I have a site whose stylesheets are becoming overwhelming, and a full 50% to 90% or so is not used on certain pages. Rather than have 23 separate blocking CSS sheets, I'd like to find out which are being used on the page I'd like to target, and have those exported into one sheet.
I have seen several questions that recommend "Dust me selectors" or similar add on which will tell what selectors are and are not being used; but that's not what I want. I need to be able to export all used styles from all sheets for that particular page into one new sheet that can be used to replace the 23 others. The solution should be able to support a responsive website (media calls). The website page I'm targeting is: http://tripinary.com.
I've found: https://unused-css.com but this is a paid service and I need free;
The next closest thing I've come across is http://www.csstrashman.com/ but this does not look at stylesheets. In fact, it completely ignores them and ultimately I'm having trouble with the responsiveness of the site. Many times as well, this site just crashes.
I don't mind a programmatic solution if someone has had to do this before and can recommend a direction.
(deleted my comment to RwwL answer to make it a thorough answer)
UnCSS, whether node.js or as a grunt or gulp task, is able to list used CSS rules by an array of pages in an array of Media Queries.
uncss: https://github.com/giakki/uncss
grunt-uncss: https://github.com/addyosmani/grunt-uncss
gulp-uncss: https://github.com/ben-eb/gulp-uncss
Multipage:
You can pass files as an argument to any of the 3 plugins, like:
var files = ['my', 'array', 'of', 'HTML', 'files'],
options = { /* (…) */ };
uncss(files, options, function (error, output) {
console.log(output);
});
Avoid:
urls (Array):
array of URLs to load with Phantom (on top of the files already passed if any).
NOTE: this feature is deprecated, you can pass URLs directly as arguments.
Media Queries and responsive are taken into account:
media (Array):
By default UnCSS processes only stylesheets with media query "all", "screen", and those without one. Specify here which others to include.
You can add stylesheets, ignore some of them, add inline CSS and many other options like htmlroot
Remaining problems:
1/ Conditional classes if you use them for IE9-. They obviously won't be matched in a WebKit PhantomJS environment!
HTML:
<!--[if IE 9]><html class="ie9 lte-ie9" lang="en"><![endif]--> <!-- teh conditional comment/class -->
CSS:
.ie9 .some-class { property: value; ] /* Only matched in IE9, not WebKit PhantomJS */
Should they be added by hand or script to the html element in testing environment? (how it renders is of no importance)
Is there an option in uncss?
As long as you don't style with :not(.ie9) (weird), it should be fine.
EDIT: you can use the ignore option with a pattern to force uncss to "provide a list of selectors that should not be removed by UnCSS". Won't be tested though.
2/ Scripts that will detect resolution (viewport width) and adapt content to it by removing/adding it or adding a class on a container. They will execute in PhantomJS in desktop resolution I guess and thus won't do their job so you'll need to modify calls to PhantomJS or something like that... Or dig into options or GitHub issues of the 3 projects (I didn't)
Other tools I heard of, not tested or barely or couldn't test, no idea about the MQ part:
in grunt-uncss readme, the Coverage part
ucss from Opera (there's already an ansswer here, couldn't make it work)
Helium
CSSESS
mincss
Addy Osmani has countless presentations of 100+ slides presenting awesome tools like this one: https://speakerdeck.com/addyosmani/automating-front-end-workflow (you'll regret even more that days are made only of 24 hours and not 48 err wait 72 ^^)
How about the CSS Usage plugin for Firebug?
Steps:
Visit your page in Firefox
Click "CSS Usage" tab in Firebug
Click the Scan button
Click the bold file name
Save page of CSS selectors to disk
Here are some screen shots and walk through. Not sure about media queries or if it'll work on your site, and it'll probably not keep -webkit etc, but maybe it'll get you part of the way there.
Opera Software released a CSS crawler on Github that claims it can find unused and duplicate selectors. It might do the trick if you're comfortable with a command-line tool. https://github.com/operasoftware/ucss
You Can Check in Google Chrome by doing inspect element (F12) . The unused CSS has Line over the tags.
