One thing Google does in the search results that tends to annoy site owners is when Google will rewrite a carefully crafted title tag with one of their own, sometimes with mixed results and effectiveness.  And these titles can vary significantly based on the query – a single search result could have dozens of different title tags showing in the search results.

Google has said previously that they rewrite titles because when they experiment with it, searchers preferred the rewritten titles over the ones the site owners had chosen.  And some of these titles are definitely worthy of being rewritten, such as those with “Homepage” or the ones that simply have “Company Name” on every page of a site.

And titles can also be influenced with third party factors, such as anchor text from an external site.  However, this is most often seen on pages that are indexed but blocked from being crawled by Googlebot, so Google has to use outside factors in an attempt to come up with a title.

At State of Search last week, I asked Gary Illyes about Google rewriting title tags, and he added a bit more about why Google does this.

So the title tag is query dependent. Basically what we are trying to do is ensure that people will click through the results. We see lots of bad title tags [me: like homepage] yes and untitled for example, and I know for sure that this is actually a good thing, even if people don’t like it.

So the fact Google is also doing this to entourage click throughs is an interesting perspective.  After all, Google wants searchers to find what they are looking for, and oftentimes, rewritten title tags can better reflect the content on the page with the actual search query used.

If you are unhappy about any rewritten titles going is doing, searchers do have the option of leaving feedback from the search results page.