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.
Sitespeed: Do images require width and height attributes?
-
Currently working on a sitespeed issue, and was wondering if not having width and height for images actually do cause a problem. We simply Photoshop the resolution we require for the image and add it to the page as is. I though this would actually speed it up, but I am getting from www.gtmetrix.com that we should have them.
What's your experience? Thanks!
-
Just came across a terrific resource that reminded me you'd asked about further reading, Ben.
Check out BrowserDiet for a huge collection of resources about tuning front-end performance of websites. (You'll see #6 talks about exactly your original question)
I can also recommend reading Steve Souder's two books - High Performance Websites and Even Faster Websites - both from O'Reilly. Souders is pretty much the leading specialist in this area. He's the creator of YSlow, one of the primary tools for measuring/analyzing site speed, and is now Head Performance Engineer at Google. His website is SteveSouders.com
That'll be more than enough to get you started. Lemme know if you're still hungry for more!
Paul
P.S. The report details from tests at webpagetest.org can also teach you a huge amount, and there's a forum there run by Patrick Meenan (who built webpagetest) which is just excellent. Patrick frequently answers questions personally.
-
you're welcome, hope your site will be speeding up a lot!!!
-
Yes, thank you. We size them all to what we want on the site so we are good there. Just got done doing it, and it did make a difference. Thanks guys!
-
as Paul correctly said, if your purpose is to improve the page speed just be sure that you're not resizing the images with css/html but that you're uploading the images in that dimensions.
An image of 10241024 resized to 100100 still weights as an 1024 image so my recommendation is to resize all those images to the desired dimensions, moreover if you can use an external cdn you'll save bandwith and have those images loading outside your website. That will help reducing the loadtime of the page.
-
Perfect-O! I completely get it now. Thanks Paul. You da man!
I thought it would be faster as in my mind it was more to read, but now that I understand the loading, I get it. Guess I need to start researching how a website loads. Have any resources I can read, to up my experience with this?
I've been in development but on an application side not website side.
-
The main reason PageSpeed and YSlow recommend including width and height for images is as much the perception of page speed as the actual load time, Ben.
When you include the image dimensions, the browser can draw out the "containers" that will hold the images, reserving the space for them while they download. The browser can then go on the paint the rest of the pages CSS and objects around those "containers" without having to go back and redraw the whole page once the images have downloaded and their sizes are then known.
This gives the user the illusion of a much faster, cleaner page load, and hence the impression of a faster website.
Does that make sense?
Paul
[Edited to add: You should still keep doing what you're doing to produce "size-as" images for your pages. You don't want to be resizing images with the html dimensions, just reporting in html the actual size of the image]
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
-
Probably basic, but how to use image Title and Alt Text - and confusing advice from Moz!
I've been doing SEO on my business's site for years and have got good results. I've always used image Titles and Alt Text text. Our blog posts are image-intensive, often with 100-200 pictures (not surprising since we're photographers). For any given blog post, I've tended to have a uniform image Title for each image and then a more specialised Alt Text tag giving a description. A typical image on one of our blog posts would be like this: Image filename: wedding-photography-at-so-and-so-venue-001.jpg .... 002, 003 etc Image Title Attribute: Wedding Photography at So-And-So-Venue by Our-Company-Name - this would be the same for every image in the blog post. Alternative Text: Bride and groom exchanging vows during wedding ceremony at so-and-so-venue - this would be tailed for each image. So my question is - is this right? The Moz help page for image SEO is actually incorrect in one aspect: https://moz.com/ugc/10-tips-for-optimizing-your-images-for-search "Alt text (short for “alternative text”) is used to highlight the identity of an image when you hover over it with your mouse cursor. It also shows as text to all users when there are problems rendering the image." This is not the case. Hovering over the image in Firefox, Chrome, Edge and Opera ALL display the Image Title, NOT Alt Text. Thoughts?
Intermediate & Advanced SEO | | robandsarahgillespie0 -
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
Intermediate & Advanced SEO | | dsbud
2. Server responds with image setting both Content-Disposition, and Link (canonical) headers Content-Disposition: inline; filename="golden-retriever"
Link: <https: 123456="" example.com="" images="">; rel="canonical"</https:>1 -
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 -
Dilemma about "images" folder in robots.txt
Hi, Hope you're doing well. I am sure, you guys must be aware that Google has updated their webmaster technical guidelines saying that users should allow access to their css files and java-scripts file if it's possible. Used to be that Google would render the web pages only text based. Now it claims that it can read the css and java-scripts. According to their own terms, not allowing access to the css files can result in sub-optimal rankings. "Disallowing crawling of Javascript or CSS files in your site’s robots.txt directly harms how well our algorithms render and index your content and can result in suboptimal rankings."http://googlewebmastercentral.blogspot.com/2014/10/updating-our-technical-webmaster.htmlWe have allowed access to our CSS files. and Google bot, is seeing our webapges more like a normal user would do. (tested it in GWT)Anyhow, this is my dilemma. I am sure lot of other users might be facing the same situation. Like any other e commerce companies/websites.. we have lot of images. Used to be that our css files were inside our images folder, so I have allowed access to that. Here's the robots.txt --> http://www.modbargains.com/robots.txtRight now we are blocking images folder, as it is very huge, very heavy, and some of the images are very high res. The reason we are blocking that is because we feel that Google bot might spend almost all of its time trying to crawl that "images" folder only, that it might not have enough time to crawl other important pages. Not to mention, a very heavy server load on Google's and ours. we do have good high quality original pictures. We feel that we are losing potential rankings since we are blocking images. I was thinking to allow ONLY google-image bot, access to it. But I still feel that google might spend lot of time doing that. **I was wondering if Google makes a decision saying, hey let me spend 10 minutes for google image bot, and let me spend 20 minutes for google-mobile bot etc.. or something like that.. , or does it have separate "time spending" allocations for all of it's bot types. I want to unblock the images folder, for now only the google image bot, but at the same time, I fear that it might drastically hamper indexing of our important pages, as I mentioned before, because of having tons & tons of images, and Google spending enough time already just to crawl that folder.**Any advice? recommendations? suggestions? technical guidance? Plan of action? Pretty sure I answered my own question, but I need a confirmation from an Expert, if I am right, saying that allow only Google image access to my images folder. Sincerely,Shaleen Shah
Intermediate & Advanced SEO | | Modbargains1 -
For URLs that require login, should our redirect be 301 or 302?
We have a login required section of our website that is being crawled and reporting as potential issues in Webmaster Tools. I'm not sure what the best solution to this is - is it to make URLs requiring a login noindex/nocrawl? Right now, we have them 302 redirecting to the login page, since it's a temporary redirect, it seems like it isn't the right solution. Is a 301 better?
Intermediate & Advanced SEO | | alecfwilson0 -
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 -
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 -
PDFs and images in Sub folder or subdomain?
What would you recommend as best practice? Our ecommerce site has a lot of PDFs supporting the product page. Currently they are kept in a sub domain and so are all images. Would it be better to keep them all in a subfolder? I've read about blogs being hosted on a subfolder to be better than subdomain but what about pdfs and images? thoughts?
Intermediate & Advanced SEO | | Bio-RadAbs0