Start with the input you actually have. Text-to-video models (Runway, Kling, Luma, Pika) generate scenes from prompts and suit B-roll, intros, and concept clips. Image-to-video starts from a still you control, which gives far more consistent branding — the better choice for product shots and recurring characters. Avatar generators are a different category entirely and live in their own hub.

Output quality is only half the story. Check clip length per generation, how motion holds up past five seconds, and the credit system: a cheap plan that burns credits on failed generations is not cheap. Watermarks on free tiers, commercial-use rights, and whether your uploads train the model all belong in the decision.

Our generator reviews run the same prompts through every tool so results are comparable. See the full field in Best AI Video Generators, then the individual reviews: Runway, Kling, Luma Dream Machine, and Pika.