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.
- topic:timeago_earlier,17 days
-
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
-
Images on their own page?
Hi Mozers, We have images on their own separate pages that are then pulled onto content pages. Should the standalone pages be indexable? On the one hand, it seems good to have an image on it's own page, with it's own title. On the other hand, it may be better SEO for crawler to find the image on a content page dedicated to that topic. Unsure. Would appreciate any guidance! Yael
Intermediate & Advanced SEO | Oct 8, 2019, 10:39 AM | yaelslater1 -
Text over image
Hello, I am creating an overlay on a image. Is it ok to write on this overlay in html or it is better to have the text not on a image for google and other search engines ? Thank you,
Intermediate & Advanced SEO | Sep 1, 2023, 9:13 AM | seoanalytics0 -
Switching from Http to Https, but what about images and image link juice?
Hi Ya'll. I'm transitioning our http version website to https. Important question: Do images have to have 301 redirects? If so, how and where? Please send me a link or explain best practices. Best, Shawn
Intermediate & Advanced SEO | Sep 9, 2016, 2:57 PM | Shawn1241 -
Heading Tags (Specifically H2) being used within images
Hello, Mozzers I have a question regarding placement of heading tags. I have seen this asked a few times on the forum but some are from a couple years ago so wanted to get a more up to date answer regarding this. We want to add H2 tags across our site but our two options are to wrap images we are using as navigation on the top of the page, these are directly below our pages H1 tag and actually make sense. Example H1 title: Vehicles Images are specific brand logo with H2 being wrapped to pull the img alt: "Ford Vehicles" "Checvy vehicles" etc. The wrap would look something like this: I appreciate your time, Chris
Intermediate & Advanced SEO | Jun 16, 2016, 11:41 AM | kirin443550 -
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 | Aug 10, 2015, 4:35 PM | 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 | Jan 21, 2015, 6:34 AM | Modbargains1 -
Should I redirect images when I migrate my site
We are about to migrate a large website with a fair few images (20,000). At the moment we include images in the sitemap.xml so they are indexed by Google and drive traffic (not sure how I can find out how much though). Current image slugs are like:
Intermediate & Advanced SEO | Jul 7, 2014, 10:49 AM | ArchMedia
http://website.com/assets/images/a2/65680/thumbnails/638x425-crop.jpg?1402460458 Like on the old site, images on the new website will also have unreadable cache slugs, like:
http://website.com/site_media/media/cache/ce/7a/ce7aeffb1e5bdfc8d4288885c52de8e3.jpg All content pages on the new site will have the same slugs as on the old site. Should I go through the trouble of redirecting all these images?0 -
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 | Feb 3, 2014, 4:15 PM | WhiteboardCreations0