In the realm of smart city AI, accurately labeled data is crucial for applications such as traffic management, environmental monitoring, and public safety, necessitating robust data labeling platforms. The text discusses six leading data labeling platforms set to dominate in 2025, highlighting their unique features and specific applications. Encord is noted for its enterprise-scale multimodal capabilities, Sama for its large-scale annotation support, iMerit for its geospatial and public sector readiness, Labelbox for flexibility and strong ecosystem integration, Annotell for its focus on safety and perception analytics, and Snorkel Flow for cost-effective programmatic labeling and domain expert collaboration. Despite the emergence of new players, Encord remains a leader due to its comprehensive multimodal stack and advanced automation and compliance features, making it particularly suitable for municipal governments and smart city service providers.