If you wanted, you could try to build a script that runs on a (non-production) server that goes through every css rule, removes it from the stylesheet, loads the page using something like phantomjs, and checks to see if anything changed from the last time it loaded the page. If so, then put the css rule back, if not, then leave it out and move on to the next rule. It would take a while to run, but it would work. You would also have to setup an instance of your server that does not use caching for it to run on.
Try using this tool,which is just a simple js script
https://github.com/shashwatsahai/CSSExtractor/
This tool helps in getting the CSS from a specific page listing all sources for active styles and save it to a JSON with source as key and rules as value.
It loads all the CSS from the href links and tells all the styles applied from them
You can modify the code to save all css into a .css file. Thereby combining all your css.
Related
I've been using Google PageSpeed insights to try and improve my site's performance, and so far it's proven extremely successful. Things like deferring scripts worked beautifully, since I already had an in-house version of jQuery's .ready() to defer scripts until the page had loaded fully, all I had to do was inline that particular function and move the full scripts to the end of the page. That worked great.
But now I find myself glaring at the one remaining yellow dot on the checklist: "Eliminate render-blocking CSS in above-the-fold content".
The way my CSS is set up is to have one global _.css file containing styles that apply to the page structure in general, or are used in more than one or two places across the site. Most pages then have an associated CSS file (for instance, party.php has party.css) containing styles specific to that particular page. All CSS files are cached indefinitely, as I append /t=FILEMTIME to filenames (and later remove them with .htaccess) in order to guarantee that files are updated when they are changed.
So anyway, Google recommends inlining critical styles needed for above-the-fold content. Trouble is... well, take a look at this screenshot: http://prntscr.com/1qt49e
As you can see... ALL of the content is above-the-fold! People hate scrolling, especially on a game that involves loading many pages. So I designed the site to fit on one screen (assuming a good enough resolution). So that means... ALL of the styles apply to above-the-fold content! So... is there any solution? Or am I stuck with that yellow mark on an otherwise near-perfect score?
A related question has been asked before: What is “above-the-fold content” in Google Pagespeed?
Firstly you have to notice that this is all about 'mobile pages'.
So when I interpreted your question and screenshot correctly, then this is not for your site!
On the contrary - doing some of the things advised by Google in their guidelines will things make worse than better for 'normal' websites.
And not everything that comes from Google is the "holy grail" just because it comes from Google. And they themselves are not a good role model if you have a look at their HTML markup.
The best advice I could give you is:
Set width and height on replaced elements in your CSS, so that the browser can layout the elements and doesn't have to wait for the replaced content!
Additionally why do you use different CSS files, rather than just one?
The additional request is worse than the small amount of data volume. And after the first request the CSS file is cached anyway.
The things one should always take care of are:
reduce the number of requests as much as possible
keep your overall page weight as low as possible
And don't puzzle your brain about how to get 100% of Google's PageSpeed Insights tool ...! ;-)
Addition 1: Here is the page on which Google shows us, what they recommend for Optimize CSS Delivery.
As said before, I don't think that this is neither realistic nor that it makes sense for a "normal" website! Because mainly when you have a responsive web design it is most certain that you use media queries and other layout styles. So if you are not gonna load your CSS first and in a blocking manner you'll get a FOUT (Flash Of Unstyled Text). I really do not believe that this is "better" than at least some more milliseconds to render the page!
Imho Google is starting a new "hype" (when I have a look at all the question about it here on Stackoverflow) ...!
How I got a 99/100 on Google Page Speed (for mobile)
TLDR: Compress and embed your entire css script between your <style></style> tags.
I've been chasing down that elusive 100/100 score for about a week now. Like you, the last remaining item was was eliminating "render-blocking css for above the fold content."
Surely there is an easy solve?? Nope. I tried out Filament group's loadCSS solution. Too much .js for my liking.
What about async attributes for css (like js)? They don't exist.
I was ready to give up. Then it dawned on me. If linking the script was blocking the render, what if I instead embedded my entire css in the head instead. That way there was nothing to block.
It seemed absolutely WRONG to embed 1263 lines of CSS in my style tag. But I gave it a whirl. I compressed it (and prefixed it) first using:
postcss -u autoprefixer --autoprefixer.browsers 'last 2 versions' -u cssnano --cssnano.autoprefixer false *.css -d min/ See the NPM postcss package.
