Optimizing images for search engines has nothing to do with image editing. But why should you optimize images at all? Quite simply: We all love pictures. Images animate us to click. So if you manage to reach one of the top positions in Google Image Search, you can increase the traffic on your website and in the best case achieve a better conversion rate.
Optimize images = readability for Google & Co.
Unfortunately, web content often unknowingly ignores the fact that Google and Co. are still text-based search engines for the most part. Accordingly, images must be provided with information in text form so that the bots of the search engines can correctly index the images and assess their relevance for certain keywords.
But how do you provide visual information in text form to the search engines? Is it necessary to retell the content of the image? In principle, yes, but you don’t have to add a long text to each image, but can use a number of different elements and attributes that together make the image content comprehensible to search engines:
– title tag
– surrounding text
– Heading of the paragraph in which the image is located
File name – orientate on the main keyword
The image name is probably the most important attribute. It is the first indication that Google confirms the affiliation to the content of the respective page. If, for example, the home page of a locksmith shows the locksmith car and the image is named “dcim-02456.jpg”, the page content and image content do not match in textual terms. Consequently, this picture will not reach a good position for the search phrase “locksmith_brandname-car”. Therefore it is even more important that the picture name is provided with the main keyword of the respective page. So if the URL of the picture should rank to “Honeymoon Maldives”, the picture must be named exactly the same on the corresponding page: Honeymoon_Maldives.jpg
If you come from Europe and write in a language that uses special words like “ä”, “ü” or “ß” – you should pay attention to the following information:
Only lower case letters should be used for picture names and special characters, umlauts and “ß” should be avoided. These can be processed correctly by very few browsers, which is why they have often changed automatically. As a result, the target URL and image name are falsified – in the worst case, this can even result in error messages.
If several images are used on one page, they should also be provided with appropriate keywords. A thorough keyword analysis is advantageous here, which – sorted by keyword clusters – enables a quick assignment of suitable image names. If there are many similar keywords (e.g. singular/plural), even the least similar keywords can be used to avoid overlapping and thus indexing problems.
Image 1: honemoon-mauritius.jpg
Image 2: honeymoon-mauritius-or-bali.jpg
Image 3: honeymoon-where-to-go.jpg
Only hyphens should be used as word separators since underscores are considered to be a connecting element. Thus “honeymoon_maldives.jpg” would be read as “honeymoonmaldives”. A disadvantage with older picture names with underscore does not result from it however provably. Factors like quality and actuality of the site play a much bigger role.
Title-tag: Store extended image information for users and robots
In addition to the image name, the title tag is also included in the image SEO. This tag can be used to provide additional information about the image and page content. The HTML code then looks like this:
<img src=”folder/honeymoon-maldives.jpg” title=”Honeymoon in Maldives”/>
The title tag should always be present. If image names are generated automatically and keywords do not appear in the image name, this guarantees comprehensible information for Google. In this case, the single keyword can be used as an image title to increase the value for Google.
Alt-tag: Use emergency day for SEO
The alt tag is essential when it comes to image SEO. It guarantees that there is at least a descriptive text if the image cannot be displayed in the browser. Usually, this is the name of the image, combined with a short description of the image content. Here you can also revert to normal spelling since no links or graphic addresses depend on the name. The HTML code with alt-tag and title-tag could then be as follows:
<img src=” folder / honeymoon-maldives.jpg” title=”Honeymoon in Maldives” alt=”Honeymoon Maldives”/>
As a visible element for the visitor, the caption also passes on additional image information to Google – either on the image content, the text context, or the copyright. Here, too, the use of a keyword is, of course, a good idea to make it easier for Google to relate to the text.
- Example 1: Honeymoon Center New York ©photostock
- Example 2: At Honeymoon4ever you’re able to book an unforgettable honeymoon that you’ve never experienced before.
The caption also represents the text closest to the image, which in turn influences the relevance rating by Google.
Text surrounding the image – must remain within the topic
Also, the continuous text around the picture and the heading of the paragraph should not be underestimated in its importance. If the previously observed notes fit the content of the text and the rest of the page, there is hardly anything standing in the way of a good picture ranking.
If the two differ from each other, for example, because the text refers to the advantages of the service of a locksmith in New York City, but the picture uses keywords to indicate the purchase of sports bows, the strategy should be reconsidered. An image that does not match the text meaningfully should, therefore, be replaced.
Incidentally, this also makes sense from the user’s point of view, as the reader can see at first glance that he has landed on the right page.
Images used on a product page, for example, should be optimized according to the product. If the same images also appear on the home page or in a blog post, these versions should be optimized according to the respective page theme. However, individual images for each page are preferable, as this has a more serious effect on the visitor and demonstrates individuality.
Technical image optimization for SEOs
In addition to the content aspects of search engine oriented image optimization, technical aspects also play a role. Depending on image size, file formats and the number of images appearing on a page, the loading time of a domain can and should be as short as possible. The overall performance of a domain has a direct impact on the user experience and both page speed and user signals are now considered ranking factors.
- Save images and logos as .jpg, .gif, .tif, .png or .svg if possible; these formats require only a few kB of memory, depending on the resolution and pixel size of the image.
- An acceptable resolution for web images is 72-150 ppi. If the image has a lower resolution from the beginning, it should be kept, otherwise, the image will be blurred. On the other hand, if the resolution is too high, the image will be “pixelated” when you resize it.
- The number and size of the images should be chosen according to the text length. Many images in combination with only little text indicate weak content (photo series/pages excluded, of course) such pages quickly become superfluous.
- The actuality of the images is also an indication of whether a page is maintained regularly or not. If neither text nor images are regularly updated or new content is created with new images, Google interprets this as less valuable compared to pages that regularly come up with new material.A little trick: Long-term existing content can be upgraded e.g. with new or additional image material.
Conclusion: Topic-relevant attributes for good image ranking
With appropriate maintenance of all attributes and the technical characteristics of an image, it can achieve top positions in Google Image Search. It is true that motif, image statement, and aesthetic quality are of secondary importance for Google & Co. But accurate, up-to-date, and appealing image material has a positive effect on user behavior. Attractive image material in web-friendly formats with topic-relevant attributes are therefore the criteria with which a domain becomes attractive both for the user and for Google.