Should I REALLY keep all my credit cards totally paid off every month?

Every time I search for the question "Should I pay off my credit cards", everyone says "YES! It's great for your credit!" BUT THEN, you run into articles with directly conflicting information like this one from Experian themselves: https://www.experian.com/blogs/ask-experian/is-no-credit-utilization-good-for-credit-scores

This article states "A 0% credit utilization rate has no real benefit for your credit score. Instead of aiming for no utilization, keep your credit utilization rates below 30%, and preferably under 10%, to help your credit."

In other words, DON'T pay off all your credit cards every month. Keep like, 1% utilization or something on all of them.

So which is it? Pay off all your credit cards every month, or keep a tiny balance on them? I don't care about the few dollars of interest or whatever I'll be charged on the 1% balance. Who cares. I care about making my score as high as possible.

Summary: Everyone says "pay your credit cards off", but then you read "Don't have 0% utilization", and these are literally opposite things. What is the correct percent of utilization to keep on your credit cards for the best possible credit score? Is it zero, or non-zero (one percent, two percent, anything below six percent)?

Paying the statement balance each month is not the same as 0% utilization. 0% utilization means that you didn't use the card at all that month, or you made payments to get the balance to zero before the monthly statement was created.

The balance that gets reported to the credit bureaus is typically the statement balance on your card, not the balance after you make a payment. The "utilization" that the credit scorers calculate is therefore based on how much you put on the card over the month, not how much you float from month to month.

The reason to pay at least the statement balance every month is not to build credit, but to avoid paying interest. You get the same benefit to your credit score by making a minimum payment on time, but you'll get charged 2% interest (24% annualized) or more on the remaining balance each month. (It's actually charged on more than the remaining balance, but that's not the point here)

For example, if your credit limit is $10,000 and you want to have a 6% utilization (I'm not saying that's the perfect amount, just an example) then you would try to spend about $600 each month and pay it off each month.

I would also note that your payment history is generally a bigger factor than utilization. Utilization is more to measure if you're using too much credit, or have too much to use (meaning you could theoretically go on a shopping spree). If you pay your bills each month and don't use too much credit you'll be fine.

Secondly, your credit score is not a measure of how good you are with money. It's a measure of how likely you are to pay off your debts. There is very little benefit to making it "as high as possible" other than personal feelings. My credit score has wavered between 750 and 820 and the variance has had absolutely no impact on my ability to get loans or any other aspect of my life. There are negative consequences for low credit scores if you want to borrow money, but those are because of bad behavior that make you a possible credit risk (trust is hard to earn but easy to lose). The only thing a max credit score gets you is a little more grace if you mess up once.

What is the correct percent of utilization to keep on your credit cards for the best possible credit score? Is it zero, or non-zero (one percent, two percent, anything below six percent)?

It's not zero but no one knows the exact percentage. It may also be the case where the "best" percentage is different depending on other factors.