Prolific records 18,697,671 monthly visits with -1.8% month-over-month growth and Paid pricing. Sieve records 124 monthly visits with +1.6% growth and Contact for Pricing pricing.
High-quality human data for AI training, evaluation, and research
The data lab for real-world intelligence
| Dimension / Metric | ||
|---|---|---|
| Official Domain | prolific.com | sievedata.com |
| Pricing Model | Paid | Contact for Pricing |
| Monthly Visits | 18.7M (18,697,671) | 124 (124) |
| MoM Traffic Delta | -352.04K (-1.8%) | +2 (+1.6%) |
| Primary Market & Share | 🇺🇸 United States (48.8%) | 🌐 Global (—) |
| Direct Visits / mo | 12.98M | 54 |
| User Rating | 4.6 | 4.1 |
| Supported Platforms | Website | Website |
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.
The data lab for real-world intelligence
First-person recordings of economically valuable physical work, paired with hand-pose, motion and synchronised sensor annotations.
Multi-camera video and audio collection with bespoke rigs and controlled environments built to a client's specification.
Both simulated and real-world test suites that measure how well robot policies perform across tasks and conditions.
Petabyte-scale synchronised video and audio datasets, including published engineering work on embedding a billion videos for retrieval.
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-sourceBuild, train, and deploy computer vision for the physical world
Free / Open-sourceBuild, train, and deploy computer vision for the physical world
Free / Open-sourceReal-time image and video APIs, agentic DAM and creative automation in one platform
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.
The data, evaluations and systems behind AI that has to be right.
Free / Open-sourceAI data infrastructure for building production-grade models
Free / Open-sourceAI data infrastructure for building production-grade models
Free / Open-sourceMulti-modal AI detection API that flags synthetic images, text, audio, video and deepfakes
Free / Open-sourceMulti-modal AI detection API that flags synthetic images, text, audio, video and deepfakes
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.
The multimodal data layer for computer vision and physical AI teams
Free / Open-sourceOne universal API for 500+ AI models and 1,000+ agentic tools
