The site works fairly well and the files you download have no problems as far as I can tell. However, I did get some malware hits on web files and other related programs, likely meant to redirect you from their main search page.
It's very good mp4 to mp3 converter and one of the best music search engines. But when downloading, some useless sites are opening. sometimes they are not suitable for children. so parental attention is advised.
URL Scanner Result
Quttera Malicious site
Status: Outdated Software detected. Immediate Action is Recommended.
Website Firewall Not Found Medium Risk Patch and Protect
Website Outdated Detected High Patch and Protect
ISSUE DETECTED DEFINITION VULNERABLE HEADER
Outdated Web Server Nginx Found Vulnerabilities on nginx nginx/1.2.1