The conversion itself, apparently, works.
BUT when it comes to click on the Download button, the site repeatedly opens a series of popup Windows, ending with a fake antivirus window (i don't have such brand of antivirus installed on my computer!) saying that a virus has been detected. Then, smart evil, it invites you to click on a button to "return and avoid the threat": this button has an obscure address, possibly redirecting to a harmful site.
Without your permission, by means of maybe some invisible hotpoint in whatever web page, they charge 5.00 €, automatically, every month.
Don't know whether harmful for your PC, surely it is for your wallet.
It pretends to be some kind of virus control, and claims that you are affected by some viruses, and invites to click on "PROCEED". If you close that windows, it pops up some additional pop-up windows. I closed all the windows only by clicking on "x" on top right of each window.
BTW, in seconds, my Win10 Defender detected a Trojan:Win32/CoinMiner, classified at high risk, then advised to remove all.