Now it was just one LONG line of space-less css. I plopped the css in <style>your;great-wall-of-china-long;css;here</style> tags on my home page. Then I re-analyzed with page speed insights.
I went from 90/100 to 99/100 on mobile!!!
This goes against everything in me (and probably you). But it SOLVED the problem. I'm just using it on my home page for now and including the compressed css programmatically via a PHP include.
YMMV (your mileage may vary) pending on the length of your css. Google may ding you for too much above the fold content. But don't assume; test!
Notes
I'm only doing this on my home page for now so people get a FAST render on my most important page.
Your css won't get cached. I'm not too worried though. The second they hit another page on my site, the .css will get cached (see Note 1).
Few tips that may help:
I came across this article in CSS optimization yesterday:
CSS profiling for ... optimization
A lot of useful info on CSS and what CSS causes the most performance drains.
I saw the following presentation on jQueryUK on "hidden secrets" in Googe Chrome (Canary) Dev Tools:
DevTools Can do that.
Check out the sections on Time to First Paint, repaints and costly CSS.
Also, if you are using a loader like requireJS you could have a look at one of the CSS loader plugins, called require-CSS, which uses CSSO - a optimzer that also does structural optimization, eg. merging blocks with identical properties. I used it a few times and it can save quite a lot of CSS from case to case.
Off the question:
I second #Enzino in creating a sprite for all the small icons you are loading. The file sizes are so small it does not really warrant a server roundtrip for each icon. Also keep in mind the total number of concurrent http requests are browser can do. So requests for a larger number of small icons are "render-blocking" as well. Although an empty page compare to yours, I like how duckduckgo loads for example.
Please have a look on the following page https://varvy.com/pagespeed/render-blocking-css.html .
This helped me to get rid of "Render Blocking CSS". I used the following code in order to remove "Render Blocking CSS". Now in google page speed insight I am not getting issue related with render blocking css.
<!-- loadCSS -->
<script src="https://cdn.rawgit.com/filamentgroup/loadCSS/6b637fe0/src/cssrelpreload.js"></script>
<script src="https://cdn.rawgit.com/filamentgroup/loadCSS/6b637fe0/src/loadCSS.js"></script>
<script src="https://cdn.rawgit.com/filamentgroup/loadCSS/6b637fe0/src/onloadCSS.js"></script>
<script>
/*!
loadCSS: load a CSS file asynchronously.
*/
function loadCSS(href){
var ss = window.document.createElement('link'),
ref = window.document.getElementsByTagName('head')[0];
ss.rel = 'stylesheet';
ss.href = href;
// temporarily, set media to something non-matching to ensure it'll
// fetch without blocking render
ss.media = 'only x';
ref.parentNode.insertBefore(ss, ref);
setTimeout( function(){
// set media back to `all` so that the stylesheet applies once it loads
ss.media = 'all';
},0);
}
loadCSS('styles.css');
</script>
<noscript>
<!-- Let's not assume anything -->
<link rel="stylesheet" href="styles.css">
</noscript>
I too have struggled with this new pagespeed metric.
Although I have found no practical way to get my score back up to %100 there are a few things I have found helpful.
Combining all css into one file helped a lot. All my sites are back up to %95 - %98.
The only other thing I could think of was to inline all the necessary css (which appears to be most of it - at least for my pages) on the first page to get the sweet high score. Although it may help your speed score this will probably make your page load slower though.
The 2019 optimal solution for this is HTTP/2 Server Push.
You do not need any hacky javascript solutions or inline styles. However, you do need a server that supports HTTP 2.0 (any modern server version will), which itself requires your server to run SSL. However, with Let's Encrypt there's no reason not to be using SSL anyway.
My site https://r.je/ has a 100/100 score for both mobile and desktop.
The reason for these errors is that the browser gets the HTML, then has to wait for the CSS to be downloaded before the page can be rendered. Using HTTP2 you can send both the HTML and the CSS at the same time.
You can use HTTP/2 push by setting the Link header.
