Defined.ai records 146,251 monthly visits with -21% month-over-month growth and Contact for Pricing pricing. Prolific records 18,697,671 monthly visits with -1.8% growth and Paid pricing.
Enterprise AI training data, annotation and evaluation services
High-quality human data for AI training, evaluation, and research
| Dimension / Metric | ||
|---|---|---|
| Official Domain | definedcrowd.com | prolific.com |
| Pricing Model | Contact for Pricing | Paid |
| Monthly Visits | 146.25K (146,251) | 18.7M (18,697,671) |
| MoM Traffic Delta | -38.82K (-21%) | -352.04K (-1.8%) |
| Primary Market & Share | 🇺🇸 United States (20.6%) | 🇺🇸 United States (48.8%) |
| Direct Visits / mo | 84.42K | 12.98M |
| User Rating | 4.4 | 4.6 |
| Supported Platforms | Website | Website |
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.
High-quality human data for AI training, evaluation, and research
Filter participants by detailed demographic, professional, and behavioural criteria and reach narrow or representative samples rather than a generic crowd.
Collect human preference data for model fine-tuning, run safety evaluations and red-teaming, and use a feedback API to plug humans into automated pipelines.
Attention checks, honesty screening, and approval workflows help filter out careless or fraudulent responses before you analyse results.
Publish a study and begin collecting responses quickly, with tooling that supports screening, quotas, and longitudinal designs.
Large consumer panel for market research surveys, but lacks Prolific's specialized focus on academic studies and AI tuning.
Large consumer panel for market research surveys, but lacks Prolific's specialized focus on academic studies and AI tuning.
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.
SpecialistWeb data infrastructure for scraping, proxies, and AI-ready datasets
SpecialistWeb data infrastructure for scraping, proxies, and AI-ready datasets
SpecialistThe environments frontier AI trains on, and the agents that do the recurring work
SpecialistThe environments frontier AI trains on, and the agents that do the recurring work
Enterprise-grade data annotation and AI alignment workforce, but less self-serve for academic study recruitment and casual surveys.
SpecialistAI data infrastructure for building production-grade models
SpecialistAI data infrastructure for building production-grade models
SpecialistSpecializes in video-based consumer interviews and AI qualitative analysis, but less focused on quantitative academic survey panels.
SpecialistSpecializes in video-based consumer interviews and AI qualitative analysis, but less focused on quantitative academic survey panels.
SpecialistSources verified B2B professionals and healthcare experts for specialized research, but lacks broad general-population academic panels.
SpecialistSources verified B2B professionals and healthcare experts for specialized research, but lacks broad general-population academic panels.
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 for AI workflows, but requires bringing your own annotation workforce.
Free / Open-sourceOpen-source data labeling and evaluation platform for AI workflows, but requires bringing your own annotation workforce.
