Phoenix vs Traceloop: Observability, Prompts & Evals Comparison
Compare Phoenix and Traceloop side by side. Both are tools in the Observability, Prompts & Evals category.
The short answer
Choose Phoenix if open-source with active development by Arize.
Choose Traceloop if acquired by ServiceNow for $60-80M providing strong financial backing and integration opportunities.
Quick Comparison
| Category | Observability, Prompts & Evals | Observability, Prompts & Evals |
| Pricing | Open Source | open-source |
| Best For | Engineering teams building agent and RAG systems who want OpenTelemetry-native observability with both self-hosted and managed options | Teams already using Datadog/Splunk wanting LLM observability |
| Website | phoenix.arize.com | traceloop.com |
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Pros & Cons: Phoenix vs Traceloop
- +Open-source with active development by Arize
- +OpenTelemetry-native (no proprietary trace format lock-in)
- +Strong evaluator library out of the box
- +Both self-hosted and managed cloud options available
- +Upgrade path to full Arize enterprise platform
- −Smaller community than Langfuse for open-source-first teams
- −Cloud version's enterprise pricing is contact-sales only
- −UI and feature set tilt toward ML engineers more than application developers
- +Acquired by ServiceNow for $60-80M providing strong financial backing and integration opportunities
- +Built on OpenTelemetry standards with open-source OpenLLMetry SDK
- +Recognized as Gartner Cool Vendor demonstrating industry validation
- +One-line code integration for quick setup and deployment
- +Enterprise-ready with SOC 2, HIPAA compliance and multiple deployment options
- −ServiceNow acquisition may lead to platform changes, pricing adjustments, or strategic shifts
- −Small team of 9 employees may be absorbed into larger ServiceNow organization affecting support
- −Limited transparent pricing information following acquisition
- −Uncertainty around long-term product roadmap under new ownership
When to Choose Phoenix vs Traceloop
- OpenTelemetry-native LLM observability
- Hallucination detection for RAG
- Experiment tracking and golden-set evaluation
About Phoenix
Phoenix is the open-source observability and evaluation platform built by Arize AI for LLM and agent applications. It is OpenTelemetry-native, which means traces written through Phoenix can flow into any OTel-compatible backend in addition to Phoenix's own UI. The platform includes built-in evaluators for hallucination detection, retrieval relevance, and QA correctness, plus dataset management and prompt playground features. Phoenix can be deployed via Docker for self-hosting or used in Arize's managed cloud. The open-source core makes it attractive to teams that want to inspect and customize the observability layer, while the integration with the full Arize platform provides an upgrade path for organizations that need enterprise features like RBAC, SSO, and SLA-backed support.
About Traceloop
Traceloop is an observability and quality assurance platform designed to help teams ship LLM applications 10x faster by transforming evaluation data into continuous feedback loops. The platform enables developers to monitor, test, and improve large language model applications throughout their lifecycle. Built on OpenTelemetry and shipping with OpenLLMetry (their open-source SDK), Traceloop provides real-time monitoring with just one line of code, giving live visibility into prompts, responses, latency, and more. The platform offers built-in quality evaluations for faithfulness, relevance, and safety that automatically apply to production data, along with custom evaluators that users can define and train on annotated examples. Traceloop features automated quality gates that run evaluations automatically on pull requests and in real-time during app execution, plus LLM drift detection to catch performance degradation before it reaches users. The platform supports 20+ LLM providers including OpenAI, Anthropic, Gemini, Bedrock, and Ollama, and integrates with popular frameworks like LangChain, LlamaIndex, and CrewAI. In March 2026, Traceloop was acquired by ServiceNow for $60-80 million, marking the third Israeli acquisition by ServiceNow in under three months. The platform is SOC 2 and HIPAA compliant with cloud, on-premises, and air-gapped deployment options. Traceloop has been recognized as a Gartner Cool Vendor and serves notable clients including HiBob, Target, Miro, IBM, and Babbel.
What is Observability, Prompts & Evals?
Tools for monitoring LLM applications in production, managing and versioning prompts, and evaluating model outputs. Includes tracing, logging, cost tracking, prompt engineering platforms, automated evaluation frameworks, and human annotation workflows.
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