A free web proxy is the version you use without installing anything: a page with an address box, hosted by somebody you have never heard of, that loads other pages inside itself. It is genuinely useful for one narrow job and it is routinely asked to do several it cannot, which is where almost every disappointment with them comes from.
The narrow job it does well
Loading one page, once, on a device where you cannot install software, when nothing you type into that page matters. A library computer, a locked-down work laptop, a network that blocks a site you want to read. For that, a web proxy is proportionate and effective, and the fact that it needs no account and no software is exactly the point of it.
The leaks that make it unreliable for anything else
Pages that pull content from several domains often fetch some of it directly, outside the proxy, which is why videos and embedded players so frequently fail or reveal your ordinary address. Anything using WebRTC can expose the real address from inside the browser regardless of the proxy. And nothing outside that browser tab is covered at all, so the phone app, the email client and every other tab are untouched.
The operator problem, stated plainly
The proxy fetches pages for you, so it sees every address you request and every form you submit through it. That is not a vulnerability, it is the mechanism. It means a free web proxy should be treated as a stranger reading over your shoulder: fine for a news article, wrong for a login, a payment or anything you would not paste into a public forum.
What replaces it when the job grows
The moment the requirement becomes ongoing, or covers more than one browser tab, the shape of the tool changes: a device-level VPN with a published logging policy and a price on its own page. This site exists to say what those cost and, more usefully, what they cost in year three, after the prepaid term the headline requires has run out.
Questions people ask about free web proxy
Is a free web proxy private?
Not from the operator, who fetches every page you request. It changes what the destination site sees, not what the proxy sees.
Why do some sites break in a web proxy?
Complex pages load resources from several domains, and a proxy that cannot rewrite all of them either breaks the page or lets some requests go direct.
Can a web proxy replace a VPN?
Only for reading a single page in a single browser. It covers no other application and adds no encryption between you and the destination.