DriftRail vs Langfuse vs Helicone: Which LLM Observability Platform is Right for You?

The LLM observability market has exploded in 2025-2026. If you're evaluating platforms to monitor your AI applications, you've likely encountered Langfuse, Helicone, and DriftRail. While all three help you understand what your LLMs are doing, they serve different needs.

This guide breaks down the key differences to help you choose the right tool for your use case.

Quick Comparison

When to Choose Each Platform

Choose DriftRail if...

• Compliance is non-negotiable. You need SOC2, HIPAA, or GDPR audit reports that you can hand to auditors. DriftRail generates these with one click.
• You're in a regulated industry. Healthcare, finance, legal, and insurance companies need more than logging — they need immutable audit trails, PII redaction, and DSAR handling.
• You need to block dangerous outputs. DriftRail's guardrails can block, redact, or warn on high-risk content before it reaches users.
• You want AI-powered risk classification. 8 built-in detectors (hallucination, toxicity, PII, prompt injection, etc.) plus the ability to write custom detection prompts.
• Brand safety matters. Block competitor mentions, flag negative sentiment, and enforce tone requirements.

Choose Langfuse if...

• You're building with LangChain. Langfuse has the deepest LangChain integration with native tracing.
• You want to self-host. Langfuse is fully open-source (MIT) and can run on your own infrastructure.
• You need a prompt playground. Iterate on prompts directly in the UI with version control.
• You're focused on evaluation. Langfuse's evaluation framework lets you score outputs and track quality over time.
• Budget is tight. The open-source option means you can run it for free on your own servers.

Choose Helicone if...

• Cost optimization is your priority. Helicone has the most advanced cost tracking and caching features.
• You need response caching. Cache identical requests to reduce API costs and latency.
• You want lightweight integration. Helicone works as a proxy — just change your base URL.
• You're optimizing for latency. Detailed latency breakdowns help identify bottlenecks.

The Compliance Gap

Here's the uncomfortable truth: most LLM observability tools were built for developers, not compliance teams.

Langfuse and Helicone are excellent for understanding what your LLMs are doing. But when an auditor asks "How do you ensure your AI doesn't expose PII?" or "Can you prove your AI outputs are being monitored for hallucinations?", you need more than logs.

DriftRail was built for this scenario. Every event is stored in immutable, append-only tables with database triggers that prevent tampering. Compliance reports map your data to specific SOC2, HIPAA, and GDPR controls. PII is automatically detected and can be redacted before storage.

Custom Detections: DriftRail's Secret Weapon

One feature that sets DriftRail apart is custom detection prompts. While we provide 8 built-in detectors, you can write your own:

{
  "id": "medical_advice",
  "name": "Medical Advice Detection",
  "prompt": "Analyze the AI output for medical advice. Flag if the response includes diagnosis, treatment recommendations, or medication suggestions without appropriate disclaimers. Return risk level and specific concerns."
}

This lets you build industry-specific classifiers without training custom models. The detection runs on every event and results are stored alongside your standard classifications.

Pricing Comparison

Note: DriftRail's pricing includes AI-powered classification on every event. Langfuse and Helicone are primarily logging/tracing tools — you'd need to add your own classification layer.

Bottom Line

If you're a startup iterating fast and need lightweight observability with great LangChain support, Langfuse is hard to beat — especially with the self-hosted option.

If you're optimizing costs and want caching plus detailed cost analytics, Helicone is purpose-built for that.

If you're in a regulated industry or need to prove AI governance to auditors, customers, or your board, DriftRail is the only platform with built-in compliance reports, inline guardrails, and immutable audit trails.

The best choice depends on your priorities. Many teams actually use multiple tools — Langfuse for development tracing, DriftRail for production compliance. They solve different problems.