Free open source alternative app list of LLM Observability :

Langfuse

Key features Open-source LLM engineering platform for AI-powered applications. Tracing and observability tools to debug and analyze LLM requests. Monitoring capabilities for production LLM-based products. Built-in evaluation features to assess and improve model performance. Prompt management to organize, version, and maintain prompts. Platforms: Linux, macOS, Windows Links Official website Source code repository Pricing Free. The entire platform is open source under the MIT license and free to self-host with no feature restrictions.

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Arize Phoenix

Key features Open-source LLM tracing and evaluation platform for AI applications. Monitor, debug, and optimize LLM workflows with built-in observability. Self-hosted deployment for full control over tracing and evaluation data. Supports experimentation with LLM tracing and evaluation using the Phoenix library. Designed for machine-learning and AI observability use cases. Platforms Windows, macOS, Linux Links Official website Source code repository Pricing Free. The free plan includes self-hosted LLM tracing, evaluation, and experimentation with the open-source Phoenix library.

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Helicone

Key features Open-source LLM observability and monitoring platform built for AI applications. Tracks LLM requests to help developers understand usage patterns and behavior. Monitors costs associated with AI application usage. Measures latency and performance for model calls. Evaluates quality metrics to assess model outputs and application reliability. Platforms: Linux Links: Official website · Source code Pricing: Free self-hosted open-source license (Apache-2.0) with full observability features; cloud managed service available with a free tier.

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OpenLIT

Key features Open-source observability platform purpose-built for LLM applications. Combines monitoring, debugging, and analytics in one integrated tool. Native OpenTelemetry support for standardized telemetry collection. Self-hosted deployment with no usage limits. Licensed under Apache-2.0, so it's free to use and extend. A free, open-source alternative to commercial tools like LangSmith. Platforms Linux, macOS, Windows. Links Official website: https://openlit.ai Source code: https://github.com/openlit/openlit Pricing Free and open-source under Apache-2.0, self-hosted with no usage limits.

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OpenLLMetry

Key features Open-source observability tool designed specifically for LLM applications. Provides tracing, metrics, and performance monitoring to help debug and optimize AI workflows. Self-hosted LLM observability with full telemetry capabilities. Licensed under Apache-2.0, enabling free use and modification. Platforms: Windows, macOS, Linux Links Official website: https://www.traceloop.com/openllmetry Source code: https://github.com/openllmetry/openllmetry Pricing: Free. OpenLLMetry is free and open-source under the Apache-2.0 license, offering self-hosted LLM observability with tracing and monitoring capabilities.

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Latitude

Key features End-to-end tracing for LLM applications and AI agents in production. Monitoring and analytics tools built specifically for LLM observability. Self-hosted, open-source platform with full control over your data. Designed for AI-agent workloads, covering request-level visibility and debugging. Platforms: Linux, macOS, Windows. Links Official Website Source Code Pricing: Free. Open-source self-hosted observability for AI agents, including full tracing and analytics.

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