Free and open first
Best Llm Developer Tools in 2026
- 26 apps
- Research read 7 Oct 2026
- How the order is worked out
- 1
DeepEval
Free plan Open source APILinuxMac+3DeepEval offers a broad toolkit for evaluating AI systems across modalities, metrics, and agent workflows.
- 2
Langfuse
Free plan Open source APILinuxSelf-hosted+1Langfuse brings tracing, prompt workflows, and evaluation features into one AI engineering platform, with both hosted and self-hosted options.
- 3
Opik
Free plan Open source APILinuxMac+3Opik brings tracing, evaluation, testing, and production monitoring into one platform, with both cloud and self-hosted options.
- 4
Promptfoo
Free plan Open source APILinuxMac+3Promptfoo combines prompt evaluation with red-team testing and a broad provider and integration list.
- 5
Arize Phoenix
Free plan APISelf-hostedWebPhoenix brings tracing, evaluation, prompt inspection, and dataset experiments to AI application teams. It is free and open source, with deployment choices and usage management left to users.
- 6
Braintrust
Free plan APISelf-hostedWebBraintrust combines production trace inspection with dataset evaluations and prompt iteration.
- 7
CrewAI AMP
Free plan APISelf-hostedWebChoose CrewAI AMP if your team needs several ways to build multi-agent workflows alongside tracing and governance controls.
- 8
Helicone
Free plan APISelf-hostedWebHelicone brings routing and observability tools together, with a free tier and self-hosting options. Its maintenance-mode status is worth weighing when considering it for a new deployment.
- 9
LangSmith
Free plan APILinuxMac+3LangSmith combines agent evaluation with prompt tools and observability, including cost and trajectory tracking.
- 10
LlamaIndex
Free plan APILinuxSelf-hosted+1LlamaIndex combines document parsing, extraction, classification, and retrieval pipelines for teams building document-centered AI workflows.
- 11
Haystack
Free plan APISelf-hostedHaystack provides a free framework for assembling AI systems from modular pipelines, with integrations and self-hosted deployment options.
- 12
LangChain
Free plan APISelf-hostedChoose LangChain to build agents around models and tools using its configurable harness, middleware, and wide range of integrations.
- 13
LiteLLM
Free plan APISelf-hostedWebChoose LiteLLM if your platform team needs a shared gateway for many providers, with routing and spend controls.
- 14
DSPy
Free plan APISelf-hostedChoose DSPy if you are building AI programs in Python and want task signatures, composable modules, and prompt optimization.
- 15
Portkey
Free plan APISelf-hostedWebPortkey brings model access, prompt management, and activity monitoring under one platform. Review the plan's log retention, deployment, and support terms against your team's requirements.
- 16
OpenRouter
Free plan APIWebOpenRouter brings model access, routing and integrations together behind a single endpoint. The Free plan has a daily request cap, while pay-as-you-go plans apply platform fees to credit purchases.
- 17
PromptLayer
Free plan APISelf-hostedWebPromptLayer brings prompt editing, evaluation, and operational monitoring into one workflow, with collaboration features for technical and non-technical contributors.
- 18
Replicate
Free plan APIWeb6.6 Visit site - 19
Ragas
Free plan APILinuxSelf-hostedRagas offers a broad evaluation toolkit for LLM applications, from synthetic test data through production monitoring.
- 20
AutoGen
Free plan LinuxMacWindows - 21
Google Gemini API
Free plan Web - 22
GroqCloud
Free plan Web - 23
Cohere North
Paid Self-hostedWebNorth combines enterprise search, agent automation, natural-language application building, and deployment flexibility. Its custom pricing and enterprise focus make sales consultation part of adoption.
- 24
Fireworks AI
Paid APISelf-hostedWeb5.7 Visit site - 25
Hugging Face Inference Endpoints
Paid APIWeb
#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price