Apache example (.htaccess):
Header add Link "</style.css>; as=style; rel=preload, </font.css>; as=style; rel=preload"
For NGINX you can add the header to your location tag in the server configuration:
location = / {
add_header Link "</style.css>; as=style; rel=preload, </font.css>; as=style; rel=preload";
}
With this header set, the browser receives the HTML and CSS at the same time which stops the CSS from blocking rendering.
You will want to tweak it so that the CSS is only sent on the first request, but the Link header is the most complete and least hacky solution to "Eliminate Render Blocking Javascript and CSS"
For a detailed discussion, take a look at my post here: Eliminate Render Blocking CSS using HTTP/2 Push
Consider using a package to automatically generate inline styles from your css files. A good one is Grunt Critical or Critical css for Laravel.
Using developer tools, I can amend a css file for a site I'm currently viewing in a browser.
I want to, effectively, do the same - but instead of amending the css file, loading a local css file, just for that particular domain.
Another way of phrasing it: "When any page of stackoverflow.com is loaded, load C:\test.css to the browser".
Yes, it's possible. Have a look at http://userstyles.org.
Userstyles.org offers CSS files for usage with the extension "Stylish", and Stylish recently announced that they are becoming evil (https://forum.userstyles.org/discussion/comment/109966/#Comment_109966) and can therefore not be used anymore.
One can use the styles with greasemonkey, but then the activation for various websites doesn't work anymore (the CSS is converted into a JS file and the list of sites where it should be applied onto is hardcoded inside an if-statement in that script). I.e. in order to use e.g. "dokuwiki highlight and full width" on a site using dokuwiki but not being http://dokuwiki.org, you have to edit that if-statement and reload.
Is there a way to specify a certain chunk within a custom css stylesheet for a browser to apply to different websites or URLs? For example, Google Chrome's Custom.css or Firefox's userContent.css can be modified to change the appearance of a website, but the changes will apply to every website you visit that share the same tags, id's, classes, etc. Like includes or something?
For Firefox, you can do this using https://developer.mozilla.org/en-US/docs/CSS/#document (needs a -moz prefix at the moment, since it's non-standard).
Chrome and Firefox have defined their own css to be a "default" for rendering certain page elements. This is part of the browser, which is why they can let it be global. You, on the other hand, don't have that privilege.
I have several large CSS files and making a change can sometimes take a few minutes just to find the right selector to change. I would like it if there was a nice ModX editor for CSS, but I haven't been able to find one. I am willing to settle for splitting up my files into parts, as long as my site still renders. Can I do that and how? If there is a nice editor (plugin?) instead, where can I find one?
I guess the real question is what kind of parts are acceptable for you. If you follow this question, you can begin the process of allowing ModX to manage your CSS. Once this happens, your options open considerably. Your CSS editing will then become easier and less time consuming depending on your level of expertise with ModX. This answer will be pretty simple, as it will show simply how to add a given selector as a resource. Other further development can be intuited from here, though.
CSS as a Resource
Once your CSS is being managed as a Resource (which takes about 15 minutes), you may utilize Templates, Template Variables, Chunks, Snippets and Plugins. Thisis actually pretty amazing, but setup can be a bit of a pain. You will basically be investing some time to save a lot of time in the future. The next logical step is split your Selectors accordingly, but you don't want to break what currently works. Having a fluid understanding of the getResources addon will be crucial to further development.
How to do it:
1. Create a new chunk
Click the Elements tab, and click "New Chunk". Name it "css-selector". Set the content to:
[[+pagetitle]] {[[+content]]}
It's as simple as that. Don't forget to click "Save"! This will let you set a Selector as a resource. It will use the title for the selector and content for the rules. You can forget about using those braces any more. Your new chunk will handle those from now on.
2. Adjusting your Template
Now, we just have to convince the template that it nows how to read parts, as well as not forget the whole. Open your CSS Stylesheet template (the one that says [[*content]] for its content). Adjust the code so that it has the following:
[[!getResources?
