1. Pricing Model: Lookback offers a pay-per-study pricing model, allowing users to purchase individual studies as needed, while UserTesting provides subscription-based pricing options for unlimited studies, making it a more cost-effective choice for frequent users.
2. Participant Recruitment: Lookback relies on user recruitment through its own panel, whereas UserTesting taps into a vast network of pre-screened participants for quick and efficient recruitment.
3. Live Moderation: Lookback allows for live moderation during research sessions, enabling direct interaction with participants, whereas UserTesting is more focused on unmoderated remote testing, allowing for a more hands-off approach.
4. Features and Integration: Lookback provides a robust set of features for in-depth analysis of research sessions but may require additional integrations for full functionality, while UserTesting offers a more streamlined experience with built-in features and integrations.
5. Support and Training: Lookback offers more personalized support and training options for users, ensuring a smoother onboarding process, whereas UserTesting provides extensive resources and documentation for self-guided learning.
6. Target Audience and Use Cases: Lookback caters more towards UX professionals and design teams for detailed user research projects, whereas UserTesting is suitable for a wider range of users, including marketers, product managers, and UX designers, for quick feedback on web and app usability.

In Summary, Lookback and UserTesting differ in pricing models, participant recruitment methods, live moderation capabilities, features and integration options, support and training offerings, as well as target audience and use cases.