Defined.ai: Offers pre-packaged AI training datasets and custom data collection services, but with a smaller global crowd than Appen. Appen records 665,840 monthly visits with +0.2% month-over-month growth and Contact for Pricing pricing. Defined.ai records 146,251 monthly visits with -21% growth and Contact for Pricing pricing.
Human-validated training data and evaluation services for frontier AI models
Enterprise AI training data, annotation and evaluation services
| Dimension / Metric | | |
|---|---|---|
| Official Domain | appen.com | definedcrowd.com |
| Pricing Model | Contact for Pricing | Contact for Pricing |
| Monthly Visits | 665.84K (665,840) | 146.25K (146,251) |
| MoM Traffic Delta | +1.1K (+0.2%) | -38.82K (-21%) |
| Primary Market & Share | 🇺🇸 United States (22%) | 🇺🇸 United States (20.6%) |
| Direct Visits / mo | 238.31K | 84.42K |
| User Rating | 4.4 | 4.4 |
| Supported Platforms | Website | Website |
Human-validated training data and evaluation services for frontier AI models
Chain-of-thought reasoning traces, SME-level RLHF, supervised fine-tuning demonstrations and adversarial red teaming for the most capable models.
Golden trajectories, RL environment design, failure-mode taxonomies and software-engineering-driven deep evaluation for autonomous agents.
Multilingual ASR and conversational speech data, expressive TTS annotation, vision-language model training data, video action labelling and voice-agent evaluation.
LiDAR point-cloud labeling, multi-camera sensor fusion, robot demonstration trajectories, world-model rollouts and embodied interaction logs.
Enterprise AI training data, annotation and evaluation services
A large selection of ready-to-use, ethically sourced datasets across audio, image, video, text and multimodal formats, with advanced filtering and free samples.
Expert-verified labeling for text, audio, image and video using model-first, human-in-the-loop workflows for accuracy and fairness.
High-quality multilingual content for global AI systems, drawing on 500+ languages, dialects and locales.
Global, diverse data collection at scale for training, with privacy and security vetting on every dataset.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.
SpecialistConnects teams directly with verified human participants for preference tuning and studies, but lacks managed end-to-end labeling pipelines.
Free / Open-sourceOpen-source model and dataset hub with one-click online demos
Free / Open-sourceOpen-source model and dataset hub with one-click online demos
Free / Open-sourceStreamlines computer vision dataset annotation and model deployment, but lacks the broad human crowd-sourcing services of Defined.ai.
Free / Open-sourceStreamlines computer vision dataset annotation and model deployment, but lacks the broad human crowd-sourcing services of Defined.ai.
Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.
Blends custom software with dedicated human expert teams to handle complex operations, but operates as a bespoke service.
SpecialistWeb data infrastructure for scraping, proxies, and AI-ready datasets
SpecialistWeb data infrastructure for scraping, proxies, and AI-ready datasets
Comprehensive enterprise data labeling platform with powerful automation agents, but carries significant pricing overhead for smaller teams.
Comprehensive enterprise data labeling platform with powerful automation agents, but carries significant pricing overhead for smaller teams.
Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing.
Provides enterprise-grade AI training data and model evaluation at massive scale, but often with higher enterprise pricing.
Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks.
Delivers advanced multimodal data curation and annotation infrastructure, but requires your own annotation workforce for labeling tasks.
SpecialistAgent observability, evaluation, and continuous improvement for production AI
SpecialistAgent observability, evaluation, and continuous improvement for production AI
Advanced multimodal data infrastructure for computer vision teams, though specialized primarily in video and image annotation.
Advanced multimodal data infrastructure for computer vision teams, though specialized primarily in video and image annotation.
Free / Open-sourceOpen-source data labeling and evaluation platform offering full self-hosting control, but requires manual setup and infrastructure maintenance.
Free / Open-sourceOpen-source data labeling and evaluation platform offering full self-hosting control, but requires manual setup and infrastructure maintenance.
Provides expert human workforce for AI training and evaluation datasets, though with fewer automated labeling tools.
Provides expert human workforce for AI training and evaluation datasets, though with fewer automated labeling tools.
