Braintrust wins for teams shipping production LLM applications. CI/CD-native evals, automatic tracing, collaborative experiments, and self-hosting options make it the most complete platform.
Runner-up alternatives:
Choose Braintrust if automated evaluation in CI/CD and production observability matters. Pick others if you only need basic logging or have specific constraints (e.g., open-source, LangChain-only, etc.).
Arize AI started as an ML model monitoring platform focused on traditional machine learning operations. The company built features for drift detection, model performance tracking, and tabular data monitoring, but these are tools designed for predictive ML models deployed years ago.
As LLM applications moved from prototypes to production, Arize expanded into generative AI through its Arize Phoenix open-source framework and later added LLM capabilities to its web application. Arize now offers LLM evaluation, prompt versioning through their Prompt Hub, and tracing for conversational applications.
However, teams building production LLM applications encounter specific workflow gaps:
Teams shipping LLM applications need platforms that integrate evaluation, experimentation, and observability into a single system, not separate tools bolted onto ML monitoring infrastructure.

Braintrust takes an evaluation-first approach to LLM development. Automated evals run in CI/CD pipelines and block deployments when quality drops, catching regressions before users see them. Unlike LLM observability tools that surface issues after release, Braintrust prevents bad prompts from shipping with proactive measurements.
Braintrust consolidates experimentation, evaluation, and observability into a single system. Teams use Braintrust instead of juggling multiple tools. Traces, evals, and decisions stay in one place, with engineers and product managers reviewing outputs together and choosing what ships.
Pros
Evaluation framework
Automatic tracing and logging
Prompt and dataset management
CI/CD native integration
Deployment flexibility
Cons
Best for
Companies building production LLM apps that care about accuracy, quality, and safe releases.
Pricing
Free tier includes 1M trace spans per month, unlimited users, and 10,000 evaluation runs. Sufficient for most early-stage teams and small production applications. Pro plan starts at $249/month, with custom enterprise plans available. See pricing details →
| Feature | Braintrust | Arize | Winner |
|---|---|---|---|
| LLM evaluation framework | ✅ Eval-first platform that gates releases | ✅ Observability-first platform with evals | Braintrust |
| Prompt versioning | ✅ Full version control with A/B testing | ✅ Has Prompt Hub with versioning | Braintrust |
| Trace visualization | ✅ Built for nested agent calls and RAG | ✅ Built on an ML monitoring foundation | Braintrust |
| Dataset management | ✅ Integrated with eval workflow and versioning | ❌ Available but separate workflow from tracing | Braintrust |
| Pre-production testing | ✅ Comprehensive experiment comparison | ❌ Limited experiment framework available | Braintrust |
| Deployment model | ✅ Cloud and on-prem or self-hosted | ✅ Cloud and on-prem or self-hosted | Tie |
| CI/CD integration | ✅ Native GitHub/GitLab integration with deployment blocking | GitHub Actions integration for experiments, no automatic deployment blocking | Braintrust |
| Free tier | ✅ 1M trace spans per month with unlimited users | ✅ 25K spans per month for a single user only | Braintrust |
Braintrust's combined observability and evaluation framework catches regressions before they hit production. Start with Braintrust's free tier →

Langfuse offers an open-source observability platform offering trace logging, prompt management, and basic analytics in addition to cloud software. The open source and self-hosting option may appeal to teams with strict data policies, but you maintain infrastructure yourself.
Pros
Cons
Pricing
Free for open-source self-hosting. Paid plan starts at $29/month. Custom enterprise pricing.
Best for
Teams requiring open-source self-hosted deployment with full data control who have DevOps resources to build custom evaluation pipelines from scratch.
Read our guide on Langfuse vs. Braintrust.

Fiddler AI is an observability platform that extends from traditional ML monitoring into LLM observability. The platform offers monitoring, explainability, and safety features for both classical ML models and generative AI applications.
Pros
Cons
Pricing
Custom enterprise pricing only.
Best for
Organizations already using Fiddler for traditional ML monitoring who want unified observability across both classical and generative AI models.

