TL;DR
YouTube gets blocked through DNS filtering, firewalls, or country-level restrictions. Free "unblocked YouTube" mirror sites fetch videos on your behalf, but they're unreliable and often loaded with ads. A proxy routes your own connection through a clean IP instead. Residential proxies work best since they blend in with normal household traffic.
Why YouTube Gets Blocked

Most blocks happen through DNS filtering: the network checks the domain against a blocklist before the request reaches YouTube. If youtube.com falls under "video" or "entertainment," the filter refuses to resolve it. IBM notes this applies to the whole domain, not individual pages. Some networks inspect traffic itself at the firewall level. In certain countries, YouTube is blocked entirely, sometimes for long stretches, part of a documented history of YouTube censorship worldwide.
Mirror Sites vs a Real Proxy

An unblocked YouTube site is usually a mirror page: paste a link, it fetches the video, and streams it back so your device never talks to YouTube directly. The catch is reliability. Filters catch up to mirrors fast, and many run intrusive ads or unverified scripts.
A dedicated proxy fixes this properly. Instead of depending on someone else's mirror, Proxyon routes your traffic through a clean IP the filter has no reason to flag, set up once in your browser or system settings.
Also Read: How to Use a Proxy Server on Any Device
Choosing the Right Proxy

Residential proxies work best here. They use IPs tied to real ISPs and households, so they blend in instead of standing out. Datacenter proxies are cheaper, but stricter filters often blocklist known datacenter ranges already. Proxyon covers residential IPs across 195 countries, useful for YouTube content tied to a specific region.
Also Read: What is Geo-Targeting With Residential Proxies
FAQ Section

Is it legal to use unblocked YouTube sites?
Yes, but a workaround can still violate your network's acceptable use policy.
Why do free unblocked YouTube sites stop working?
They reuse similar hosting patterns, so filters flag the rest once one is caught.
Do I need a VPN or a proxy?
A VPN encrypts your whole connection. A proxy only routes what you point at it, which is enough for browser-based access.
Will a proxy slow down streaming?
Not with enough bandwidth. Free or overloaded proxies often add lag at higher resolutions.
Can schools or workplaces detect proxy use?
Some can, if they inspect traffic patterns closely.
What's the difference between a proxy and a mirror site?
A mirror fetches content for you. A proxy routes your own connection through a different IP so you reach YouTube directly.
Final Thoughts
Free unblocked YouTube sites work as a short-term fix, but they're unreliable and come with real privacy trade-offs. A dedicated proxy gets you consistent access without depending on a mirror that might disappear tomorrow. Residential proxies are the better pick when a network is actively filtering by IP type.