Plenty of providers in this series give away a proxy checker. Unknown Proxies gives away a HAR analyser, and that tells you who built it.

Why the HAR Analyser Is the Standout

A HAR file is a complete record of everything your browser did loading a page. Every request, every response, every header, every timing.

When a proxy setup fails in a way you cannot explain, the HAR file is where the answer lives. Which request went out unproxied. Which header gave you away. Where the time actually went.

Reading one by hand is miserable. A tool that parses it and shows you what happened turns an afternoon of squinting into a few minutes.

Nobody builds that unless they have personally spent afternoons squinting. It is the strongest signal in this whole catalogue about who is behind the company.

The Rest of the Toolkit

A data usage calculator, which answers the question people get wrong most often: how many gigabytes will this job actually consume. Guess low and you run out mid run. Guess high and you overbuy.

A delay calculator for working out request pacing, which is the difference between collecting data and getting rate limited.

A user agent checker and a converter, plus a browser extension.

We maintain a user agent checker and a proxy checker ourselves for exactly this reason. Tools like these exist because the same questions arrive a hundred times, and building the answer is kinder than typing it repeatedly.

The Products

Residential addresses priced per gigabyte at the premium end of this market, and ISP addresses priced per address at a much lower rate.

That residential pricing is high, and it is worth being straight about. The positioning is uncompromising quality with 99.9% uptime and unmatched support, and they describe themselves as the broker's choice for speed and reliability.

Premium pricing only makes sense if the success rate justifies it. Measure cost per successful request rather than cost per gigabyte, because a cheap address that fails half the time is the expensive one.

Queue Without Interruptions

One stated feature is joining a queue without interruptions, which points at high demand release work where being dropped mid queue is the entire failure mode.

That is among the most demanding uses there is, and building for it requires quality general scraping would never need.

Who It Fits

Unknown Proxies suits queue and release work where reliability outweighs price, anyone who needs to debug a proxy setup properly, users who want ISP addresses at a fair per address rate, and people who value good free tooling.

Who Might Look Elsewhere

Bulk collection on tolerant targets does not need premium pricing. A cheaper residential provider will serve you better.

There is no dedicated mobile carrier tier.

Final Verdict

Unknown Proxies is a quality first specialist with the best free toolkit in this entire series.

Residential and ISP addresses, a stated focus on reliability over price, and a set of diagnostic tools that includes things nobody else thought to build.

Use the tools before you buy anything, from them or anyone else. The data usage calculator alone will change how much you purchase.