What Is the HEART Framework? How Google Measures User Experience
The HEART Framework is a user experience measurement framework developed by Google researchers Kerry Rodden, Hilary Hutchinson, and Xin Fu that provides a structured approach to defining and measuring the quality of a product’s user experience at scale. HEART is an acronym for the five UX dimensions it measures: Happiness, Engagement, Adoption, Retention, and Task Success.
The framework was created to address a specific challenge in large-scale product development: how to measure user experience in a quantitative, scalable way when direct user research isn’t practical for every product change. It provides a systematic process for selecting meaningful UX metrics and connecting them to business goals.
The Five HEART Dimensions
Happiness
Happiness measures users’ subjective satisfaction and attitudes toward the product — how they feel about using it, whether they find it enjoyable, and their overall perception of its quality.
Example metrics: Net Promoter Score (NPS), customer satisfaction ratings (CSAT), ratings in app stores.
When to use: When you need to understand users’ subjective experience and whether they enjoy using the product, not just whether they can complete tasks.
Engagement
Engagement measures the level of user involvement with the product — how frequently, deeply, and broadly users interact with it.
Example metrics: Sessions per user per week, pages viewed per session, features used per session, time spent in the product.
When to use: When the goal is to understand how deeply users are using the product — whether they’re discovering and using its full value or only engaging with a narrow slice.
Adoption
Adoption measures the uptake of a product or feature — how many new users are beginning to use it.
Example metrics: New account activations, first-time feature use rate, percentage of users who have used a new feature within N days of launch.
When to use: When measuring the success of a new product launch, a significant feature release, or an onboarding initiative.
Retention
Retention measures how many users continue engaging with the product over time — the inverse of churn.
Example metrics: Day-7 and Day-30 return rates, monthly active users over time, subscription renewal rates.
When to use: When evaluating whether the product provides enough ongoing value to sustain habitual use — the fundamental indicator of product-market fit.
Task Success
Task Success measures the efficiency, effectiveness, and error rate of specific user tasks — whether users can accomplish specific goals with the product.
Example metrics: Task completion rate, time on task, error rate during task completion.
When to use: When evaluating usability quality — whether the product’s design allows users to accomplish their goals effectively.
The Goals-Signals-Metrics Framework
HEART is most powerful when combined with the Goals-Signals-Metrics (GSM) framework:
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Goals: For each HEART dimension, define specific goals. “We want users to feel confident using the product” (Happiness) or “We want users to return weekly” (Retention).
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Signals: Identify observable user behaviors or attitudes that would indicate whether the goal is being met. “Users sharing the product with colleagues” signals Happiness; “users logging in weekly without prompting” signals Retention.
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Metrics: Define specific, measurable quantities that capture the signals. NPS score for Happiness; weekly return rate for Retention.
This process produces a small, focused set of metrics aligned to specific goals — rather than a sprawling dashboard of everything that can be measured.
Applying HEART in Practice
Select the most relevant dimensions: Not all five dimensions are equally relevant for all products or all changes. A product update focused on reducing user onboarding friction might prioritize Adoption and Task Success; a study of product health might prioritize Retention and Happiness.
Measure at the right level: HEART can be applied at the product level (overall product health), feature level (evaluating a specific feature’s UX quality), or even user segment level (comparing UX quality across different user types).
Use as a communication framework: HEART provides a shared vocabulary for product, design, and engineering teams to discuss and prioritize UX quality improvements.
Key Takeaways
The HEART Framework provides a comprehensive, structured approach to measuring user experience quality that is both rigorous enough to guide product decisions and practical enough to apply at scale. By covering five distinct dimensions of user experience — from subjective satisfaction to behavioral engagement to specific task performance — it ensures that UX measurement isn’t reduced to a single metric, capturing instead the multidimensional reality of what it means to build a product that genuinely works for users.