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]
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
-
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 -
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 | | Shawn1241 -
Priority Attribute in XML Sitemaps - Still Valid?
Is the priority value (scale of 0-1) used for each URL in an XML sitemap still a valid way of communicating to search engines which content you (the webmaster) believe is more important relative to other content on your site? I recall hearing that this was no longer used, but can't find a source. If it is no longer used, what are the easiest ways to communicate our preferences to search engines? Specifically, I'm looking to preference the most version version of a product's documentation (version 9) over the previous version (version 8). Thanks!
Intermediate & Advanced SEO | | Allie_Williams0 -
Is it worth creating an Image Sitemap?
We've just installed the server side script 'XML Sitemaps' on our eCommerce site. The script gives us the option of (easily) creating an image sitemap but I'm debating whether there is any reason for us to do so. We sell printer cartridges and so all the images will be pretty dry (brand name printer cartridge in front of a box being a favourite). I can't see any potential customers to search for an image as a route in to the site and Google appears to be picking up our images on it's own accord so wonder if we'll just be crawling the site and submitting this information for no real reason. From a quality perspective would Google give us any kind of kudos for providing an Image Sitemap? Would it potentially increase their crawl frequency or, indeed, reduce the load on our servers as they wouldn't have to crawl for all the images themselves?
Intermediate & Advanced SEO | | ChrisHolgate
I can't stress how little of a hardship it will be to create one of these automatically daily but am wondering if, like Meta Keywords, there is any benefit to doing so?1 -
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 -
Alt tag for src='blank.gif' on lazy load images
I didn't find an answer on a search on this, so maybe someone here has faced this before. I am loading 20 images that are in the viewport and a bit below. The next 80 images I want to 'lazy-load'. They therefore are seen by the bot as a blank.gif file. However, I would like to get some credit for them by giving a description in the alt tag. Is that a no-no? If not, do they all have to be the same alt description since the src name is the same? I don't want to mess things up with Google by being too aggressive, but at the same time those are valid images once they are lazy loaded, so would like to get some credit for them. Thanks! Ted
Intermediate & Advanced SEO | | friendoffood0 -
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