srcset and sizes attributes - [ images on the web | part one ]

[@RachnaChavan-n7w]

What an explanatory video, loved the math formula tip you showed based on device widths. Thanks a lot for this amazing takeaway about srcset

[@RussDnB]

Every time I think I've learned what I need to know, I find something new, lol Been working on a site for just over a month now, and stumbled across this today. Thanks for this video Kevin!

[@krtecek-who-tries]

Thank you! I was struggling to understand why one and the same image is loaded no matter which screen size I set in Chrome Dev Tools responsive emulator, and your video was really helpful :)

[@jamesauble8091]

At 9:56 you suggest to use the lowest quality image, but devs may bear in mind that this isn't always the best option. In many situations you might actually want to provide the best quality image at the sacrifice of bandwidth to the end user. The reason for this would be that just because the end-user is using an old browser, this doesn't necessarily mean they're on a poor connection. Granted, there may be a correlation, but this should be taken case-by-case.

[@denisdeleon2271]

Thank you. Good explanation of srcset and what the browser is doing.

[@hiwayshoes]

Thank you so much for your help with images, Kevin! Your tutorials are always the best!

[@rafa6536]

Maybe it is a great solution. I didn't know about it. I am learning and on my blog, which I am making to learn while doing it, I have sometimes a post with a lot of pictures. Load time was crazy slow, but the column is not wide, so I wrote myself JavaScript code and server side code which is returning to the user the smallest possible picture depending on column width. Now I think I have to rewrite it using srcset + sizes :) Thanks!

[@jibkas]

There should be another option in polls " Doesn't matter". Because for me it doesn't matter Code pen or VS Code. I'm more interested in topic. Great tutorial BTW.

[@KevinPowell]

I thought about it, but I figured I'd force people to make a decision :P - Glad you enjoyed the video!

[@magoxxii]

Great video! i loved the use of cats. not anymore in new videos =P thanks as always kevin! you make it so clear, today i saw 4 more videos about it, all of them bring some to the table but yours always is the most educative and descriptive. thanks again from 2024!

[@KyleMerl]

wow... This is the video that I didn't know I needed. I used media queries and, if I remember correctly, the visibility property to achieve that same effect. using srcset seems so much easier!

[@JBuchmann]

I think doing it with media queries and css visibility isn't really helping with lowering bandwith. You're still downloading all the image versions. With srcset you literally are downloading only the single best sized image depending on the browser width, resolution, etc.

[@KyleMerl]

I agree. I'm going to have to use this going forward.

[@KevinPowell]

Yup, as John mentioned, this will load in all the images. You'd be better off just loading in one big image in that case I believe. You'll probably really like the picture element once I get there next week :)

[@andrejmarffy3368]

Thanks Kevin! Very well explained. Great help for me.

[@YvonneVibe]

so enjoyable when watching your every video! thoughtful and clear

[@stephenbrown1567]

Thank you, I have read loads of tutorials and they dont explain it as clearly as this. Just one question how do you do the same for background images?

[@danaifessahaie203]

Great video, thank you for the info! I have one question regarding 2x-3x retina screens. If a mobile device has a 3x screen should it download the highest quality image? Aren't mobile devices the ones with the most questional connections and where you want to your website to run the smoothest? If a mobile device downloads all the highresolution images and slows the website down then whats the point? Fundamentally I guess my question is should you strictly adhear to the screens pixeldensity or is it acceptable to stray away from it and follow your own preference if you feel thats best? What is best practice here? (new to this :D )

[@ahsanhabibasha6906]

It was really helpful to me and thanks a lot for this.

[@briangibson3803]

Pole?.. IDE/Text Editor over Code Pen any day... as a newbie just nice to see all the code, not just the CodePen content code (it that made sense?).. and then write it myself in the same editor as VSC and Atom seem to be everyone's flavour at the mo.. Just a lot easier for a newbie to feel out and understand.. Keep up the awesome work dude! : )

[@KevinPowell]

Thanks for the feedback!

[@The1stKing]

Oh man, i loved the video! Thank you so much for making it. God bless you sir.

[@1337ghomri]

Nice video! Finally understand it

[@gaziev__9797]

I love you! In the ru community, little is said about it

[@eip408]

Awesome, I believe that this are indeed needed. Thanks🙌🏼

[@erock3737]

Great video - thank you.

[@RichardShire]

Great video Kevin, really helpful info, thank you!

[@PerfectSwingDance]

Any good ways to automate such process today?

[@esraaabdelaziz485]

thank you so much for that video this really made it easy for me to use srcset attribute and understand it very well

[@DamianDemasi]

Thank you! I finally understood this!

