I'm having a problem with a site that I just made live - I had to correct some CSS issues related to the background and some image placements. Everything of course looks great in VS Code. I open it in Chrome and Firefox and they look completely different - and wrong. Developer tools showed they were using the old CSS stylesheet (which was originally loaded, then replaced). If I open an incognito window, all is perfect. Any reason this would be? I'm new to this (changing careers) so I appreciate your insight!
This is most probably because the css file is cached in your browser. To fix this problem, you can use cache buster in the URL. For ex, your CSS URL is
https://www.abc.xyz/static/css/core.css
So, whenever you make changes in the CSS file, change the URL to this
https://www.abc.xyz/static/css/core.css?version=1.0.1
?version=1.0.1 changes the file URL and hence it is not loaded from cache. Just change the version number when you make the changes to the file so the URL is new again
When I update a js file in my asp.net project, I refresh the browser and the change shows up as expected. If I change a css file or an .aspx file, the change does not show in the browser. Not when I clear the browser's cache, not when I restart IIS (iisrestart). What could this possibly be?
PS. I have tried chrome and firefox
Your browser loves to cache files such as CSS, JS and XML docments.
Do a "hard refresh" to tell your browser to download everything again.
Typically, it's CTRL-F5
You can also append a random number to the end of the file name so that it's never the same and the browser will snatch it up each time.
I have observed weirdness like this in chrome, but not firefox.
When you open it in firefox with firebug, are you seeing a 304 code? That might help separate server side issues from client issues.
I've had this problem a couple of times. Adding a random querystring value on the end of the URL for CSS seemed to fix things. So if your URL was /css/styles.css, just put in some code to add a random number on the end so the URL looks like /css/styles.css?random=2345.
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.
When I make any changes to my CSS file, the changes are not reflected in the browser. How can I fix this?
The fix is called "hard refresh"
http://en.wikipedia.org/wiki/Wikipedia:Bypass_your_cache
In most Windows and Linux browsers: Hold down Ctrl and press F5.
In Apple Safari:
Hold down ⇧ Shift and click the Reload toolbar button.
In Chrome and Firefox for Mac:
Hold down both ⌘ Cmd+⇧ Shift and press R.
Try opening the style sheet itself (by entering its address into the browser's address bar) and pressing F5. If it still doesn't refresh, your problem lies elsewhere.
If you update a style sheet and want to make sure it gets refreshed in every visitor's cache, a very popular method to do that is to add a version number as a GET parameter. That way, the style sheet gets refreshed when necessary, but not more often than that.
<link rel="stylesheet" type="text/css" href="styles.css?version=51">
A good way to force your CSS to reload is to:
<link href='styles.css?version=1' rel='stylesheet'></link>
And then just increment the version number as you change your CSS. The browser will then obey. I believe Stack Overflow uses this technique.
I always use Ctrl+Shift+F5 out of habit, it should force a full-refresh including by-passing any http proxies you may be going through.
I had this issue. Turns out I completely forgot I had CloudFlare setup on the domain I was live testing on.
CloudFlare caches your JavaScript and CSS. Turned on development mode and BAM!
Do Shift+F5 in Windows. The cache really frustrates in this kind of stuff
This sounds like your browser is caching your css. If you are using Firefox, try loading your page using Shift-Reload.
Having this problem before I found out my own lazy solution (based on other people suggestions). It should be helpful if your <head> contents go through php interpreter.
To force downloading file every time you make changes to it, you could add file byte size of this file after question mark sign at the end.
<link rel="stylesheet" type="text/css" href="styles.css?<?=filesize('styles.css');?>">
EDIT: As suggested in comments, filemtime() is actually a better solution as long as your files have properly updated modify time (I, myself, have experienced such issues in the past, while working with remote files):
<link rel="stylesheet" type="text/css" href="styles.css?<?=filemtime('styles.css');?>">
The Ctrl + F5 solusion didn't work for me in Chrome.
But I found How to Clear Chrome Cache for Specific Website Only (3 Steps):
As the page is loaded, open Chrome Developer Tools (Right-Click > Inspect) or (Menu > More Tools > Developer Tools)
Next, go to the Refresh button in Chrome browser, and Right-Click the Refresh button.
Select "Empty Cache and Hard Refresh".
Since I found this thread having the same problem, 10 YEARS later, I'll add my own solution too. I use PHP most of the time, and rather than requiring the user to press unusual buttons to refresh the page, or myself to remember to bump a version number embedded in a link, I used the filemtime() function to get the modification time of the css file (as a unix timestamp), and then use THAT number as the parameter.
$FILE_TIME = filemtime("main.css");
$CSS_LINK = "main.css?version=$FILE_TIME";
While results in a URL like:
http://example.com/blah/main.css?version=1602937140
This entirely disables caching, since every time the page is refreshed, it will believe it needs to grab the CSS file again, changed or not... but that's far less frustrating than forgetting to manually update this trick and wasting time wondering why it isn't right. You can always remove it from a production server.
If you are using plain HTML, you could probably engineer a javascript wrapper or some such, but that's probably more trouble than it's worth.
Have you tried renaming the new version of your CSS to CSSv2.css and then directing your page to use that? If that solves the stale-file issue, then you're just experiencing non-refreshing files. If not, you've got bigger issues.
If you're using ASP.NET web forms, make sure that you are using the right theme:
I just spent about an hour trying to solve this!
Is this a local custom CSS file? Is this your website? Maybe you should clear your cache.
Also the last CSS declaration takes precedence.
I faced the same problem. Renaming the file worked for me.
The reason this occurs is because the file is stored in the "cache" of the browser – so there is no need for the browser to request the sheet again. This occurs for most files that your HTML links to – whether they're CDNs or on your server, for example, a stylesheet. A hard refresh will reload the page and send new GET requests to the server (and to external b if needed).
You can also empty the caches in most browsers with the following keyboard shortcuts.
Safari: Cmd+Alt+e
Chrome and Edge: Shift+Cmd+Delete (Mac) and Ctrl+Shift+Del (Windows)
I'm debugging on my development machine and when I make changes to the css file, they don't show up and I can't figure out why. I'm using firebug and inspecting the css and the changes are not there. I've tried clear private data and building the project first then running it but nothing seems to work.
Thanks.
Use CTL+F5 to force a full refresh -- it will force the browser to ignore anything cached.
It's probably caching your css file. Either modify your setting in the browser to stop caching, or add a unique identifier to the css file like Site.css?d=011509.