If Robots.txt have blocked an Image (Image URL) but the other page which can be indexed has this image, how is the image treated?

[Malika1]

Hi MOZers,

This probably is a dumb question but I have a case where the robots.tags has an image url blocked but this image is used on a page (lets call it Page A) which can be indexed. If the image on Page A has an Alt tags, then how is this information digested by crawlers?

A) would Google totally ignore the image and the ALT tags information? OR

B) Google would consider the ALT tags information?

I am asking this because all the images on the website are blocked by robots.txt at the moment but I would really like website crawlers to crawl the alt tags information. Chances are that I will ask the webmaster to allow indexing of images too but I would like to understand what's happening currently.

Looking forward to all your responses

Malika

[alphonseha]

May I ask why you/your webmaster would have noindexed your images in the first place?

[Malika1]

Hi donford,

Thanks for this detailed answer, really appreciate it!

Malika

[donford]

Hi Malika,

Blocking image directories or images themselves in robots.txt only prevents the image from being added to "image" search results. You will still get the full benefit of the alt text on the page, the image just won't appear in the image results.

How this actually works is the crawler will crawl the site and index all the text and weight (h1, h2, alt etc..) then when the crawler moves to add the image to the search cache it finds it can't access it due to robots.txt and simply ignores it and goes on.This leaves your original text as what is indexed as a search result, and nothing for image results.

If you are using Apache you may want to not use robots.txt as the method of blocking images. I would recommend using the .htaccess file with a code like this...

<filesmatch ".(bmp|gif|jpg|png|tif)$"="">Header set X-Robots-Tag "noindex"</filesmatch>

This is a blanket declaration and would prevent indexing of any images with the noted extensions on your site. This is particularly useful if you have multiple image directories. Further more if there are a few images you want indexed you could pick a particular extension like .jpeg for example (note jpeg not jpg), then just convert those few images and know they will be indexed as they are not in the exclusion list.

Another benefit of handling it this way is if you already have images that are indexed, using the noindex tag will get them out out of the image directory much faster than blocking them. The reason is you are giving Google a new directive which is "noindex", otherwise they will just treat them as inaccessible and move on, leaving any cached version to appear in the directory for some time.

Hope that makes sense and helps,

Don