LocalCDN is a web browser extension for your Firefox that emulates CDNs (Content Delivery Networks). It intercepts the network traffic between a website and remote CDNs, finds supported resources locally, and injects them into the environment. All of this happens automatically, so no prior configuration is required.
For more information, please read this basic introduction from Decentraleyes or our Wiki pages.
In most cases LocalCDN can easily replace embedded frameworks and improves privacy. In some cases the website may try to prevent this by setting certain options in the HTML source code. LocalCDN reads the HTML source code before it is displayed in the browser and removes these options.
Unfortunately, it sometimes happens that special characters are then displayed incorrectly. In this case you can deactivate the setting again, to display the umlauts correctly.
This is caused by a policy of the same origin and is a security mechanism that determines what data the browser is allowed to load. It helps to isolate malicious documents and thus reduce possible attack vectors. This policy prevents the browser from loading the external frameworks of LocalCDN.
If the layout of a website is incorrect or cannot be operated, then it is usually due to this policy, even though the add-on works flawlessly. Unfortunately there is no solution for this at the moment.