[lougramm]

How can i know missing alt tag ?

[SEO]

 You can know it. There are 2 ways to find the missing alt tags on your website/-s:

1^st way: manually,
2^nd way: by tool.

If you choose manual method to find missing alt tags, then firstly you have to open the website and press "Ctrl + U", then page of view-source will be open. You can open it in another way, too, but it's not the point here. After that, press "Ctrl + F" the find box will be open (there is another way about it, too, but it's also not the point here), and type "alt="here type your keyword/-s". If the alt tag is missing it will show "alt="", this type of syntax.

And about the second method -- you can use some of the popular tools for instant search. There are so many tools available nowadays.

Hope it answers well your alt tag question.

[MSL]

  Checking alt tags is important. Thus this topic is very good and useful. Thanks a lot!

[jackluter]

Yes, there are more tools available in the search results. contentforest is thew best one

[johnniewalk]

Just check your website by using a on page checker tool it display your missing alt tag, but am not sure it will display all the missing alt tag but almost missing one.