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
-
Google Image Search - Is there a way to influence the related icons at the top of the image search results?
Google recently added related icons at the top of the image search results page. Some of the icons may be unrelated to the search. Are there any best practices to influence what is positioned in the related image icons section? Thank you.
Intermediate & Advanced SEO | | JaredBroussard1 -
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 -
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 -
High resolution (retina) images vs load time
I have an ecommerce website and have a product slider with 3 images. Currently, I serve them at the native size when viewed on a desktop browser (374x374). I would like to serve them using retina image quality (748px). However how will this affect my ranking due to load time? Does Google take into account image load times even though these are done asynchronously? Also as its a slider, its only the first image which needs to load. Do the other images contribute at all to the page load time?
Intermediate & Advanced SEO | | deelo5551 -
Google Not Indexing XML Sitemap Images
Hi Mozzers, We are having an issue with our XML sitemap images not being indexed. The site has over 39,000 pages and 17,500 images submitted in GWT. If you take a look at the attached screenshot, 'GWT Images - Not Indexed', you can see that the majority of the pages are being indexed - but none of the images are. The first thing you should know about the images is that they are hosted on a content delivery network (CDN), rather than on the site itself. However, Google advice suggests hosting on a CDN is fine - see second screenshot, 'Google CDN Advice'. That advice says to either (i) ensure the hosting site is verified in GWT or (ii) submit in robots.txt. As we can't verify the hosting site in GWT, we had opted to submit via robots.txt. There are 3 sitemap indexes: 1) http://www.greenplantswap.co.uk/sitemap_index.xml, 2) http://www.greenplantswap.co.uk/sitemap/plant_genera/listings.xml and 3) http://www.greenplantswap.co.uk/sitemap/plant_genera/plants.xml. Each sitemap index is split up into often hundreds or thousands of smaller XML sitemaps. This is necessary due to the size of the site and how we have decided to pull URLs in. Essentially, if we did it another way, it may have involved some of the sitemaps being massive and thus taking upwards of a minute to load. To give you an idea of what is being submitted to Google in one of the sitemaps, please see view-source:http://www.greenplantswap.co.uk/sitemap/plant_genera/4/listings.xml?page=1. Originally, the images were SSL, so we decided to reverted to non-SSL URLs as that was an easy change. But over a week later, that seems to have had no impact. The image URLs are ugly... but should this prevent them from being indexed? The strange thing is that a very small number of images have been indexed - see http://goo.gl/P8GMn. I don't know if this is an anomaly or whether it suggests no issue with how the images have been set up - thus, there may be another issue. Sorry for the long message but I would be extremely grateful for any insight into this. I have tried to offer as much information as I can, however please do let me know if this is not enough. Thank you for taking the time to read and help. Regards, Mark Oz6HzKO rYD3ICZ
Intermediate & Advanced SEO | | edlondon0 -
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 -
Hosting images on multiple domains
I'm taking the following from http://developer.yahoo.com/performance/rules.html "Splitting components allows you to maximize parallel downloads. Make sure you're using not more than 2-4 domains because of the DNS lookup penalty. For example, you can host your HTML and dynamic content on www.example.org and split static components between static1.example.org and static2.example.org" What I want to do is load page images (it's an eCommerce site) from multiple sub domains to reduce load times. I'm assuming that this is perfectly OK to do - I cannot think of any reason that this wouldn't be a good tactic to go with. Does anyone know of (or can think of) a reason why taking this approach could be in any way detrimental. Cheers mozzers.
Intermediate & Advanced SEO | | eventurerob0 -
Blocking Pages Via Robots, Can Images On Those Pages Be Included In Image Search
Hi! I have pages within my forum where visitors can upload photos. When they upload photos they provide a simple statement about the photo but no real information about the image,definitely not enough for the page to be deemed worthy of being indexed. The industry however is one that really leans on images and having the images in Google Image search is important to us. The url structure is like such: domain.com/community/photos/~username~/picture111111.aspx I wish to block the whole folder from Googlebot to prevent these low quality pages from being added to Google's main SERP results. This would be something like this: User-agent: googlebot Disallow: /community/photos/ Can I disallow Googlebot specifically rather than just using User-agent: * which would then allow googlebot-image to pick up the photos? I plan on configuring a way to add meaningful alt attributes and image names to assist in visibility, but the actual act of blocking the pages and getting the images picked up... Is this possible? Thanks! Leona
Intermediate & Advanced SEO | | HD_Leona0