Neptune.ai
Experiment tracker for foundation-model training, debugging, and training observability; acquisition by OpenAI announced.
Neptune helps AI teams track experiments, monitor training, debug model behavior, and understand complex foundation-model training runs as they happen.
Positioning
Experiment tracker for foundation-model training
Key facts
- HQ location
- Warsaw, Poland / remote
- Founded
- 2017
- Employee range
- 51-200 (51-200 pre-acquisition)
- Funding stage
- Bootstrapped
- Company type
- Unknown (Acquired / OpenAI announced)
- Pricing model
- Subscription (SaaS subscription; hosted service winding down post-acquisition)
- Last updated
- Jun 21, 2026
Revenue estimate
Unknown
Valuation estimate
Deal terms undisclosed; Reuters reported under $400M stock value estimate
Investments
Acquisition by OpenAI announced Dec 2025; prior public funding was modest/undisclosed in detail
Target customers
AI labs, ML researchers, and teams training large/foundation models
Key competitors
Weights & Biases, Comet, MLflow, WhyLabs, TensorBoard
Known customers
OpenAI, Samsung, Roche, HP and foundation-model teams publicly referenced
Classification (raw research text)
- Core focus
- Foundation-model experiment tracking
- Core industry
- AI Development Tools / MLOps
- Core category
- Experiment tracking and training observability
Shown verbatim from the research spreadsheet — deriving structured segment/industry tags from this text is a future phase.
Attribute breakdown
- AI Workflows Secondary feature
- AI Fine-tuning / Custom Model Training Secondary feature
- System / API Integration Secondary feature
- Traditional Machine Learning Primary focus
- AI Quality Assurance / LLM Evaluation Secondary feature
- AI Observability / Monitoring Primary focus
- AI Asset Inventory / Model Registry Secondary feature
- Analytics / BI / Decision Intelligence Secondary feature
Show all 32 attributes
- AI Workflows Secondary feature
- AI Automation / Business Process Automation Not emphasized
- AI Fine-tuning / Custom Model Training Secondary feature
- Agent Builder / Agent Configuration Not emphasized
- Multi-agent Orchestration / Runtime Not emphasized
- System / API Integration Secondary feature
- Prompt Management / Prompt Engineering Not emphasized
- Retrieval-Augmented Generation Not emphasized
- Graph RAG / Knowledge Graph Retrieval Not emphasized
- Enterprise Search / Knowledge Management Not emphasized
- AI / LLM Data Pipeline Not emphasized
- Document AI / Document Processing Not emphasized
- Model Deployment / Inference Infrastructure Not emphasized
- Traditional Machine Learning Primary focus
- AI Quality Assurance / LLM Evaluation Secondary feature
- AI Observability / Monitoring Primary focus
- AI Security / Guardrails Not emphasized
- Data Privacy / PII / Confidential AI Not emphasized
- AI Governance / Policy Management Not emphasized
- AI Risk / Compliance Not emphasized
- AI Asset Inventory / Model Registry Secondary feature
- Human-in-the-Loop Review / Feedback Not emphasized
- Call Transcription / Speech-to-Text Data Capture Not emphasized
- Conversation Intelligence / Speech Analytics Not emphasized
- Text Chatbots / Conversational Assistants Not emphasized
- Voice AI Agents Not emphasized
- Voice Infrastructure / STT / TTS Not emphasized
- AI for Customer Experience / Support Automation Not emphasized
- Sales / Revenue Intelligence Not emphasized
- Analytics / BI / Decision Intelligence Secondary feature
- Enterprise App / Internal Tool Builder Not emphasized
- Vertical-Specific AI Not emphasized