8 Best OpenAI Evals Alternatives in 2026 (Open Source)
OpenAI Evals — Evals is a framework for evaluating LLMs and LLM systems, and an open-source registry of benchmarks.
Short answer
- Closest match to OpenAI Evals: DeepEval.
- Most actively developed: Agenta (8,893 commits in the last 90 days).
- Fastest growing: Langfuse (+1,812 GitHub stars in the last 30 days).
- No commit in 6+ months: Ragas and UpTrain.
These 8 open-source tools do the same job. They are ordered by how closely they match OpenAI Evals, with live GitHub data so you can see which projects are actively maintained.
| Tool | GitHub stars | Stars / 30d | Last commit |
|---|---|---|---|
| OpenAI Evals(original) | 19.5k | +230 | 2026-04-14 |
| DeepEval | 18.6k | +676 | 2026-10-01 |
| Ragas | 15.9k | +441 | 2026-02-24 |
| Promptfoo | 25.6k | +1,112 | 2026-10-02 |
| Langfuse | 35.3k | +1,812 | 2026-10-02 |
| phoenix | 11.7k | +416 | 2026-10-02 |
| langwatch | 4.9k | +275 | 2026-10-02 |
| Agenta | 4.8k | +130 | 2026-10-02 |
| UpTrain | 2.4k | +4 | 2024-07-29 |
1. DeepEval
The LLM Evaluation Framework
What sets it apart: Most comprehensive open-source LLM eval framework with 30+ research-backed metrics including agentic, RAG, multi-turn, MCP, and multimodal — vs Ragas (RAG-only) or custom eval scripts
Best for: Teams needing comprehensive LLM/agent evaluation pipelines; CI/CD integration for LLM app quality gates; RAG pipeline evaluation and optimization
2. Ragas
Supercharge Your LLM Application Evaluations 🚀
What sets it apart: vs manual LLM evaluation: Purpose-built evaluation framework with both LLM-based and traditional metrics, automated test generation, and seamless integration with popular LLM frameworks
Best for: Evaluating RAG pipeline quality with automated metrics; Generating comprehensive test datasets for LLM apps; Building continuous evaluation feedback loops
3. Promptfoo
Open-source CLI and library for evaluating and red-teaming prompts, agents, RAG systems, and LLM apps
What sets it apart: Unlike LangSmith (production observability) or Langfuse (logging), promptfoo is the only open-source tool combining eval + red teaming + CI/CD code scanning — now backed by OpenAI while remaining fully MIT-licensed
Best for: Teams hardening LLM apps against prompt injection and jailbreaks with automated red teaming; Engineering teams adding LLM eval regression tests to CI/CD pipelines
4. Langfuse
Open-source LLM engineering platform for observability, evaluation, prompt and dataset management
What sets it apart: Unlike LangSmith (LangChain-specific) or Helicone (proxy-based), Langfuse is fully open-source, framework-agnostic, and self-hostable, combining tracing, prompt management, evaluations, and datasets in a single platform built on ClickHouse for scalable production use.
Best for: Teams operating production LLM applications who need tracing, prompt management, and evaluation in one platform; Organizations requiring self-hosted LLM observability for data privacy compliance
5. phoenix
AI Observability & Evaluation
What sets it apart: Full-stack AI observability (tracing + eval + datasets + prompt management) in one open-source platform — vs LangSmith which is closed-source and LangChain-specific
Best for: Debugging and monitoring LLM applications in production; Systematic prompt engineering and experiment tracking
6. langwatch
The platform for LLM evaluations and AI agent testing
What sets it apart: Unified platform combining agent simulation, evaluation, observability, and prompt optimization with OpenTelemetry-native design — vs separate tools for tracing (Langfuse), eval (DeepEval), and prompt management
Best for: Teams wanting eval + observability + prompt management in one tool; Agent simulation testing before production deployment; Organizations needing OpenTelemetry-native LLM observability
7. Agenta
The open-source LLMOps platform: prompt playground, prompt management, LLM evaluation, and LLM observability all in one place.
What sets it apart: Unified open-source LLMOps platform combining prompt playground, version control, 20+ evaluators, and OTel-native observability in one tool — vs separate tools for each
Best for: Teams needing integrated prompt management + evaluation + observability; Product teams collaborating with SMEs on prompt engineering; Organizations wanting open-source LLMOps alternative
8. UpTrain
Open-source platform to evaluate and improve generative AI applications with 20+ preconfigured evaluations
What sets it apart: vs generic eval tools: 20+ preconfigured evaluations with customizable prompts, few-shot examples, and scenario descriptions — all running locally for data privacy with root cause analysis on failures
Best for: RAG system evaluation and quality assurance; LLM application testing before production deployment; Safety and security testing for prompt injection vulnerabilities
FAQ
- What are the best alternatives to OpenAI Evals?
- The closest open-source alternatives to OpenAI Evals are DeepEval, Ragas and Promptfoo, followed by Langfuse, phoenix and langwatch. They are ranked by how closely they match what OpenAI Evals does.
- Which OpenAI Evals alternative is the most popular?
- Langfuse has the most GitHub stars among OpenAI Evals alternatives, with 35,301 stars.
- Which OpenAI Evals alternative is the most actively maintained?
- By recent activity, Agenta (8,893 commits in the last 90 days) is the most actively developed alternative.