toolspool

Compare tools

Side-by-side features, use cases and pricing — because the right pick depends on your job and budget, not just the ranking.

Prolific logo
Prolific
✓ verifiedPaid

Research participant marketplace that gives AI teams and academics fast access to verified, screened human data and feedback.

21M visits/mo
Labelbox logo
Labelbox
✓ verifiedFreemium

Data-labeling and RL data platform supplying training data, environments and evaluation for frontier AI labs and enterprises.

1.1M visits/mo
Mercor logo
Mercor
✓ verifiedFree

Marketplace that matches vetted human experts with AI labs to produce training data and model evaluations.

8.9M visits/mo
Appen logo
Appen
✓ verifiedPaid

Long-standing provider of human-labeled, expert-validated training data and model evaluation services for building frontier AI.

1.2M visits/mo
Mathpix logo
Mathpix
✓ verifiedFreemium

OCR and document-conversion tools that turn PDFs, images and handwriting (math, chemistry, tables) into editable text and Markdown.

480K visits/mo
Pricing

No public pricing

No public pricing

No public pricing

No public pricing

No public pricing

Core features
  • 300,000+ verified, screened participants
  • 300+ audience targeting filters
  • Representative and quota-based sampling
  • API and no-code survey tool integrations
  • AI-powered participant quality monitoring (Protocol)
  • Managed services with dedicated project teams
  • Access to vetted domain experts
  • Data labeling across modalities
  • RL environments and reward signals
  • Custom model evaluations and benchmarks
  • Human preference/annotation from an expert network
  • Recursion RL platform for enterprise agents
  • Robotics data (video, trajectories)
  • Curated roles across many expert domains
  • Expert vetting and matching to AI projects
  • Hourly-paid contract work for specialists
  • APEX benchmarks and off-the-shelf datasets
  • Enterprise data partnerships and evaluations
  • Daily payouts to contributors
  • Frontier alignment data (RLHF, SFT, red teaming)
  • Speech and audio data
  • Multimodal / VLM annotation
  • Physical AI data (LiDAR, robotics, sensor fusion)
  • Model integrity, bias and hallucination audits
  • 1M+ vetted contributors, 500+ locales
  • SOC2 and ISO 27001 certified
  • OCR for math, chemistry, tables and handwriting
  • PDF and image to Markdown/text conversion
  • Snip app and Chrome extension
  • Convert and Files APIs for developers
  • Secure Conversion Service for high-volume enterprise use
  • Mathpix Markdown format
Use cases
  • Collecting human preference data for RLHF or model evaluation
  • Running academic behavioral or market research studies
  • Sourcing domain-expert data for specialized AI benchmarks
  • Building training and evaluation datasets
  • Post-training and RLHF for models
  • Benchmarking model capability
  • Training enterprise specialist agents
  • Source expert human data for AI training
  • Run domain-expert model evaluations
  • Find paid remote work as a domain specialist
  • Build custom datasets for AI labs
  • Source training data for AI models
  • Evaluate and benchmark models
  • Annotate multimodal and sensor data
  • Run safety and bias audits
  • Digitizing handwritten math and technical documents
  • Converting PDFs to editable Markdown
  • Making documents accessible and searchable
  • Building OCR into applications
  • Preparing training data for language models
Visit
More in Data Analytics