A browser's cache is a way for a web browser (Chrome, Safari, Firefox) to store information about you and the website you are visiting locally, speeding up login and loading processes. Unfortunately, this can occasionally cause issues when the files saved are different than the ones updated online and often, this causes issues with logging in or accessing certains pages.
An easy thing to test when a website is no longer working is to clear the cache. Below are some steps on how to do that.
How To Clear Cache In Google Chrome - Deleting Browser Cache
On your computer, open Chrome.
At the top right, click More More and then Clear browsing data.
Select a time range, All time.
Select the Cookies and other site data
Click Clear data.
How To Clear Cookies & Cache on Chrome (Android)
On your iPhone or iPad, open Chrome .
Tap More Delete Browsing Data.
Choose the types of information you want to remove.
Tap Delete Browsing Data.
In the popup window, tap Clear Browsing Data.
At the top right, tap Done.
How to Clear Cache in Firefox Browser
In the Menu bar at the top of the screen, click Firefox and then select Preferences or Settings, depending on your macOS version.
Select the Privacy & Security panel.
In the Cookies and Site Data section, click Clear Data….
Remove the check mark in front of Cookies and Site Data.
For more information about managing site data, see Manage local site storage settings.
With Cached Web Content check marked, click the Clear button.
Close the Settings page. Any changes you've made will automatically be saved.
How to Clear Cache and Cookies in Mozilla Firefox on iPhone
At the bottom of the screen, tap the menu button (the menu will be at the top right if you're using an iPad)
Select History on the panel to see your visited sites.
Tap the trash icon in the bottom left corner.
Choose from the following timeframes to clear:
Today
Today and Yesterday
Everything
How To Clear Cache In Safari - Video
Click on the Safari drop-down menu and select Preferences.
Click the Advanced tab. Select the Show Develop menu in menu bar checkbox and close the Preferences window.
Select the Develop drop-down menu. Click Empty Cache.
Note: You may want to also clear your browser history. Select the History drop-down, then Clear History.
How to Clear Safari Cache on iPhone
Go to Settings > Safari > Advanced > Website Data.
Tap Remove All Website Data.
Reference: https://support.apple.com/en-hk/105082