A free proxy server is a machine somebody else pays to run, which is the first fact worth sitting with. Bandwidth, addresses and hardware all cost money, so a service given away is being funded some other way, and on this particular shelf the funding model is almost never printed anywhere. That is the difference between a free proxy and a free tier from a company that also sells something.
The three ways free proxies are funded
Advertising injected into the pages you load is the visible one. Logging and selling browsing data is the second, and it is invisible from the outside. The third is bandwidth resale, where your connection is used as an exit for somebody else's traffic, which is how several free products have historically worked and which is a genuinely serious thing to agree to unknowingly. None of the three is announced on the sort of page that offers a free proxy list.
What to expect operationally
Free proxy lists go stale quickly: an address that worked yesterday times out today, speeds vary between poor and unusable, and the busy ones are already blocked by the services people want to use them for. This is not a complaint about quality so much as a description of the category. If a proxy needs to work reliably at a particular moment, a free one is the wrong tool.
The free tier alternative, which is a different thing
Three providers in this price index publish a free plan on their own site with the limits written down: hide.me lists a free plan with restricted speeds, eight locations and one connection, Windscribe publishes a build-a-plan tier starting at zero, and Proton VPN maintains a dedicated free page. Those are free products from companies whose business model is the paid plan beside them, which is a materially different proposition from an anonymous proxy list.
What the paid end costs, for comparison
The cheap end of this index is genuinely cheap, and the priced table shows how little separates it. The catch is the same everywhere: the headline is an intro rate that requires a prepayment of two to three years, and the renewal beside it is the standing price. That trade is at least stated on the page, which is more than a free proxy server offers.
Questions people ask about free proxy server
Is a free proxy server safe?
The operator sees your traffic and most publish nothing about what they retain or how they are funded. Assume anything you send through one is visible.
Why is my free proxy so slow?
Free proxies are heavily shared and often rate-limited. Popular ones are also blocked by the services people most want to reach through them.
Is a free VPN tier better?
It is at least accountable: hide.me, Windscribe and Proton VPN publish their free plans and the limits on their own sites, beside a paid plan that funds them.