1. Decide how much it matters
A recipe tweak and a medication question deserve different effort. The higher the stakes, the more you should verify and the more you should involve a professional.
2. Look for specifics you can test
Names, dates, numbers, quotes and references are the easiest things for a model to get wrong and the easiest for you to check. Pick the two or three the answer depends on and look them up.
3. Ask again, a different way
Rephrase the question, or ask a second model. If the answers differ, find out why before you pick one.
4. Be careful with citations
Models can produce references that look real and aren't. Open every link and confirm the page says what the answer claims.
5. Go to a primary source
For health, law, money and anything official, use the source that's responsible for the facts: the agency, the statute, the manufacturer, the textbook, or a qualified person.
Where Keplar fits
Keplar does step 3 for you by asking several models and showing where they differ. It doesn't do steps 4 and 5: it hasn't checked the sources the models cite, and it doesn't browse the web yet.