Yes, free SSL certificates are widely used today, especially from Let’s Encrypt, which is trusted by all major browsers.
Modern browsers do NOT complain about SSL certificates from trusted providers like Let’s Encrypt they work just like paid ones.
Pitfalls: They expire every 90 days, so you need to renew regularly (usually automatic). Some free certificates don’t offer support or warranties.
Better alternatives: If you want cheap and reliable SSL, try
CheapSSLWeb.com they offer paid SSLs starting from $3.99/year, with site seals, warranties, and longer validity.