Pika positions itself around speed and accessibility — the UI is the simplest in the category, generations come back fast, and the per-clip cost is the cheapest among the major models. For social-first creators iterating dozens of ideas a day, that loop matters more than absolute fidelity.
Runway is the production tier. Motion brush, image-to-video, camera controls, and a more mature timeline make it the answer when each shot matters and you'll iterate on it in earnest. The price gap is real — Runway's API at ~$0.50/sec is multiples of Pika's per-clip economics — but for finished work, the quality usually justifies it.
Use the video generation cost calculator to model your actual volume against both.