Humanloop
Prompt management and LLM evaluation platform — acqui-hired by Anthropic; platform ceased September 2025.
Humanloop is profiled here as a Prompt Management tool for engineering teams. Read about features, pricing, and how it compares to related options in the tools directory.
Description
Short Intro: Humanloop was a proprietary LLM evaluation and prompt management platform built by Humanloop, Inc., a UCL spinout co-founded in 2020 by Raza Habib (ML PhD, UCL), Peter Hayes (ML PhD, UCL), Jordan Burgess (ex-Amazon Alexa), and UCL Professors Emine Yilmaz and David Barber. Anthropic acqui-hired the founding team in August 2025, confirmed by an Anthropic spokesperson to TechCrunch. Anthropic did not acquire the platform's assets or intellectual property. Humanloop's platform shut down September 8, 2025. Teams migrating from Humanloop have moved to Braintrust, Vellum, Langfuse, and Agenta.
Key Capabilities (historical):
Prompt versioning and management with rollback across team members and production environments
LLM evaluation framework with structured test cases, expected outputs, and quality metrics across versions
Production observability logging LLM inputs, outputs, and user feedback
Model comparison across providers on the same prompt dataset
A/B testing for prompt variants against live production traffic
Human feedback collection and labeling workflows for evaluation and fine-tuning
Team collaboration for engineers, product managers, and domain experts on shared prompt and evaluation workflows
Alternative tools
- Google AI Studio
Free browser workspace for prototyping with Gemini models
- Basalt
Collaborative prompt management and deployment for AI teams
- Promptmetheus
Prompt engineering IDE for composing and testing LLM prompts
- BAML
A domain-specific language for typed LLM functions
- Langtail
Collaborative prompt playground with testing and deployment
- Lunary
Open-source prompt management and observability for LLM apps