[@Faruk-zt5iw]

Thanks, I feel like I'm ready to implement this on the real project :)

[@hashaama]

your every video is amazing keep it coming sir!!

[@KevinPowell]

Thanks Hashaam!

[@DrNio-sh5mx]

Great work

[@CarlitoProductions]

this explains well what i had trouble with. thank! question though: for the media queries for the size property, can we somehow access srcset inside of css and implement the properties there? Or something similar?

[@Natalie-gw8jt]

Great video!! Quick question, how do you get different sizes of the same image?

[@PotatoLeagueStudios]

Kevin, you are awesome! I love your videos!

[@KevinPowell]

Thanks Ethan :)

[@developerfriendly]

güzel anlatmışsın, tebrik ederim

[@rmnkot]

Any topic that touches accessibility, performance and it optimisation is very useful nowadays

[@KevinPowell]

I'll have some accessibility videos coming early in the new year 👍

[@rmnkot]

@@KevinPowell I'll be waiting!

[@mattcunningham2597]

The image width (500w) doesn't have to match your images actual width. you could just put your viewport target in there.

[@kyleklaiber2225]

@kevin powell thanks for this! Did you ever do a part 2 for this? 28:00 I am looking to include something like this in the theme I'm building and not finding any solutions that I like so far!

[@abhijitbarman4401]

very informative video🧡🧡

[@alenamekhnina-marcalle5234]

Thank you so much for this video! Helped me a lot!

[@lakeacres9750]

Very well explained! Thanks!

[@muralikrishnam5624]

what is 500w 1000w 1500w? Is it work responsive when i resize browser.

[@stephenaitken1560]

What an excellent tutorial.

[@nimbostratue]

In chrome it does not eve work when I disable the cache and refresh. If you start with the browser window size small it will choose the smallest image and then scale up to the larger images as you increase the size of the browser. If you shrink the browser, the largest image will remain selected. It works fine on firefox though! It only works on chrome if I refresh the page, but I need it to work when I resize the page as well. Is it possible?

[@KevinPowell]

Once it's loaded in the bigger version, it has no reason to drop to smaller ones. I think you might be after using the picture element, which lets you bring in different images based on screen size. I cover that later in this series 👍

[@TheTallMan67]

so good. Thank you!

[@michalroesler]

I would prefer you write code in VS Code, because this is my text editor of choice. And many other people use it as well. And it's open source.

[@shaunpalmer9558]

I'm currently developing a new theme for my WordPress site only to come off Cross a background image that I need to swap out for the large one to the smaller one and setting the small one is default I think this might be easy until you try to do it on top of that I chose to use Bootstrap for main CSS framework I didn't find it natural way of doing this until I come across the research that I did for this little section background image swap it out for a small one I should use webP Have you got any videos where you dig into the sort of thing and swapping out images for a smaller one it seems so straight for a concept until you're trying to dig into it dug around to see if you had any videos about it but this is the only what I seem to have come across any chance you doing something about this in the future Sorry about my poor English I got dyslexia

[@KevinPowell]

background images are harder to deal with, sadly. You could use some JS for it if you really need to, and it could be something that I look into in the future :)

[@onnot701]

@Kevin, you started with saying that its important for loading speeds ex. data on mobile phone. Yet you ended up with loading 2x or 3x on mobile due screen quality of the mobile phone. Can you elaborate on this? btw: big thxs for the channel!!

[@KevinPowell]

The spec does allow the browser to use a lower quality image if it has reason to (slow connection speed, data saver, etc). Now, that is up to the browser to actually do that, and in all my reading, I can't say if they do or don't consistently (which is why I didn't really talk about it). Still, getting a 2x image that's scaled properly can be a much smaller file than a giant jpg that people might use to 'cover all the bases'. And by people, I mean myself, quite often, lol. The difference in the 2x and 3x can be double the file size. It's why I like the 'width' solution better than the device pixel density solution. The browser will simply pick the image that works best in that specific situation.

[@SimonTheFlash]

at 19:37 why does he do the math 500 / 360? where does that formula come from?

[@daveskye]

Good Video. What can we do for users with 3x screen but a slow internet connection?

[@KevinPowell]

The spec does give the browser the authority to download what it thinks is best, so if there is a slow connection (or data saver is enabled) the browser could choose a different version. I didn't talk about it in the video because i couldn't find any info on which bowsers, if any, actual implement those choices or not.

[@chuckcoughlin3112]

No poll pop up, but I prefer VS code.

