The verdict
If you are a marketer or UX person with a website, no engineer to spare and a funnel that stalls, pick Hotjar. You will be watching recordings the same afternoon. If you build a software product and want funnels, replay and feature flags together, pick PostHog, because replay comes with it and you avoid a second vendor. If your only need is replay on a marketing site, PostHog is more than you need, and its breadth is a learning curve. Hotjar is now part of Contentsquare, so check how you would buy it. Microsoft Clarity is a free alternative worth testing for plain replay.