The #1 Talent Network for AI Training & Data Labeling
Hire pre-vetted domain experts at scale for LLM evaluation, RLHF, red teaming, data labeling, and more. Post a job, get a curated shortlist, and bring talent into any platform you use.
Freelance AI Trainer / Data Labeler?
Join 124,000+ freelancers
One Platform to Source, Manage, and Pay AI Training Talent
Source vetted talent, manage projects, and handle payments in one workspace. Keep your preferred tools and workflows.
Talent Matching
Post your requirements. Review only qualified matches.
Post once and receive a shortlist of domain experts matched to your project. Our AI screens resumes, runs skills tests, and conducts live interviews so you never wade through unqualified applications.
Any Platform
Bring vetted talent into any tool you use.
Deploy experts into any third-party platform, any open-source tool, or your own custom annotation environment. No vendor lock-in, no platform migration.
Built-In Workspace
Chat, docs, and project management. All built in.
Centralize team communication, share instructions, assign training modules, and track progress. No need for separate tools.
Global Payments
Pay talent directly. Flat fee. No hidden markups.
Pay securely across 180+ countries. You see exactly what talent earns and what the platform fee is. No bundled software charges, no surprise costs.
Hire Top Talent for Any AI Training Need. Any Domain, Any Scale.
From RLHF and red teaming to image annotation and multilingual evaluation. Pre-vetted domain experts and skilled annotators ready to work inside your tools.
Post-Training & Alignment
RLHF preference ranking, DPO pair generation, and reward model training data. Our experts evaluate and rank model outputs so your models learn what good looks like.
Reasoning & Verification
Expert evaluation of chain-of-thought reasoning, process reward annotation, and verification of math, code, and logic outputs.
Red Teaming & Safety
Adversarial prompt crafting, jailbreak discovery, bias evaluation, and safety alignment testing.
Domain Expert Annotation
PhDs and professionals in mathematics, medicine, law, finance, and engineering providing expert-grade training data.
Evaluation & Benchmarking
Human evaluation of model outputs, benchmark creation, A/B preference testing, and ongoing quality monitoring.
Multimodal & Multilingual
Vision, audio, video, and document annotation with cross-modal alignment across 118+ languages.
LLM & Agents
Hire vetted domain experts to train and evaluate your LLMs, driving higher quality and more reliable model behavior.
LLM Evaluation 
Red Teaming 
Hallucination Audits 
RLHF & Preference Data 
Supervised Fine-Tuning 
Code Generation Review 
Function Calling 
Computer Use Agent Training 
Reasoning Step Verification 
Multilingual AI Training 
Reasoning Problem Creation 
Agent Simulations 
RL Environment Design Data Labeling
Hire experienced annotators to deliver precise, consistent labels at scale across vision, text, audio, and 3D.
Document Annotation 
Image Annotation 
Segmentation 
Video Annotation 
Text Annotation 
Speech and Audio Labeling 
Time Series Annotation 
Point Cloud Annotation 
Medical Imaging Annotation 
Satellite Imagery Annotation Better Talent. Better Data. Better AI.
Get started with self-service hiring or let our team handle it end-to-end.
Post a Job, Hire Experts into Any Platform
Describe your requirements and receive a curated shortlist of domain experts matched to your project. 15% flat fee, no hidden markups.
Full-Service, End-to-End
- Recruiting & live vetting
- Onboarding & training
- Daily management & QA
- Dedicated program lead
Build a career training the world's top AI models.
Freelance AI Trainer?
Join 124,000+ freelancers
Data Labeling Company?
Find clients and recruit talent
Works With Every Annotation Platform
From Job Post to Deployed AI Training Team
Post your RLHF, evaluation, or annotation project. Get a pre-screened shortlist of domain experts. Deploy them directly into your annotation tools.
Post Your Job to 124,000+ Experts
Define your requirements and go live in minutes. Your job reaches our global network of pre-vetted AI Trainers and Data Labelers. No sales calls, no contracts, no minimums.
- Guided job form: specify domains, languages, seniority, and tools
- Published pricing: 15% flat fee, visible before you post
- Reaches specialists across 180+ countries and 100+ languages
Mandarin
SpanishEvery Candidate Screened, Tested, and Scored
Our matching system draws on performance data from across 20+ AI training platforms. Every applicant goes through AI interviews and skill testing before they reach your shortlist. Candidates matched on proven ability, not self-reported skills.
- Unified work history: real ratings and performance data from 20+ AI training platforms
- AI interviews that test domain knowledge and reasoning before candidates reach you
- Domain-specific skill assessments calibrated to your project requirements
Hire & Deploy Into Any Platform You Use
Hire from your vetted shortlist and add experts directly into whatever annotation tools your team already uses. No migrations, no vendor lock-in. You keep full control of your stack and your data.
- Works with Label Studio, CVAT, Argilla, doccano, or any annotation tool your team uses
- Send offers and onboard hires without switching platforms or migrating data
- Your data stays in your tools. OpenTrain never hosts or touches training datasets.
Manage Work and Pay Your Team Directly
Keep your entire project in one place. Update guidelines, coordinate with your team, and handle payments without juggling external tools. Set your own rates and pay talent directly through OpenTrain.
- Edit and publish instructions that reach your entire team instantly
- Chat, training modules, and progress tracking in one workspace
- Pay per hour, per task, or fixed price. 15% flat fee, no hidden costs.
Everything You Need to Know
Common questions about working with OpenTrain.