Having a problem at the moment that many of my pages load [using GooglePageSpeed] and seem to load a lot of unused CSS.
If I try and split the CSS - then I get the error that "too many CSS files". I am wondering whether there are any jquery plugins [or other] that are able to RENDER only the CSS for the page that is being loaded and ignore the rest ?
It's sort of like a dynamic CSS interchanger ? Would really help ....
Unless you are sending hundreds of kb of css then it shouldn't really matter.
A dynamic CSS changer would destroy the caching ability of the browser resulting in higher transfers.
I would suggest you to go for Dust-Me Selectors (addon of firefox) to check unused css and delete it for specific pages. Note this is not something allowing you to delete on-the-fly though.
There is a really handy plugin for Grunt called UnCSS. It will automatically remove unused CSS on the fly. Check out this link for more info:
Remove Unused CSS automatically
Seems to me, that it will be bad practice to optimize your css on the fly. Neither on server's side, nor on the client's because it will decrease performance of server/user's browser.
If CSS size is so important for you, it would be a better way to manually create some pre-optimized stylesheets for each global types of pages used in your web application and switch between them.
For this needs, there is one more useful addon for Firefox's Firebug, named CSS Coverage. It allows you to scan multiple pages of your site to see which CSS rules are actually used in your site per each page or per many.
Scaffold might help. It doesn't remove what you don't need, but it does compile it to one small file.
Removing unused CSS would need some JavaScript which would slow down more than the solution above.
Related
I am using google's audit and its tells me to remove unused CSS. I don't know if that css is for just that page or the whole site. The CSS might be there but not needed on that page but another page. Can someone tell me how this works?
It is telling you to remove unneeded CSS for that page.
However you have rightly pointed out the flaw in this suggestion as it only takes into account the current page (in it's initial state, obviously if you have a pop-out menu it won't gather the CSS for that).
Think of it more as a guideline of making sure you don't send the whole of Bootstrap just for the grid and column layouts for example.
Overall this is very difficult to fix, just use the coverage section on the performance tab in Developer tools to make sure you don't have any massively bloated CSS files and you will be fine.
Obviously reduce your unused CSS if it is easy to do so.
The only other thing that this point covers (in it's description, not as part of it's monitoring) is deferring non-essential CSS.
You should defer any Style Sheets that are not required for rendering 'above the fold' content (and inline your 'above the fold' CSS).
This point is also covered in 'Eliminate Render Blocking Resources' so I never quite get why they add the suggestion under this part as well but I have added it for completeness.
I find this rule was good at guiding me when designing a theme from the ground up as it made me seperate global CSS and page CSS more effectively.
Unless your site is scoring 98 / 100 (or you have hundreds of kilobytes of CSS) and you want to squeeze that last little bit of performance out of the site, simply minify and combine your CSS files and ignore this point.
Google's audit tool compares the entire stylesheet against the current URL and then tells you how much of it is actually not used by the browser.
The browser however still needs to download the entire file and then match all CSS selectors that apply to the current URL.
There are many ways to deal with this, but I find it the easiest to use an external API tool like Splitcss that does this for you on URL basis.
If you have only a few URL patterns in your web application, you can use some CLI tools like purgecss or uncss.
I have used lots of code segments for some reasons, like templates, side-bars etc from lots of websites. So that, in my code, i have many not-used css properties. Is there any commands in dreamweaver or any other program to delete not-used css attributes easily?
I am asking this because it will take several hours just to delete them. Image how much it is:)
Thanks
Do you have the site online? If so you can try this site Removed unused CSS.
Also check out the following SO questions they mention the Dust-Me Selector indicated in the comments:
How can I find unused images and CSS styles in a website?
How to identify unused css definitions
Are there any utilities that will crawl a site and determine which css rules are in use and which are not? We have a large site and a huge CSS file (--don't blame me I just got here). And, I think much of it is not being used however I'm afraid to strip stuff out just in case.
The file is confusing and difficult to manage and I think if we can trim it down by getting rid of the unused rules we will have a good starting point to go through and try to make it better.
Try the Dust-Me Selectors Firefox extension by SitePoint. It finds CSS selectors whose rules are never applied to your pages so you can remove them from your stylesheets.
https://addons.mozilla.org/en-US/firefox/addon/10704/?src=collection&collection_id=23d14a2d-b396-c08f-e9ba-b4d34691d5a9
It's an addon in Firebug.
I had the same problem a while ago (5k lines in a CSS) and found this Firefox Plugin which worked very well for me.
The Google Page Speed plugin for Firefox's Firebug addon is also a great tool that will highlight the unused CSS selectors as well as inform you which ones are poor performers.
