es.bab.la is a dictionary and language translation site that has been around since at least 2008. That kind of longevity usually suggests a legitimate operation, and the site does pass basic security checks. But when you're using a service regularly for translations or language learning, you want to know who's behind it and how your data is handled.
Here's where this site falls short: there is no contact information, no about page, no privacy policy, and no terms of service. For a commercial website that almost certainly serves users in Europe, those are standard legal requirements. The WHOIS record for the domain doesn't exist, so even the basic registration details are hidden.
Does that make es.bab.la a scam? Not necessarily. The site works as a dictionary and has been online for years. But the lack of transparency means there's no way to reach them if something goes wrong, and no clear promise about what happens to any data you enter. If you're just looking up a word or two, the risk is minimal. But I wouldn't create an account or enter personal information here, and I'd look for a more transparent alternative for regular use.