I'm using a custom tooltip library, to view my titles and image alts. The way an image or link is rendered without this script is:

<img src="URL HERE" title="TITLE HERE" height="123" width="321">

As you see the title is there. But after rendering the page while having the script enabled, the above image will be rendered as:

<img src="URL HERE" class="CUSTOM TOOLTIP" height="123" width="321">

The alt is gone (or the title, if it's a link tag), and it's replaced by the custom class. When you hover it, you can see the proper title/alt.

The HTML output is changed in the console, but not in the source output (obviously because jScript is client side).

Now the question is, can search engines still read the alt/title attributes?

I've read that nowadays google renders your page with JavaScript enabled, so i'm not sure if it takes this into account.

2 Answers 2


As mentioned, there is no evidence that title attributes on HTML elements are used by Google for ranking purposes - this is correct.

The previous answer cites an irrelevant Tweet but does provide some value because the Googler explicitly advises testing. I'd urge you to discard the source citation and the statement by Simon which states that "It's unlikely that Google or Bing actively monitors the DOM for Title Changes"

This is beyond easy to test especially since you're developing in jScript. Google does in fact wait for DOM mutations - and multiple tests suggest that they wait up to 5 seconds - here's a simple test where the DOM was manipulated and Google's fectch and render service in Google search console did in fact wait for 5 seconds.

dom mutation by intervals There's also a full post of JS tests that also confirm this : http://searchengineland.com/tested-googlebot-crawls-javascript-heres-learned-220157. If we can inject links, metadata, change HTML and Google accounts for DOM changes, there's no reason why they wouldn't be able to pick up title attribute changes. Bottom line, test it - this test should take 5 minutes and you'll get confirmation.


Title does not improve SEO rankings

There is no evidence to support that Google or Bing's Algorithm consider title attributes in both <img> or <a> elements. Title is considered an attribute that improves the user experience of a site and not the SEO. You images should always have ALT tags for SEO purposes as this is apart of their Algorithm.

It's unlikely that Google or Bing actively monitors the DOM for Title Changes

In regards of Google having the ability to monitor changes to the title tag its unlikely because its not something that should occur, unless the image changes because a title generally shouldn't need to change, same goes to ALT tags.

John Muller from Google tweeted this tweet awhile back:


@dawnieando If you're changing the title with onmouseover, I doubt we'd pick that up. If it's just the title attribute: maybe. Test & tell?

If its for ranking purposes use something other than title

If your doing it for caption purposes then you should substitute title for a real container, such as <div>, <aside> or even <figcaption>, that way Google and other search engines will take the content into consideration, since title is not considered content but for improving UX (User Experience).

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