Alt attribute keywords density doesn't matter. You can put as much as you can.

Its for the content not image alt attribute.

Yes, if you're using same keywords as ALT tags in all images than it may cause keyword absuing.

Honestly, I think you may still be reading some outdated guides on SEO. People spend too much time agonising over things like keyword density these days, Google has moved on a LOT in the last 3-4 years and the classic use of "keywords" is not such a major factor these days, much more importance is "relevance", "authority" etc. etc. But if I was choosing where to put which keywords, yes, better avoid overdoing it and putting the keywords everywhere. Since the various "animal" updates it seems highly likely this kind of contrived use of keywords has been a warning flag to Google. Just write keywords "naturally", it's your best bet.

I ran my software against an example keyword "Gift Baskets". It visited the top 100 results and measured over 300 different SEO factors and correlated them against rank position. Here is what I found:

Here are the correlations for having images on page. While having images with alt text does appear to help rankings. Having keywords in those alt texts did not correlate with rank position.

NOTE: Right click and open image in a new tab to see larger.



Having a match in your domain does still appear to matter a little:



Google appears to be wired to favor plus ones. I guess desperate times call for desperate measures.



Who says keyword stuffing doesn't work. :-)



Google's AI still can't figure this one out.



Things not strings has some truth to it too.



And yes you still want your target term to be the most dense word on the page.



Here are the other strong correlations for the search term:



I know people will disagree with me, but until the data tells a different story I am going with the data.

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