Skip to main content
Introducing Respan Router

Promptfoo vs Traceloop (2026)

Updated March 10, 2026

vs

Overview

Rating
10.0 / 10
Rating
10.0 / 10
Best For
—
Best For
Teams already using Datadog/Splunk wanting LLM observability
Product Summary

Promptfoo is an open-source tool for testing and evaluating LLM prompts. It lets developers define test cases, run them against multiple models, compare outputs side-by-side, and catch regressions before deployment. Supports custom scoring functions, red-teaming, and CI/CD integration for automated prompt testing.

Product Summary

The OpenTelemetry standard for AI. Pipes LLM telemetry into Datadog, Splunk, or any OTel backend.

Starting Price
$0Per perpetual
Starting Price
open-source
Free Trial
Yes
Free Trial
No
Free Version
No
Free Version
No

Key features

Core capabilities each platform advertises.

PromptfooPromptfoo
Data not available
TraceloopTraceloop
  • OpenTelemetry
  • OpenLLMetry
  • Vendor-neutral
  • OTel integration

Strengths and tradeoffs

What each tool does well, and the limitations to keep in mind.

PromptfooPromptfoo

Pros

  • Completely free and open source (MIT license)
  • Fast with quality features like live reloads and caching
  • Built-in red teaming and security vulnerability scanning
  • Trusted by large companies with strong community

Cons

  • CLI-focused creates friction for non-technical users
  • Limited observability for complex production agents
  • No version control for prompts, data, or metrics
  • Offline nature hits ceiling for production scale
TraceloopTraceloop

Pros

  • 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

Cons

  • 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

Compare Promptfoo and Traceloop on your own traffic

10KFree traces/mo
1,000+Models
5 minSetup

Respan lets you trace LLM and agent calls across any model or framework, A/B test prompts on production traffic, and route requests across 1,000+ models through one gateway.

Try Respan free

Other popular comparisons