How To Find Missing Image Alt Text & Attributes

How To View Alt Text & Find Missing Alt Text

Image alt text (alternative text) is used within the HTML of a website to describe an image, principally for web accessibility (for blind and visually impaired) or if the image cannot be displayed for some reason, as the text will appear in place of the image. It’s also used to by search engines to understand the content of the image.

Image alt attributes (often referred to incorrectly as ‘alt tags’) should specify relevant and descriptive alternative text about the purpose of an image and appear in the source of the HTML like the below example.

<img src="screamingfrog-logo.jpg" alt="Screaming Frog" />

The alt attribute itself and/or the alt text are often forgotten entirely and tracking them down can be a labourious task without automated tools.

You can use the Screaming Frog SEO Spider tool for free (and paid) to view your image alt text and find missing alt attributes and alt text on your website. Below is a very quick and easy tutorial on how to check alt text of images, find missing alt text or tags, large images and bulk export them.

First of all, you’ll need to download the Screaming Frog SEO Spider which is free in lite form, for crawling up to 500 URLs. You can download via the buttons in the right hand side bar.

The next steps to find missing alt text within your website can be viewed in our video, and tutorial below.

1) Crawl The Website

Open up the SEO Spider, type or copy in the website you wish to crawl in the ‘enter url to spider’ box and hit ‘Start’.

2) Click On The ‘Images’ Tab

Next up, click on the ‘images’ tab, where you will see the URLs of all images discovered during the crawl, the size of the image, and the number of source IMG inlinks.

3) Click On An Image, Then Click The ‘Image Details’ Tab At The Bottom

The ‘Image Details’ tab at the bottom of the SEO Spider will populate the lower window pane with information on the source pages that reference the image (the ‘from’ URL) and the alt text of every image element discovered.

It will also display the image selected on the right-hand side.

In the example above, you can see that four pages on our website (the ‘From’ addresses) have an image of Rand Fishkin (https://www.screamingfrog.co.uk/wp-content/uploads/2014/03/rand.jpg) with different alt text. One has ‘rand’ as the alt text, the others are blank, meaning they are missing alt text.

Images can have many different URLs referencing them, and hence, many different alt texts. While many CMS set a single alt text for any image, it’s actually set in the HTML within the IMG element and alt attribute, which like anchor text of a link, can be very different.

Hence, image alt text cannot be simply set in a single column next to an image and this is why our multi window approach allows users to review every alt text for consistency.

4) Use The Filter To Select ‘Missing Alt Text’ & ‘Missing Alt Attribute’

The filters refine URLs within the ‘Images’ tab to display images which have ‘Missing Alt Text’, or ‘Missing Alt Attribute’.

The ‘Missing Alt Text’ filter includes images that have an alt attribute, but it’s empty or has whitespace.

<img src="screamingfrog-logo.jpg" alt="" />

The ‘Missing Alt Attribute’ filter includes images that do not have an alt attribute.

<img src="screamingfrog-logo.jpg" />

It’s useful to split these out into separate filters, as decorative images should have empty alt text, rather than leaving out the alt attribute – which can cause issues in screen readers. However, in reality we often see decorative images without alt attributes as well.

Where possible, decorative images should be provided using CSS background images. Check out the W3C alt decision tree for advice on what alt text should be included for different types of images.

5) Bulk Export Missing Alt Text & Source Pages Via ‘Bulk Export > Images > Images Missing Alt Attribute & Text’

You can simply use the ‘export’ button on the ‘Images’ tab with the filter set to ‘Missing Alt Text’ or ‘Missing Alt Attribute’ to just export that view of the images only.

However, if you want to bulk export all source pages that reference images that are missing alt text, alt attributes or both together (and the blank alt text columns) then use the bulk export menu.

This will allow you to see source pages, the image URL and alt text.

6) Bulk Export All Image Alt Text Via ‘Bulk Export > Images > All Images’

This bulk export will include all source pages referencing images and their respective alt text (including those which are missing).

If All Images Are Not Being Found

Occasionally you may find that some images on a website are not discovered, and there are two common reasons for this.

The images are loaded using JavaScript or CSS (like CSS ‘background-image’). If this is the case, then simply switch to JavaScript rendering to crawl the site and discover all these images. Remember to ensure JS and CSS files are not blocked.
The images are blocked by robots.txt. You can either ignore robots.txt or customise the robots.txt to allow crawling.

Hopefully the above guide helps illustrate how to use the SEO Spider tool to check for missing alt text efficiently.

Please also read our Screaming Frog SEO spider FAQs and full user guide for more information