# Prolific vs Scale

Prolific records 77,755 monthly visits with -24% month-over-month growth and Paid pricing. Scale records 616,915 monthly visits with +12.5% growth and Contact for Pricing pricing.

| Metric | [Prolific](https://openaitools.app/tool/prolific-co) | [Scale](https://openaitools.app/tool/scale) |
| :--- | :--- | :--- |
| Website URL | https://prolific.co | https://scale.com |
| Categories | AI Research Tool, AI Developer Tools, AI For Data Analytics | AI Developer Tools, Large Language Models (LLMs), AI Models, AI Agent |
| Pricing Model | Paid | Contact for Pricing |
| Monthly Visits | 77,755 | 616,915 |
| MoM Growth Rate | -24% | +12.5% |
| Primary Market | United Kingdom | United States |
| Direct Visits | 62,154 | 191,408 |
| Review Score | 4.7 | 4.7 |
| Saved Count | 1 | 3 |
| Supported Platforms | Website | Website |

## Prolific

Prolific started as an academic survey recruitment tool and has grown into one of the most widely cited sources of high-quality human data for AI development. Its core promise is representative, well-screened participants who sign up specifically to take part in paid studies, rather than a passive panel that ignores requests. Researchers pay per response, which makes budgeting and sample sizing straightforward.

On the AI side, Prolific positions itself around preference tuning, safety evaluations, and defensible benchmarks. The company publishes the HUMAINE framework for human-preference evaluation of large language models and maintains a leaderboard, alongside data products aimed at examining model behaviour with real human feedback from populations in many countries. For classic research, the platform supports academic studies, market and product research, audience finders, and managed services where Prolific helps source specialist cohorts such as healthcare or coding experts.

Prolific also operates the participant side of the marketplace: people sign up, are verified, and get paid to take studies on a flexible schedule. For builders, there are APIs and integrations that let teams pull human feedback directly into their evaluation pipelines.

**Pricing & Plans:** Freemium-style access: signing up and building studies is free, and customers pay per completed response at a rate they set (plus a platform fee). AI and enterprise teams can also use the Human Feedback API and managed services, with custom pricing available through sales.

- **Verified global participant pool:** Access hundreds of thousands of vetted participants across 40+ countries, with demographic screening so you can target the exact population your study or evaluation needs.
- **AI preference tuning and safety evals:** Purpose-built workflows for collecting human preference judgments, red-teaming feedback, and benchmark ratings for large language and multimodal models.
- **Human Feedback API and MCP:** Programmatic access that lets engineering teams pipe real human feedback into model evaluation and agent workflows without leaving their own tooling.
- **Fast turnaround and sample control:** Launch a study in minutes, set quotas and reward levels, and scale sample sizes up or down while keeping response quality consistent.
- **Data-quality tooling:** Attention checks, prescreening, and platform-level anti-fraud measures help keep responses trustworthy and reproducible across runs.

**Strengths:** Large, actively engaged participant pool that produces faster completion than most DIY recruitment; Explicit focus on AI training data and human-preference evaluation, not just generic surveys; Transparent pay-per-response model that makes study budgets predictable; Strong data-quality mechanisms and documented evaluation frameworks

**Limitations:** Costs add up quickly at large sample sizes, especially for specialist cohorts; Self-report data still requires careful study design to be scientifically useful; Advanced enterprise and API features are gated behind sales conversations

[Profile (Markdown)](https://openaitools.app/tool/prolific-co.md)

## Scale

Scale positions itself as the infrastructure layer for reliable AI - the data, evaluations and deployment support that sit underneath working systems rather than a single consumer-facing model. Founded in 2016, it built its reputation supplying training data and labelling capacity to the autonomous vehicle and then the generative AI wave, and now describes itself as powering a large share of the world's leading generative AI model builders.

The offering spans three broad areas. Data covers sourcing and expert annotation for training and fine-tuning, including RLHF-style preference data. Evaluation covers public leaderboards and private benchmarks used to measure model capability and safety. Applications covers the build-and-deploy side: identifying a viable use case, constructing the system and owning the outcome, with agentic AI for enterprise operations.

Scale's customer list leans heavily enterprise and public sector, including large technology companies, healthcare providers, media organisations, energy companies and government defence programmes. Because engagements are scoped rather than self-serve, pricing is arranged through a sales process, and the platform is aimed at organisations with serious data volume, strict compliance needs and a mandate to put AI into production.

**Pricing & Plans:** Contact for pricing. Scale does not publish rates; engagements are scoped through a sales conversation and depend on data volume, services and programme complexity.

