listen to 2 opposing opinions and try to guess who's lying more.

You investigate the claims objectively. Like Consumer Reports does with products. Or the way a court investigates a legal case.

If a religion claims something, then you look for evidence which supports that claim.

Pick a religion.

The people under that religion are arguing about finer details, any claim of "official" website simply leads to the no true Scotsman fallacy.

I don't study religious websites most of the time. I find they are littered with theological errors and paint a very distorted and false view of God and of what God demands from us.

Usually, yes.

yes, I do because as a Catholic I know that anti groups often misrepresent groups that are not their own