This page lists public proxy servers detected in Luxembourg. The list may be short, so it is better to treat each row as a test candidate rather than browse it like a large pool.
For a wider view, use the European proxy list and compare Luxembourg with other locations in the region.
On a small Luxembourg list, Last Checked is one of the most useful columns. A proxy checked recently is usually worth trying before an older entry, even if the older row shows a better speed value.
The protocol and port must match your software settings. Do not paste only the IP address and ignore the rest of the row. An HTTP proxy should be added as HTTP, while SOCKS entries need the matching SOCKS option.
If several Luxembourg entries are online, compare the ISP column as well. It can help you separate entries from different networks and avoid testing several rows that behave the same way.