[@CreativeJE]

you should be using chrome for all of your videos cause most people use it and it will be easy for us to learn

[@KevinPowell]

I use Chrome day to day, but it's my development browser, and I'd champion everyone switching to it, even if it's just to use as a development tool. It's dev tools are way ahead of Chrome, specially in relation to Grid. And for the most part, the layout is almost the same, so I don't think it should cause much confusion.

[@hyfytale9577]

I was having a hard time testing this. My firefox developer tool -> Network panel won't show up what is being loaded. :( Does anyone know how to show what image has been downloaded in the Firefox developer tool -> Network?

[@cerealrakist7360]

Are you trying this by using the code he provided and are wanting to see that same cat, or are you using a different image, that you have?

[@popukuttansvlog1106]

♥️

[@mohdeshtiwi629]

This is hard :o

[@kite4792]

🙏 thanks

[@shaunpalmer9558]

A Prefer your text editor, post it, Code somewhere like On your blog

[@klartext1451]

Boom

[@cowboyfrankspersonalvideos8869]

This shows that you CAN teach an old dog new tricks. You say that WordPress defaults to srcset. I don't use WordPress so am not familiar with its internals. I'm constantly seeing WordPress sites with 2 to 5 meg thumbnails. Does the creator have to upload the 3 different images sizes to make this work. or is a properly configured WordPress site supposed to create the 3 images itself? Personal opinion: I don't think most sites that are using WordPress (or Joomla etc) should be. Amateur webmasters are using these things without understanding the tremendous load they are putting on shared servers. I can almost always tell when I am opening a WordPress site because they are slower to open. If you're building a dynamic site, sure, use WordPress, but if you're building a static site, spend a bit of time and learn how to use a publishing tool rather than a content management tool.

[@KevinPowell]

WordPress should be doing all the work for this behind the scenes. If you upload a large image, it'll make several versions of it right away. If a thumbnail is several MB in size, it's an issue with the theme. This has been built into the core of WP since 2015. I agree that WP is overkill a lot of the time, and it's a shame there are so many bloated and bad themes out there for it, because it's not a bad platform.

[@kevinwaelkens1195]

Hey Kevin. Thanks for taking the time to create and upload this, it's pretty tricky to wrap your head around srcset's behaviour sometimes. I still can't figure out though why I'm having this problem though: bit.ly/2MLAixa - I thought the calculations you talked about getting over your DPR would give me the aha-moment, but the math doesn't work out in my example I'm afraid. Any chance you could help me see through this issue? Thanks 🙏

[@KevinPowell]

I read your post asking it, and tried out the pen... but for me, it changes exactly when you'd expect it to.... so I'm not sure what might be happening, unless your device resolution is higher than 1x?

[@kevinwaelkens1195]

@@KevinPowell cheers for your answer, I am indeed on a retina mbp. However, that DPR is 2, so shouldn't it jump at your values times two then? It jumps to another image at a really random value I find...

[@MrPDTaylor]

Second :(

[@sciencehub5197]

You're amazing. I just finished my website project last week by following your advice. I wish this video was out two weeks ago haha

[@williamzhou3438]

Thank you. I was reading and practicing about this topic but still not understanding it clearly until I watched your video. Now I'm confident enough to apply it on my own project. I really appreciate your explanation, and look forward to seeing more of your videos.

[@cchana]

The video on srcset I wish I watched at least 2 years ago! As ever, really well explained and great demo. In some sense, I feel like the solution is over complicated at the CSS level but this was more than enough to help get my head around it. Thanks, Kevin!

[@taospencer1403]

Trying to get these images to be responsive here: @: www.elysiumfields.net been playing around with vmin & vmax for the container divs and using overflow:hidden to crop. Still can't get them to be fully responsive but never heard of these (srcset & picture) two before.. i've been using just regular img tags. Thanks for the tutorial. Subscribed

[@Lilliebeth001]

Hi Kevin, thank you. This is really interesting, as always. How would i apply this when I am using an img as a background in css though?

[@juliocodes]

Great job as usual, Kevin. The way you explain things is very clear which makes it easier to understand!

[@GoogleUser-es9vs]

Thank you so much!!!

[@salhakim2322]

Great video, I’m wondering what people’s thoughts are on automating sizing picture sizes? Ideally, I’d like to output sizes in webp for most viewports and jpegs for mobile since support still isn’t there.

[@scottonanski4173]

Dang, Kevin. I have to say that whenever I'm struggling to understand a layout concept, you're videos are always so refreshing. You're a gifted teacher. Simple, to the point, and practical.

[@a4yster]

I believe if you install IE you should be able to claim Social Security at any age.

[@Yetipfote]

I think if you install IE it should come with a gun with a single bullet in it.

[@Yetipfote]

Thanks god no Okulele background music.

