Prolific records 18,697,671 monthly visits with -1.8% month-over-month growth and Paid pricing. Sider records 2,644,740 monthly visits with -10.6% growth and Freemium pricing.
High-quality human data for AI training, evaluation, and research
AI sidebar and browser agent for reading, writing and research
| Dimension / Metric | ||
|---|---|---|
| Official Domain | prolific.com | sider.ai |
| Pricing Model | Paid | Freemium |
| Monthly Visits | 18.7M (18,697,671) | 2.64M (2,644,740) |
| MoM Traffic Delta | -352.04K (-1.8%) | -314.2K (-10.6%) |
| Primary Market & Share | 🇺🇸 United States (48.8%) | 🇺🇸 United States (13.3%) |
| Direct Visits / mo | 12.98M | 1.7M |
| User Rating | 4.6 | 4.5 |
| 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.
AI sidebar and browser agent for reading, writing and research
A persistent panel that reads the page you are on and answers follow-ups with GPT, Claude or Gemini without copying content into another tab.
Summarise long articles, PDFs and YouTube videos, extract key points, and ask detailed questions about the source material.
Translate webpages, PDFs and images, compare bilingual output side by side, and have content read aloud for review on the move.
Delegate multi-step tasks across real websites — price comparison, form filling, research and inbox triage — using your existing logged-in sessions.
SpecialistOpenAI's flagship multimodal assistant powered by GPT-6 and GPT-5.6 for reasoning, coding, and deep research.
SpecialistOpenAI's flagship multimodal assistant powered by GPT-6 and GPT-5.6 for reasoning, coding, and deep research.
SpecialistAnthropic's frontier AI workspace powered by Claude 5.5 for agentic coding, analysis, and nuanced writing.
SpecialistAnthropic's frontier AI workspace powered by Claude 5.5 for agentic coding, analysis, and nuanced writing.
Offers a very similar browser sidebar experience with multiple AI models, but features slightly different pricing and workspace tools.
Offers a very similar browser sidebar experience with multiple AI models, but features slightly different pricing and workspace tools.
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.
Provides robust browser-based summarization and prompt assistance, but lacks some of Sider's deeply integrated multi-model chat UI features.
Provides robust browser-based summarization and prompt assistance, but lacks some of Sider's deeply integrated multi-model chat UI features.
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.
Excels at advanced web automation and data extraction alongside chat, but has a steeper learning curve than Sider.
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.
Free / Open-sourceSummarize YouTube, Google, and any page with AI — free in your browser
Free / Open-sourceSummarize YouTube, Google, and any page with AI — free in your browser
