dbt Semantic Layer vs Looker

The dbt Semantic Layer centralizes metric definitions on dbt models and handles joins so downstream tools and applications can use metrics consistently. MetricFlow generates SQL at query time from semantic model and metric configurations. Teams define those models and metrics in YAML as version-controlled, lineage-aware code. MetricFlow can optimize joins, rewrite queries to reduce compute and latency, and cache repeated queries. The product offers an API, the dbt MCP Server and integrations for BI tools, notebooks, spreadsheets, embedded analytics and AI systems. GraphQL and JDBC APIs and a Python SDK provide ways to query metrics and dimensions; Claude and ChatGPT can connect to governed metrics through the MCP server. Documented warehouse platforms include Snowflake, BigQuery, Databricks and Redshift. Defining and querying metrics requires a dbt Starter or Enterprise-tier account, and single-tenant accounts need account-representative setup and enablement. Starter includes 5,000 queried metrics per month; Enterprise and Enterprise+ each include 20,000. Starter costs $100 a month per user. The free Developer plan does not list the Semantic Layer.

Looker helps organizations explore, share, and visualize company data for business decisions. Its LookML semantic models define dimensions, aggregates, calculations, and relationships, then use those definitions to generate SQL queries. Gemini-powered natural-language analytics lets users ask questions, while Dashboard Agents provide summaries and explorations grounded in governed metrics. Looker connects to BigQuery, Spanner, Cloud SQL for MySQL, Cloud SQL for PostgreSQL, and other Google services. The Looker Marketplace offers applications, prebuilt LookML models, visualizations, and actions for delivering data to third-party services. Listed capabilities include hourly refresh, row-level security, scheduled reports, and embedded analytics. Deployment is hybrid, with web, Android, iOS, API, and self-hosted options. Mobile apps let users view Looks and dashboards. Google documents TLS 1.2 or later for data in transit and AES-256 encryption for locally stored sensitive application data. A free 14-day trial is advertised, but there is no free plan. Standard, Enterprise, and Embed each list one production instance, 10 Standard Users, and two Developer Users; their API call allowances differ. Pricing is on request.