As always though, you need to be aware that the CSS selector may not be used on "this" page but may very likely be used on another page so be careful when pruning them to ensure they are truly unnecessary.
You can use a service like Unused-CSS
This web app explores the pages of your site and builds clean CSS files
I've been using Google PageSpeed to improve my site's performance. One of its recommendations is eliminating unused CSS in my app. Although a lot of the CSS is unused for a given page, it is used elsehwere in the app.
What's the right approach here? I'm considering creating a base CSS file for common CSS and then separate files for each individual page. Luckily there aren't that many pages. Is this overkill? And is there a better approach?
This is a Rails app, and I'm using asset_packager to minify my CSS and Javascript
Thanks!
Moe
It won't speed up your application because you will be adding new http requests, while if you pack all CSS into one file, that file will stay in the cache and you won't have to have an http-request for it for subsequent pages.
Google PageSpeed simply mean that you shouldn't provide styles you don't use anywhere in your application or only in pages that a user can't visit, for example the admin area.
As people in here mentioned, definitely not. You will just add new http requests. You should really keep in mind that pagespeed will probably always show that you have unused css on a given page, but that's not really a big issue.
Take a look at the other recommandations page speed is showing like enabling compression, optimizing the images (consider using css sprites if you aren't already) and more.
See also yahoo best practices to speed up your site.
That'll depend on the size of the file(s) and the way people use your site. If the file isn't huge to begin with and people will often go to many different pages, having page-specific css files will forfeit the benefit of caching, which is generally going to garner more benefit.
The overhead of an extra HTTP request to download yet another CSS file greatly outweighs the overhead of an extra few KB in the master CSS file.
I think it is best to componentise your stylesheets. For example, you might have a base css that provides the layout for your pages. Then you might have a theme css that provides colours, images, borders - visual elements. Then you might have separate css files for individual UI components, e.g. popup.css, calendar.css etc.
base.css
theme-blue.css
theme-blue-popup.css
theme-blue-calendar.css
This approach makes it easier to manage your styles (and switch them if you need to). More relevant to your question however, is that you now have the ability to specify what stylesheets are needed for each page on your site. Now if the user visits the homepage of your site only, and the homepage has no popups or calendars, then they haven't downloaded the styles for the components they aren't using. As they proceed further into the site, they will get the required stylesheets as and when they need them.
Just wanted to get a few opinions really, I'm trying to increase the loading speed of my site, and one way that Google pagespeed has suggested is to remove the unused CSS from my CSS file for each page.
At the moment I am using one master CSS file for every page on the site.
My question is would having individual CSS files for each page make overall loading times quicker ? I guess the first page would load quicker, but then each page would have a different CSS file which could potentially end up taking longer over a whole site visit ?
Also pagespeed seems to warn against including multiple CSS files so I guess I can't really 'layer' them up...
If the CSS file is cached then including multiple files will not be an advantage.
Note
For performance rules regarding CSS you can
Try minifying your CSS
Optimize CSS Sprites
Avoid Filters
Avoid CSS Expressions
For more detailed reading go through this
Best Practices for Speeding Up Your Web Site
There are two optimisation directives that contradict each other in this case. Of course you should reduce the size of the files if possible, but you should also have as few requests as possible. Using a global style sheet reduces the number of requests, but it means a larger file.
You just have to look into where your needs are. If you need to reduce the initial load time, you should move styles out of the global style sheet. If you need to reduce the number of requests, you should use a global style sheet rather than individual page style sheets.
Download and install YSlow, it will give you an accurate picture of how fast your page is as well as practical steps to improve performance.
I wouldn't worry about it too much. Run your CSS through a filter to strip comments and whitespace, be aware of small shortcuts like padding: 1em 3em .5em 5px etc, make sure the file is being cached properly, and sent from your server with gzipping, and you'll be fine. CSS is usually such a small fraction of the payload, it's not worth losing sleep over.
The only time where I'd split up a CSS file (for delivery to the client) would be if there were large sections of my site which called for unique styles where most people would never venture: eg, an administration section.
Do a little thinking about how the typical user will use your sight. If (like many sites) the average user only views a single page before moving on, then having dedicated CSS files for each page may just be worth it.
However, in the vast majority of cases, a single css file would definitely be the preferred solution
CSS files are cached by browsers anyway, so either you have a single file or many split, it won't matter after all of them got loaded on the first use.
Use just one CSS for all pages. Once your css is cached then there will be no overhead of downloading that css again and again.
Also, ad adam said Minify your css
DustMeSelectors is the extension you need. It will go through all of your site (and providing all of these are inter-linked) will fetch which selectors in your css are not used anywhere.