How do online proxies like https://www.hidemyass-freeproxy.com/ work? I'm looking for a backend agnostic explanation.
I have the following idea on how they work but there are some gaps in my thought process:
- User wants to visit google.com, so "google.com" is sent as value of e.g. X-Proxy-Url header to a proxy server
- Proxy then makes it's magic, returning the HTML of google.com back to the user
- When proxy returns the proxied website, any links in this proxied google.com have been replaced with special links to the proxy server, to proxy further requests.
Is the above correct? If yes, here are my further questions.
- If proxy makes a request on behalf of the user to google.com, does it not get blocked like a typical web scraper?
- How does it handle all the related assets like CSS, images, fonts, etc so that they go through proxy as well? OR do they not go through proxy?
- How does it handle all the links in the proxied google.com website so that those links go through proxy as well? I investigated this on my own and seems like it replaces all the links with special links that point back to the proxy.