Best Alternatives to telemetry.dev in 2025
telemetry.dev gives teams a clean, trace-first view of AI agent runs, with spans for every model and tool call, prompt editing without deploys, dataset evals, and production score comparisons. It is a strong fit for agent-centric observability, but different teams have different priorities around open-source control, framework depth, enterprise governance, or cost. Here are the best alternatives to telemetry.dev, based on what each does best.
Langfuse
Observability and analytics for LLM apps
Best open-source alternative for teams that want self-hosting and data ownership. Langfuse offers tracing, prompt management, evals, and datasets with a permissive license and a large community. It is a strong pick if you need to run observability inside your own VPC or avoid vendor lock-in, though its agent-specific trace UX is less opinionated than telemetry.dev.
LangSmith
Best for teams already building on LangChain or LangGraph. LangSmith provides deep framework-native tracing, prompt versioning, dataset evals, and annotation queues, with tight integration into the LangChain ecosystem. Choose it if your stack is LangChain-centric and you want first-party support, but expect less flexibility if you use other orchestration frameworks.
Arize Phoenix
Best open-source option for ML and LLM evaluation depth. Phoenix offers strong tracing plus robust eval and drift analysis, with OpenTelemetry-based instrumentation and a free self-hosted path. It suits teams that want rigorous offline and online evaluation alongside observability, though its agent-run visualization is less streamlined than telemetry.dev's single-trace view.
Helicone
Best for fast, low-friction setup with a proxy-based approach. Helicone captures requests at the gateway level, giving instant logging, cost tracking, caching, and rate limiting with minimal code changes. It is ideal for teams that want quick visibility and cost controls without deep instrumentation, but it offers less structured agent and tool-call tracing than telemetry.dev.
Braintrust
Best for eval-first workflows. Braintrust combines logging, datasets, scoring, and prompt playgrounds with a strong emphasis on experimentation and CI-style evaluation. Teams that treat evals as the core of their quality process will appreciate its workflow, though its observability view is less focused on live agent run tracing than telemetry.dev.
W&B Weave
Best for teams already using Weights & Biases. Weave adds LLM and agent tracing, evaluation, and monitoring inside the W&B platform, making it convenient if your ML workflows already live there. It is a solid choice for unified ML and LLM observability, but it is less specialized for agent-specific cost and error alerting than telemetry.dev.
Datadog LLM Observability
Best for enterprises standardizing on Datadog. It brings LLM and agent traces into existing dashboards, alerts, and APM workflows, with strong governance and integrations. Choose it if operational consolidation matters more than specialized agent tooling, though it is heavier and pricier than telemetry.dev for pure AI-agent observability.
telemetry.dev stands out for its agent-first trace model, combining spans, prompt editing, evals, and production score comparisons in one place. Langfuse and Arize Phoenix are the strongest open-source alternatives, LangSmith wins for LangChain-native teams, Helicone is fastest to adopt, Braintrust leads on eval-centric workflows, and Datadog fits enterprises wanting consolidated observability. Pick based on whether your priority is data ownership, framework fit, evaluation depth, setup speed, or enterprise integration.