LangSmith is the observability platform built by the LangChain team. It traces LangChain applications automatically and provides evaluation tools designed specifically for LangChain workflows.
Pros
Cons
Pricing
Free tier with 5K traces monthly for one user. Paid plan at $39/user/month. Custom enterprise pricing with self-hosting.
Best for
Teams running their entire LLM stack on LangChain or LangGraph who prioritize zero-config framework integration over flexibility and accept per-trace pricing that scales with usage volume.
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Helicone acts as an LLM proxy between your app and LLM providers. It logs requests and responses, but stops at observability. No evals, datasets, or experimentation.
Pros
Cons
Pricing
Free tier (10,000 requests/month). Paid plan at $79/month.
Best for
Teams using only OpenAI models who need basic proxy logging and cost tracking without evaluation capabilities or multi-provider support.
| Feature | Braintrust | Langfuse | Fiddler AI | LangSmith | Helicone |
|---|---|---|---|---|---|
| Distributed tracing | ✅ | ✅ | ✅ | ✅ | ✅ |
| Evaluation framework | ✅ Native | ✅ Experiments, LLM-as-Judge | ✅ | ✅ | ❌ |
| CI/CD integration | ✅ | ✅ Documented guides | ❌ | Partial | ❌ |
| Deployment blocking | ✅ | ❌ | ❌ | ❌ | ❌ |
| Prompt versioning | ✅ | ✅ | ❌ | ✅ | ❌ |
| Dataset management | ✅ | ✅ | ✅ | ✅ | ❌ |
| Self-hosting | ✅ | ✅ | ✅ | ✅ | ❌ |
| Proxy mode | ✅ | ❌ | ❌ | ❌ | ✅ |
| Multi-provider support | ✅ | ✅ | ✅ | ✅ | ❌ OpenAI only |
| Experiment comparison | ✅ | ✅ | ✅ | ✅ | ❌ |
| Custom scorers | ✅ | ✅ | ✅ | ✅ | ❌ |
| A/B testing | ✅ | ❌ | ❌ | Partial | ❌ |
| Cost tracking | ✅ | ✅ | ✅ | ✅ | ✅ |
| ML model monitoring | ❌ | ❌ | ✅ | ❌ | ❌ |
| Free tier | 1M spans, 10K evals | 50K spans | None | 5K traces | 10K requests |
Choose Braintrust if: You need CI/CD deployment blocking, end-to-end evaluation workflows, cross-functional collaboration, or complex multi-agent tracing.
Choose Langfuse if: Open-source self-hosting is mandatory and you have resources to build custom eval pipelines.
Choose Fiddler AI if: You already use Fiddler for ML monitoring and need unified observability across traditional and generative AI models.
Choose LangSmith if: Your entire stack runs on LangChain/LangGraph and deep framework integration outweighs flexibility concerns.
Choose Helicone if: You only use OpenAI and need basic proxy logging without evaluation capabilities.
Braintrust covers the entire LLM development lifecycle, including prompt experimentation, automated CI/CD evaluation, statistical comparison, deployment blocking, and production observability. The free tier includes 1M trace spans and 10K eval runs to catch regressions before customers see them.
Companies like Notion, Zapier, Stripe, and Vercel use Braintrust in production. Notion reported going from fixing 3 issues per day to 30 after adopting the platform.
Get started free or schedule a demo to see how Braintrust handles evaluation and observability for production LLM applications.
Braintrust offers the most complete Arize alternative with CI/CD-native evaluation, automatic deployment blocking, and integrated observability. Unlike Arize's ML-first architecture, where LLM features were added later, Braintrust was built specifically for generative AI workflows from day one. The platform combines prompt experimentation, automated testing, and production tracing in one system, eliminating the need to stitch together multiple tools.
Arize Phoenix offers a free tier with 25K trace spans per month for one user. However, Braintrust provides a more generous free tier with 1M trace spans and 10K evaluation runs monthly for unlimited users. Braintrust's free tier also includes CI/CD integration and deployment blocking features that Arize doesn't offer, even in paid plans.
Not with modern platforms. Braintrust consolidates tracing, evaluation, prompt management, and dataset versioning in one system. Evaluation results automatically link to specific traces and datasets.
Braintrust, Langfuse, LangSmith, and Fiddler AI support multiple providers, including OpenAI, Anthropic, Cohere, and Azure OpenAI. Helicone only supports OpenAI. Braintrust's proxy mode works with all major providers without code changes, while framework-specific tools like LangSmith require additional instrumentation for non-LangChain stacks.
Braintrust offers 40x more free trace spans (1M vs 25K), unlimited users instead of 1, and evaluation features that Phoenix lacks. Braintrust provides CI/CD deployment blocking, prompt versioning with A/B testing, and integrated dataset management. Phoenix focuses on basic tracing without evaluation automation.