<b>"Trailing slashes and www vs non-www tank your SEO."</b>

<b>"Trailing slashes and www vs non-www tank your SEO."</b>

They don't tank anything. Inconsistency does, mildly, and only if you ignore it.

Here's the real picture. /page and /page/ are technically different URLs and can serve duplicate content. www and non-www are different hostnames. None of this carries a penalty. Google handles both, picks a canonical, and moves on.

The actual cost shows up when you're sloppy: half your internal links go to /page, half to /page/, each version accumulates separate link signals, and you've split your own authority across two addresses for no reason. Same story if both www and non-www resolve with 200s and no redirect.

The fix is one-time and permanent: pick a format, 301 the other to it, make every internal link use the chosen version, set the canonical to match. Then never think about it again.

This isn't an optimization. It's hygiene. The penalty isn't from Google — it's from you diluting yourself.

(If both versions return 200 and you've "never had a problem," you've had a quiet problem the whole time.)