&parent=`[[*id]]`
&depth=`1`
&tpl=`css-selector`
&includeContent=`1`
&sortby=`menuindex`
&sortdir=`ASC`
&limit=`99`
]]
[[*content]]
Again, click "Save". Let me explain the Template real quick. If you have child, they'll get rendered first depending on their menu index. Further, it will render the contents of the document that are not children afterward. This will allow you to only make new resources for your most important selectors, while keeping the stuff that will never change in the main resource.
3. Create a new Template
This is so that your selectors don't do anything funny and just render the content. Create a new Template named "CSS Selector". Set its content to:
[[*content]]
4. Create a new Resource
Create a new Resource. Set the title to the selector for the css statement you want to manage. Then set the content to the rules without the braces. For instance, if your css statement is: div#header .logo {border:0;}, you'll set the title to div#header .logo and the content to border:0;. Set the resource alias to whatever you want. I use numbers for each one. Set the template to your new "CSS Selector". Important Now, set the Parent Document to your Stylesheet. Click Save.
5. Testing the Stylesheet
First, Right-click your new resource and choose "View Resource". This will just make sure that the statement was rendered correctly. It should simply say your rule in CSS format.
Next, Right-Click the Stylesheet resource and choose "View Resource". You should see the Selector at the top and all of the other rules below it.
Final Considerations
Observations
You'll notice that your child resources do not have to be changed to "CSS" for Document Type. Only the parent stylesheet has to be. This allows for some neat stuff as your expertise with ModX grows.
You can change the order of rules by simply changing the menu index of them.
The number of rules that can be done this way is based on the &limit variable in the getResources statement in your template. &limit applies to each stylesheet, so in this example you have 99 statements per stylesheet that may be separate resources.
A Note on Server Load
This will place load on the server as the number of resources goes up. For development, keep the "do not cache flag" (!) on your getResources statement. Once you are done, remove the exclamation mark and let it all be cached. This will save a ton of load.
Further Development
I added an isEnabled template variable to mine so I can turn on and off each rule as I pleased.
You may possibly begin to manage your CSS on the front-end utilizing FormIt.
Custom Manager Pages may even be a better option for you.
Further abstraction might allow you to create Groupings of statements for even further organization.
We've reached the end of our tether here trying to overcome a nasty and intermittent FOUC in Firefox 3.5.x+ for a new release we're working on.
We've tried:
Disabling Javascript in FF
Using Quirks mode rendering by removing the DOCTYPE
Moving from #import for additional CSS to <link>
Switching concatenation on and off
Removing CSS files from the concat, one at a time
Switching the local cache off in Firefox
etc
Our previous release never exhibited any FOUC issues, so it's something we've done to this release. Changes we've made so far include:
Using Base64 encoded images over Data URIs for all decorative imagery, served via CSS.
Separating 'framework'-related CSS files from page-specific CSS and bundling them as two separate CSS files
To recreate the problem... use Firefox 3.5.x or 3.6.x, then:
Head on over to: http://my.publisher-subdomain.env.yola.net/
Login with username: 'stack#yola.com' and password: 'stackoverflow'
Once logged-in, you should be at http://my.publisher-subdomain.env.yola.net/sites/
Click the Account link in the main nav.
The Account page should load, and you should see a FOUC. If the FOUC does not occur, clear your cache and reload the page.
Your help would be greatly appreciated! :)
UPDATE:
The dev environment is still exhibiting the FOUC, but only if FireFox is running low on memory or has a lot of extensions installed. Latency and rendering speed definitely affect the visibility of this FOUC.
Although this is a very old question, I found it when I was searching for a solution to the same problem. So, I wanted to post the solution for future reference. I just needed to move the reference to my CSS files above the references to external Javascript that needed to be in my header.
I can be wrong, but this could be a concurrent connections issue. According to my Firebug's "Net" tab
the HTML page simply takes a lot of time to load - maybe also because it is on a development server? - and the style sheet gets loaded after the HTML page.
I can't claim to entirely understand what's happening here, but I would try putting the style sheet onto a different domain as a first measure. That should make Firefox establish a connection straight away.
It would probably also be a good idea to go back to normal images instead of data: URIs - that would reduce the size of the style sheet, and data: URIs won't work at all in IE < 8.