Is alcohol-free beer good for you?

"Good for you" is doing a lot of work in that question, so let's be precise: alcohol-free beer is not a health drink, but swapping it in for regular beer removes the specific harms that come from alcohol itself - the calories from alcohol (roughly 7 kcal per gram, with nothing else to show for it), the strain on your liver, the disrupted sleep, and the next-day effects.

What is left is still beer: it can contain calories from malt sugars, and some brands add sugar back in during production to compensate for flavour lost when the alcohol is stripped out. It is not calorie-free or sugar-free by default - check the label rather than assuming "alcohol-free" means "diet drink."

The honest summary: it is a genuinely lower-harm choice than drinking alcohol, but "not as bad as beer" and "good for you" are different claims. Treat it the same way you would treat any soft drink - fine in moderation, worth checking the nutrition panel if that matters to you.