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
-
Mass URL changes and redirecting those old URLS to the new. What is SEO Risk and best practices?
Hello good people of the MOZ community, I am looking to do a mass edit of URLS on content pages within our sites. The way these were initially setup was to be unique by having the date in the URL which was a few years ago and can make evergreen content now seem dated. The new URLS would follow a better folder path style naming convention and would be way better URLS overall. Some examples of the **old **URLS would be https://www.inlineskates.com/Buying-Guide-for-Inline-Skates/buying-guide-9-17-2012,default,pg.html
Intermediate & Advanced SEO | | kirin44355
https://www.inlineskates.com/Buying-Guide-for-Kids-Inline-Skates/buying-guide-11-13-2012,default,pg.html
https://www.inlineskates.com/Buying-Guide-for-Inline-Hockey-Skates/buying-guide-9-3-2012,default,pg.html
https://www.inlineskates.com/Buying-Guide-for-Aggressive-Skates/buying-guide-7-19-2012,default,pg.html The new URLS would look like this which would be a great improvement https://www.inlineskates.com/Learn/Buying-Guide-for-Inline-Skates,default,pg.html
https://www.inlineskates.com/Learn/Buying-Guide-for-Kids-Inline-Skates,default,pg.html
https://www.inlineskates.com/Learn/Buying-Guide-for-Inline-Hockey-Skates,default,pg.html
https://www.inlineskates.com/Learn/Buying-Guide-for-Aggressive-Skates,default,pg.html My worry is that we do rank fairly well organically for some of the content and don't want to anger the google machine. The way I would be doing the process would be to edit the URLS to the new layout, then do the redirect for them and push live. Is there a great SEO risk to doing this?
Is there a way to do a mass "Fetch as googlebot" to reindex these if I do say 50 a day? I only see the ability to do 1 URL at a time in the webmaster backend.
Is there anything else I am missing? I believe this change would overall be good in the long run but do not want to take a huge hit initially by doing something incorrectly. This would be done on 5- to a couple hundred links across various sites I manage. Thanks in advance,
Chris Gorski0 -
Large robots.txt file
We're looking at potentially creating a robots.txt with 1450 lines in it. This will remove 100k+ pages from the crawl that are all old pages (I know, the ideal would be to delete/noindex but not viable unfortunately) Now the issue i'm thinking is that a large robots.txt will either stop the robots.txt from being followed or will slow our crawl rate down. Does anybody have any experience with a robots.txt of that size?
Intermediate & Advanced SEO | | ThomasHarvey0 -
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 -
Image URLs - best practice
Hi - I'm assuming image URL best practice follows same principles as non image URLs (not too many files and so on) - I notice alot of web devs putting photos in subdomains, so wonder if I'm missing something (I usually avoid subdomains like the plague)!
Intermediate & Advanced SEO | | McTaggart1 -
How important is admin-ajax.php?
Hi there! It's been a long time since I last did a technical audit of a site. I've currently playing with the 'fetch as google' tool to find out if we're blocking anything vital. The site is based on Wordpress, and after a recent hacking incident, a previous SEO moved the login portal from domain.com/wp-admin/ to domain.com/pr3ss/wp-admin/ - to stop people finding it. Fair enough. But they then updated the robots.txt file to look like this: User-agent: *
Intermediate & Advanced SEO | | Muhammad-Isap
Disallow: /pr3ss/wp-admin/ Now, some pages are trying to draw on theme elements like: http://www.domain.com/pr3ss/wp-admin/admin-ajax.php
http://www.domain.com/pr3ss/wp-content/themes/bestpracticegroup/images/column_wrapper_bg.png And are naturally being blocked (not that this seems to affect the way pages are rendering in Google's eyes) A good SEO friend of mine has suggested allowing the theme folder, and any sub folders where this becomes an issue. What are your thoughts? Is it even worth disallowing the /pr3ss/wp-admin/ path? Cheers guys and gals! All the best, John. I've found a couple of the theme's0 -
Canonical URL & sitemap URL mismatch
Hi We're running a Magento store which doesn't have too much stock rotation. We've implemented a plugin that will allow us to give products custom canonical URLs (basically including the category slug, which is not possible through vanilla Magento). The sitemap feature doesn't pick up on these URLs, so we're submitting URLs to Google that are available and will serve content, but actually point to a longer URL via a canonical meta tag. The content is available at each URL and is near identical (all apart from the breadcrumbs) All instances of the page point to the same canonical URL We are using the longer URL in our internal architecture/link building to show this preference My questions are; Will this harm our visibility? Aside from editing the sitemap, are there any other signals we could give Google? Thanks
Intermediate & Advanced SEO | | tomcraig860 -
Creative Commons Images Good for SEO?
I've been looking at large image packages through iStock, Getty, Fotolia and 123RF, but before spending a bunch of money, I wanted to get some of your feedback on Creative Commons images. Should be worried that something found on Google Images > Search Tools > Usage Rights section can be used without issue or legal threats from the big image companies so long as they are appropriately referenced? AND will using these types of images and linking to the sources have any affect on SEO efforts or make the blog/website look spammy in Google's eyes because we need to link to the source? How are you using Creative Commons images and is there anything I should be aware of in the process of searching, saving, using, referencing, etc? Patrick
Intermediate & Advanced SEO | | WhiteboardCreations0 -
How to See Image Metadata?
We sell 1000s of audiobooks and get our cover images and descriptions from the publisher’s sites. When I download a cover image such as this one (http://www.audiobooksonline.com/media/Alex-Cross-Run-James-Patterson.jpg)
Intermediate & Advanced SEO | | lbohen
I always rename and re-size it before installing at our Web store. Would this process result in any publisher’s metadata in the image we use at our Web store and/or anything else Google would not like?
Is there an online utility that would allow me to see metadata in our images?0