Many sites offer free proxies, but how do these businesses get their money? They make you into a product. Most free proxy networks are known to harvest users’ data and insert malicious code. If you want to stay safe online, choose a trusted US proxy network.
But, you can always play with some free trials companies!!! 
- https://www.localproxies.com/#pricing
- https://luminati.io/proxy-networks/residential-ips <<< 7 days free trial after registration! But you have to complete KYC authentication to test their residential IP proxies.
- https://www.scraperapi.com/
https://monkeysocks.net/ <<< if you needed for the short time. - https://www.proxyrotator.com/free-proxy-list/
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