Moz Q&A is closed.
After more than 13 years, and tens of thousands of questions, Moz Q&A closed on 12th December 2024. Whilst we’re not completely removing the content - many posts will still be possible to view - we have locked both new posts and new replies. More details here.
How important is the file extension in the URL for images?
-
I know that descriptive image file names are important for SEO. But how important is it to include .png, .jpg, .gif (or whatever file extension) in the url path? i.e. https://example.com/images/golden-retriever vs. https://example.com/images/golden-retriever.jpg
Furthermore, since you can set the filename in the Content-Disposition response header, is there any need to include the descriptive filename in the URL path?
Since I'm pulling most of our images from a database, it'd be much simpler to not care about simulating a filename, and just reference an image id in my templates.
Example:
1. Browser requests GET /images/123456
2. Server responds with image setting both Content-Disposition, and Link (canonical) headersContent-Disposition: inline; filename="golden-retriever"
Link: <https: 123456="" example.com="" images="">; rel="canonical"</https:> -
In theory, there should be no difference - the canonical header should mean that Google treats the inclusion of /images/123456 as exactly the same as including /images/golden-retriever.
It is slightly messier so I think that if it was easy, I'd go down the route of only ever using the /golden-retriever version - but if that's difficult, this is theoretically the same so should be fine.
-
@Will Thank you so much for this response. Very helpful.
"If you can't always refer to the image by its keyword-rich filename"...
If I'm already including the canonical link header on the image, and am able to serve from both /images/123456 and /images/golden-retriever (canonical), is there any benefit to referencing the canonical over the other in my image tags?
-
Hi James. I've responded with what I believe is a correct answer to MarathonRunner's question. There are a few inaccuracies in your responses to this thread - as pointed out by others below - please can you target your future responses to areas where you are confident that you are correct and helpful? Many thanks.
-
@MarathonRunner - you are correct in your inline responses - it's totally valid to serve an image (or other filetype) without an extension, with its type identified by the Content-Type. Sorry that you've had a less-than-helpful experience here so far.
To answer your original questions:
- From an SEO perspective, there is no need that I know of for your images to have a file extension - the content type should be fine
- However - I have no reason to think that a filename in the Content-Disposition header will be recognised as a ranking signal - what you are describing is a rare use-case and I haven't seen any evidence that it would be recognised by the search engines as being the "real" filename
If you can't always refer to the image by its keyword-rich filename, then could you:
- Serve it as you propose (though without the Content-Disposition filename)
- Serve a rel="canonical" link to a keyword-rich filename (https://example.com/images/golden-retriever in your example)
- Also serve the image on that URL
This only helps if you are able to serve the image on the /images/golden-retriever path, but need to have it available at /images/123456 for inclusion in your own HTML templates.
I hope that helps.
-
If you really did your research you would have noticed the header image is not using an extension.
-
Again, you're mistaken. The Content-Type response header tells the browser what type of file the resource is (mime type). This is _completely different _from the file extension in URL paths.
In fact, on the web all the file extensions are faked through the URL path. For example, this page's URL path is:
https://moz.com/community/q/how-important-is-the-file-extension-in-the-url-for-images
It's not
https://moz.com/community/q/how-important-is-the-file-extension-in-the-url-for-images.html
How does the browser know the the page is an html doc? Because of the Content-Type response header. The faked "extension" in the URL path, is unnecessary.
You can view http response headers for any URL using this tool.
-
-
Do you need a new keyboard?
-
@James Wolff: I'm really hoping you're being sarcastic here. As it's totally fine to serve it without the extension. There are many more ways for a crawler to understand what type a file is. Including what @MarathonRunner is talking about here.
-
This isn't accurate. File extension (in the url path) is not the same as the **Content-Type **response header. Browsers respect the response header Content-Type over whatever extension I use in the path.
Example: try serving a file /golden-retriever.png with a content type of image/jpeg. Your browser will understand the file as a .jpg. If you attempt to save, your browser will correct to golden-retriever.jpg.
You can route URLs however you want.
Additionally, I'm not aware of any way browsers "leverage cache by content type". Browsers handle cache by the etag/expires header.
Got a burning SEO question?
Subscribe to Moz Pro to gain full access to Q&A, answer questions, and ask your own.
Browse Questions
Explore more categories
-
Moz Tools
Chat with the community about the Moz tools.
-
SEO Tactics
Discuss the SEO process with fellow marketers
-
Community
Discuss industry events, jobs, and news!
-
Digital Marketing
Chat about tactics outside of SEO
-
Research & Trends
Dive into research and trends in the search industry.
-
Support
Connect on product support and feature requests.
Related Questions
-
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?
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
Intermediate & Advanced SEO | | Malika11 -
Duplicate URLs ending with #!
Hi guys, Does anyone know why a site can contain duplicate URLs ending with hastag & exclamation mark e.g. https://site.com.au/#! We are finding a lot of these URLs (as duplicates) and i was wondering what they are from developer standpoint? And do you think it's worth the time and effort adding a rel canonical tag or 301 to these URLs eventhough they're not getting indexed by Google? Cheers, Chris
Intermediate & Advanced SEO | | jayoliverwright0 -
Images with a token in the url, in Drupal. How does it affect to SEO?
Hi everyone! I am checking now a website that works with Drupal, and I found that images have urls like this... http://www.brandname.com/sites/default/files/styles/directory_xyz/public/name-of-the-picture.png?itok=T89RpzrK I was wondering how an URL like that with the token at the and, can affect to SEO. I cound't find anything. Anyone knows? Thank you!
Intermediate & Advanced SEO | | teconsite0 -
Linking to URLs With Hash (#) in Them
How does link juice flow when linking to URLs with the hash tag in them? If I link to this page, which generates a pop-over on my homepage that gives info about my special offer, where will the link juice go to? homepage.com/#specialoffer Will the link juice go to the homepage? Will it go nowhere? Will it go to the hash URL above? I'd like to publish an annual/evergreen sort of offer that will generate lots of links. And instead of driving those links to homepage.com/offer, I was hoping to get that link juice to flow to the homepage, or maybe even a product page, instead. And just updating the pop over information each year as the offer changes. I've seen competitors do it this way but wanted to see what the community here things in terms of linking to URLs with the hash tag in them. Can also be a use case for using hash tags in URLs for tracking purposes maybe?
Intermediate & Advanced SEO | | MiguelSalcido0 -
Best way to noindex an image?
Hi all, A client wanted a few pages noindexed, which was no problem using the meta robots noindex tag. However they now want associated images removed, some of which still appear on pages that they still want indexed. I added the images to their robots.txt file a few weeks ago (probably over a month ago actually) but they're all still showing when you do an image search. What's the best way to noindex them for good, and how do I go about implementing it? Many thanks, Steve
Intermediate & Advanced SEO | | steviephil0 -
301 redirect with /? in URL
For a Wordpress site that has the ending / in the URL with a ? after it... how can you do a 301 redirect to strip off anything after the / For example how to take this URL domain.com/article-name/?utm_source=feedburner and 301 to this URL domain.com/article-name/ Thank you for the help
Intermediate & Advanced SEO | | COEDMediaGroup0 -
Export Website into XML File
Hi, I am having an agency optimize the content on my sites. I need to create XML Schema before I export the content into XML. What is best way to export content including meta tags for an entire site along with the steps on how to?
Intermediate & Advanced SEO | | Melia0