Contents
1. Encord – End-to-End Multimodal Platform
2. Sama – Scale, Quality & Multimodal Depth
3. iMerit – Geospatial & Public Sector Ready
4. Labelbox – Flexible & Multimodal with Strong Ecosystem Integration
5. Annotell – Safety / Perception Analytics Specialty
6. Snorkel Flow (Snorkel AI) – Programmatic Labeling & SME Collaboration
Choosing the Right Data Labeling Platform
Why Encord Still Leads (Even Among New Players)
Encord Blog
6 Best Data Labeling Platforms for Smart Cities AI [2025]

AI is transforming smart cities, from real-time traffic management and environmental sensing to public safety, infrastructure monitoring, and citizen services. But even the most advanced urban AI systems depend on accurately labeled data.
High-quality labeled training data is essential in smart city deployments where stakes are high, and data is multimodal: video, satellite, aerial imagery, LiDAR, sensor data, etc.
In smart cities, AI relies on:
- Video from traffic cameras, CCTV, and public safety monitoring
- LiDAR, radar and 3D point clouds for mapping infrastructure, autonomous transit, obstacle detection
- IoT sensor and telemetry data from water, energy, air quality, sound, waste etc.
- GIS / geospatial / satellite/aerial imagery for planning, zoning, land use, flood risk
- Anomaly detection for utilities, environment, structural health, etc.
Choosing the right data labeling platform is critical. Here are the top 6 platforms for smart city AI in 2025, including some newer names.
1. Encord – End-to-End Multimodal Platform
Encord remains strong for enterprise-scale, multimodal workflows. It supports video, LiDAR, sensors, images, etc., making it suitable for traffic flows, infrastructure monitoring, and public safety applications in the city.
Key features:
- Annotate video, LiDAR, 3D, images + text/audio. The platform is also video-native, making it ideal for computer vision applications
- Automation to help with repetitive frame interpolation, motion tracking and SAM 2 integration for faster labeling
- Workflow management: QA dashboards, role-based access, collaboration, monitoring for enhanced visibility and observability across enterprise-grade AI teams
- Strong compliance: GDPR, SOC2 etc., which is critical for public sector data
Best for: Municipal governments, integrators, smart city service providers needing a full data ops stack.
2. Sama – Scale, Quality & Multimodal Depth
Sama has expanded its features recently, adding better LiDAR / 3D support, plus enhanced tooling for annotating large scale, complex multimodal data.
Key features:
- Very high throughput that allows for hundreds of millions of frames or annotation shapes per month
- Strong quality assurance and human-in-the-loop processes for catching edge cases, sensor errors etc.
- Multimodal support (video, images, LiDAR), with capabilities to handle sensor fusion tasks
- Reporting / dashboards for monitoring quality and progress
Best for: Cities and agencies needing reliable, large-scale annotation for multimodal systems, especially safety-critical ones.
3. iMerit – Geospatial & Public Sector Ready
iMerit is a newer consolidated platform that brings together automation, annotation tools, and analytics. Strong credentials in geospatial work, public sector, and domains where data privacy and domain expertise matter.
Key features:
- Handles image, video, LiDAR, sensor fusion, and geospatial / remote sensing imagery.
- Workflow automation + analytics, with QA and reporting.
- Strong public sector / government credentials (secure offices, compliance) and experience.
- Domain specialists / subject matter experts in geospatial imagery and mapping.
Best for: Urban planning agencies, mapping departments, municipalities needing precision in GIS / aerial imagery, and secure public data handling.
4. Labelbox – Flexible & Multimodal with Strong Ecosystem Integration
Labelbox has matured a lot, and is widely used across industries including those relevant to smart city applications. Its feature set supports many modalities and use cases.
Key features:
- Supports image, video, audio, geospatial tiled imagery, documents etc.
- Good tooling for segmentation, object detection, classification; well‐designed annotation interfaces and integrations.
- Strong for teams that want a mix of managed service + self-serve tooling.
Good presence / support in Europe (useful for GDPR, local compliance).
Best for: Municipal AI/ML teams wanting a flexible platform that can adapt as their needs grow, especially where different data types are involved.
5. Annotell – Safety / Perception Analytics Specialty
Annotell is more specialized, but its strengths map well onto smart city perception problems (e.g. pedestrian detection, traffic, autonomous transit).
Key features:
- Strong video annotation, perception analytics; tools that help measure dataset quality and object detectability under different conditions.
- Keyframe interpolation, support for temporal coherence (useful for moving objects in traffic scenes etc.)
- Ability to connect sensor data to ground truth for safety/perception evaluation.
Best for: Smart mobility, autonomous transit, traffic analysis, intersections, any application where moving objects and detection under variable conditions matter.
6. Snorkel Flow (Snorkel AI) – Programmatic Labeling & SME Collaboration
For many smart city problems (e.g. anomaly detection, sensor fusion, monitoring), labeling can get expensive; programmatic or semi-automated labeling helps. Snorkel’s “Flow” product is strong here.
Key features:
- Labeling functions for automating parts of the labeling task (e.g. pattern matching, embeddings, keyword or feature-based rules) instead of doing everything manually.
- Tools for collaboration between domain experts / SMEs + data scientists. Good for ensuring labels capture domain nuance (e.g. what is “road obstruction”, “public safety breach”, “infrastructure damage”).
- Error / conflict detection & analysis; helps in iterating and improving label quality.
Best for: Budget-sensitive city projects, R&D / pilot projects, or where you have SMEs who can encode domain knowledge, but need to scale labeling more efficiently.
Choosing the Right Data Labeling Platform
Use Case | Recommended Platform |
Large scale multimodal infrastructure + transit + public safety | Sama or Encord |
Geospatial / aerial / mapping + city planning + public sector requirements | iMerit |
Traffic, moving objects, perception, safety thresholds | Annotell |
Mixed data types, sensor + video + documents + audio | Labelbox |
Pilot / R&D / budget limited but needing domain expertise | Snorkel Flow |
Need full data ops + compliance + governance | Encord or iMerit |
Why Encord Still Leads (Even Among New Players)
While these new players bring compelling strengths, Encord continues to be a top contender in smart city AI because it provides:
- A truly multimodal stack: video, images, LiDAR, sensors, GIS etc.
- Strong tools for automation of repetitive tasks (frame interpolation, pre-labeling) + edge case detection.
- Workflow & dataset management with quality tracking, dashboards, role separation.
- Enterprise-grade governance and compliance capabilities (important for public sector, privacy, safety).
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