Data Labeling Outsourcing Marketplace
Post a data labeling or data annotation RFP, then compare standardized proposals when relevant providers respond, all in one inbox.
Stop Sourcing Vendors Manually
Post one RFP for data labeling or data annotation and receive standardized proposals when relevant vendors respond. OpenTrain runs the marketplace; vendors deliver the labels.
Provider Consideration
Put one data labeling brief in front of relevant providers.
Describe your project once: scope, tools, languages, and team needs. The marketplace routes your data labeling outsourcing brief for consideration by relevant vendors and BPO partners. OpenTrain runs the marketplace; vendors deliver the labels.
Standardized Proposals
Compare data annotation outsourcing proposals side-by-side.
When providers respond, proposals use a consistent format: pricing model, team size, delivery timeline, tool expertise, and client references. The marketplace standardizes data annotation outsourcing quotes so you can shortlist in one inbox instead of chasing scattered emails or inconsistent formats.
Provider Profiles
Review provider details before you choose who to contact.
Browse provider profiles, compare proposal details, and message providers from one workflow before deciding who should run the work.
Direct Terms
Choose the commercial terms that fit the engagement.
OpenTrain helps with sourcing and proposals. The selected vendor runs delivery in the agreed tools, with payment terms handled according to the engagement.
Provider Profiles Across Major Annotation Platforms
Provider Profiles
Proposal Workspace
Annotation Platforms
How Data Labeling Outsourcing Works on OpenTrain.
Outsource your data labeling or data annotation through one RFP and compare responses from relevant vendors. OpenTrain runs the marketplace; the vendor you pick delivers the labels.
Step 01
Post Your RFP
Describe your project once: scope, annotation tools, languages, team size, and timeline. Your RFP is ready for relevant providers to consider.
- Structured RFP form: specify domains, tools, languages, and capacity needs
- Enough detail for providers to evaluate fit before responding
- No required sales call to post your brief.
Step 02
Relevant Vendors Review the Brief
OpenTrain routes your RFP for consideration by data labeling and LLM service providers that may fit your project requirements.
- Context by domain expertise, annotation tooling, language coverage, and capacity
- Profiles can show services, tools, and work examples
- Compare providers before deciding who to move forward with
Step 03
Compare Proposals Side-by-Side
When providers respond, they use the same standardized proposal format: pricing model, team size, delivery timeline, tool expertise, and client references. Compare in one inbox instead of chasing scattered emails.
- Standardized proposals with pricing, capacity, timelines, and references
- Message vendors directly to ask questions — all in one place
- Side-by-side comparison so you can build a shortlist
Step 04
Select Your Vendor and Start Working
Choose your vendor and begin the engagement on agreed terms. The selected vendor delivers the work in the tools you agree to use.
- Set commercial terms with the selected vendor
- Work happens in the tools you agree to use
- No exclusivity. Work with multiple vendors simultaneously if you need to.
Find Your Next Data Labeling Partner
Post one RFP and compare standardized proposals from data labeling and LLM service providers when they respond. Compare pricing, capacity, and references in one inbox.
Describe Your Project Once, Compare Provider Proposals
Outsource data labeling or data annotation in one RFP. The marketplace routes your brief for consideration by relevant vendors and BPO partners who can respond with standardized proposals. OpenTrain runs the sourcing layer; the vendor you pick delivers the labels.
One Inbox for Every Proposal
- Data labeling vendor profiles
- Standardized proposals in one inbox
- Provider messaging and comparison
- No platform migration required
Outsource Any AI Data Program Through the Marketplace
Post an RFP for any project type below. The marketplace covers major AI data workstreams, from RLHF and evaluation to image, video, and document annotation, and routes your outsourcing brief for provider consideration.
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
Find providers for RLHF, evaluation, preference data, red teaming, and code QA.
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
Source vendors for image, video, LiDAR, document, text, and audio annotation at scale across any domain.
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 Beyond core data labeling services the marketplace can outsource specialty programs as well — including RLHF services and LLM evaluation services. If you want OpenTrain to run the whole outsourcing program on top of the marketplace, our managed service can help with vendor selection, QA, and program management while vendors and freelancers still deliver the labels.
Data Labeling Outsourcing Marketplace FAQ
Common questions about outsourcing data labeling and data annotation through OpenTrain.