[@cerealrakist7360]

You’re my new best friend. I like that statement and second that! 🙌🏻✌🏻

[@ArneM7]

At 16:35, you say something like "as my window size is bigger as this (pointing at 1500), it will use this image (pointing at img/cat-1500.jpg). This is incorrect, it will start using img/cat-1500.jpg when the window size is bigger as 1000px.

[@mazeetech]

How can i like this video multiple times ?

[@ntantar]

Javascript...

[@yuliethemstedt8619]

Hey Kevin, this was sooooo helpful. I'm currently building an image-heavy website ... and I never fully took the time to understand all the parameters available in srcset ... this was an excellent workshop and just took half an hour. Thank you so much!

[@leonardmbibi8013]

First,Thanks for the video. Secondly, I did not get good results: without the media query, my browser never changed img as I resized. Thirdly, with the media query in place, transitions occurred way earlier than expected. Finally, I ended up using the element for my project.

[@abraund]

Well instinctively it feels anti-semantic, the sizes property especially. Html is for document classification, css is for presentation. Still I'm just a backend dev learning really, so pinch of salt on these early thoughts, but I would try not to use this. If I perf tested page load, and it exceeded some arbitrary limit, and then on investigation noted it was slow due to image loads then perhaps I would consider this at that point. Even there I'd be more inclined to throw extra hardware, or a CDN, at the problem, long before getting this finicky.

[@TokyoNerd]

Another very helpful video. These videos always help me to learn a new way to improve my website!

[@Alessandro__]

Just a question. If in src you specificy the 500px, but than the browser understand that it's better the 1000px, how the loading process works? Is it first loaded the 500px and than substituted with the 1000px or it is directly loaded the 1000px?

[@etiena]

I do not know if it is possible but it would good to set srcset to none as replacement of display:none whenever you do not want to show an image under a certain width. For example on mobile devices I tend to hide some images, but with display:none the image will be loaded anyway.. Do you have any suggestion? Thanks in advance and thanks for sharing all your knowledge to us

[@CodingBandit]

where do you get pictures with different widths

[@kostiantynkarzhanov9216]

Awesome and very well explained tutorial! Kevin, thank you so much! 💛

[@TheDexter89]

I see this source set in wordpress but I don't know the concept behind it. Today I understand it and use it for my HTML website Thanx Kevin

[@greenworld7085]

I was stuck for hours to figure out "clearing the cache " before I came 2 this video. But I found it in your video. U saved the day. thanks a lot...

[@PaulMcCannWebBuilder]

Also, when dev tools are open in Chrome, you can long click (click and hold) on the reload icon in the browser's toolbar and you get the option to 'empty cache and hard reload'.

[@AlessandroManente]

thanks a lot for the channel, awesome video, and i'm definitely going to use srcset for my personal page!

[@OctavianContis]

Nice but how to make this work with "width" and "height" img attrigutes while also not triggering errors in Lighthouse reports?

[@aram5642]

What a fantastic tutorial! Like a missing manual!

[@Alessandro__]

Does the algorithm also evaluate the network speed? So based on this it can choose if load an low quality image as compromise

[@slammerton]

Awsome vide! How would i apply this when I am using an img as a background in css though?

[@gaborszekely8387]

YES!!! You came through on kitten, as promised. I now have no choice but to Patreon this channel.

[@KevinPowell]

Haha, I'll make sure to keep them up :)

[@sakarsr]

Nice to know about (scrset). VSCode explanation is good. Use VSCode in all your code examples. Good health.

[@level9teamplayer]

Ty. This was confusing at first buy you made it pretty simple and easier to understand.

[@Human_Evolution-]

Cool hair style... Need to add some CSS to that lol

[@aminbeee]

If I could put more likes on this video, I would do it! many thanks :)

[@yabuking84]

Im still confused. How was sizes attribute able to select which image to use in srcset?

[@Marceloamado1998]

Very clear explanation. Thank you man

[@jimdart8219]

Awesome. You have no idea how badly I need this on a project right now. Thanks a million Kevin.

[@jivanmainali1742]

But how do you put those width into img srcset when imgae is being loaded from backend

[@gmoneybags01]

Hey Kevin, do you have any videos on how to use grunt to make images responsive?

[@johnKeysCloudSonics]

I plan on using this for product item photos on e-commerce sites.

[@ViktoriaLukyanchuk]

I finally understood this concept of size!

[@threeone6012]

Kevin lost weight since this. Good job!

[@onur-9158]

I'm a beginner. How can I rotate img when I extend the page size ?

[@SiddharthSharma15]

Thank you so much, extremely clear.