- **Data Engine:** Human-sourced and expert-annotated training data, including specialist contributors with advanced degrees, at the quality bar frontier labs require.
- **Model evaluation & benchmarks:** Public leaderboards plus private benchmarks that test model capability and safety for the most ambitious AI developers.
- **Enterprise AI applications:** Platform and services teams that pick the right use case, build the system and take ownership of the outcome.
- **Agentic deployment:** Agentic systems designed around measurable business outcomes across private equity portfolios, energy and healthcare operations.
- **Domain expertise:** Programmes spanning healthcare, robotics, defence, public sector and enterprise with human oversight built in.

**Strengths:** Backed by a long track record in training data and model evaluation.; End-to-end coverage from data sourcing through to deployed systems.; Experienced with regulated, classified and safety-critical environments.; Benchmarks and leaderboards give an independent view of model capability.

**Limitations:** No public pricing or self-serve signup - you need a sales conversation to get started.; Enterprise-scale contracting and data operations require real internal commitment.; Overkill for small teams with modest data or evaluation needs.; Some projects involve sensitive government and defence work with strict compliance overhead.

[Profile (Markdown)](https://openaitools.app/tool/scale.md)

## Frequently Asked Questions

### How do Prolific and Scale compare in monthly traffic?

Prolific has 77,755 monthly visits, while Scale has 616,915. Traffic estimates describe audience size, not product quality.

### How do their growth rates compare?

Prolific has a month-over-month growth rate of -24%; Scale has +12.5%.

### How does pricing compare?

Prolific: Paid. Freemium-style access: signing up and building studies is free, and customers pay per completed response at a rate they set (plus a platform fee). AI and enterprise teams can also use the Human Feedback API and managed services, with custom pricing available through sales. Scale: Contact for Pricing. Contact for pricing. Scale does not publish rates; engagements are scoped through a sales conversation and depend on data volume, services and programme complexity.

## Alternatives

| # | Tool Name | Monthly Visits | MoM Growth Rate | Pricing Model | Summary | Profile (Markdown) |
| :--- | :--- | :--- | :--- | :--- | :--- | :--- |
| 1 | [Branded](https://openaitools.app/tool/gobranded-com) | 3,704,728 | +6.6% | Contact for Pricing | Targeted research audiences with AI-verified data quality | [.md](https://openaitools.app/tool/gobranded-com.md) |
| 2 | [Roboflow](https://openaitools.app/tool/roboflow) | 1,431,204 | +6.6% | Freemium, Contact for Pricing | Streamlines computer vision dataset annotation and model training, but is less suited for general LLM text tasks. | [.md](https://openaitools.app/tool/roboflow.md) |
| 3 | [Exa](https://openaitools.app/tool/exa-ai) | 1,062,574 | +16.8% | Freemium, Contact for Pricing | Web search API and crawler built for AI agents | [.md](https://openaitools.app/tool/exa-ai.md) |
| 4 | [Tavily](https://openaitools.app/tool/gpt-researcher) | 989,998 | -0.8% | Contact for Pricing | The real-time web access layer for AI agents and deep research | [.md](https://openaitools.app/tool/gpt-researcher.md) |
| 5 | [Labelbox](https://openaitools.app/tool/labelbox) | 762,803 | -22.8% | Contact for Pricing | Focuses heavily on enterprise data labeling and training data curation, similar to Scale's core annotation business. | [.md](https://openaitools.app/tool/labelbox.md) |
| 6 | [SuperAnnotate](https://openaitools.app/tool/super-annotate) | 386,034 | +37.4% | Free Trial, Contact for Pricing | Provides enterprise multimodal annotation and data management tools, but with less emphasis on managed labeling workforces. | [.md](https://openaitools.app/tool/super-annotate.md) |
| 7 | [Weights & Biases (CoreWeave Forge)](https://openaitools.app/tool/prompts) | 315,624 | -80.2% | Freemium, Contact for Pricing, Free | Track, evaluate, and ship AI models and agents in one connected environment. | [.md](https://openaitools.app/tool/prompts.md) |
| 8 | [Voxpopme](https://openaitools.app/tool/voxpopme-com) | 301,522 | +38.5% | Contact for Pricing | Turn customer voices into confident decisions | [.md](https://openaitools.app/tool/voxpopme-com.md) |
| 9 | [Arize AI](https://openaitools.app/tool/arize-com) | 249,028 | +3.2% | Paid, Contact for Pricing | Focuses on post-deployment LLM observability and evaluation rather than training data generation or annotation. | [.md](https://openaitools.app/tool/arize-com.md) |
| 10 | [Encord](https://openaitools.app/tool/encord-com) | 244,204 | +9.4% | Contact for Pricing | Specializes in data infrastructure and annotation specifically tailored for computer vision and physical AI workloads. | [.md](https://openaitools.app/tool/encord-com.md) |

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Source: https://openaitools.app/compare/prolific-co-vs-scale

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