Is there a free LMS, and what's the catch?

Yes, but "free" comes in two flavours, each with a catch:

• Open-source (e.g. Moodle) — the software is free, but you pay in hosting, maintenance, and IT time. For a team without technical staff, that hidden cost is real.
• Free tiers from cloud vendors — genuinely free, but capped (often 5–10 users and a handful of courses, with premium features locked). Great to start, but you'll hit the ceiling as you grow.

A free tier is the smart way to begin: prove the value, train a pilot group, then upgrade when you outgrow the limits. The mistake is choosing "free" without counting the full cost — a free open-source LMS that needs a server and a sysadmin can cost more than a paid cloud plan.

Start free, but choose a platform whose paid plans are affordable and transparent, so growing doesn't mean a painful migration later.