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LangWatch

AI agent testing and LLM evaluation platform

LangWatch is an AI agent testing, LLM evaluation, and observability platform for production AI teams. It combines traces, evaluations, scenario simulations, guardrails, prompt management, and Optimization Studio/DSPy workflows, with cloud and self-managed options for teams that need release-quality feedback loops.

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About LangWatch

About LangWatch

LangWatch is currently framed as an AI agent testing, LLM evaluation, and observability platform with tracing, simulations, guardrails, prompt management, and optimization workflows. The current site and docs emphasize traces, evaluations, scenario tests, simulations, prompt management, guardrails, Optimization Studio, DSPy optimization, Developer Free, Growth, and Enterprise/Regulated plans; GitHub reports an active Apache-2.0 repository.

Best-fit usage: production AI teams want traces, evals, datasets, prompts, and guardrails to become part of release discipline. The tool page should guide readers toward that workflow while making the major limitation clear: treating a sophisticated evaluation platform as a passive dashboard without assigning ownership for instrumentation, datasets, failure review, and release gates.

Procurement note: Developer Free is a starting point, Growth includes event/seat/usage/retention dimensions, and Enterprise or Regulated plans cover custom hosting, SSO/RBAC, audit, retention, uptime, and support requirements. If this becomes part of a production workflow, compare alternatives by the exact job to be done and verify data handling, support, and exit paths.

Pricing & Platform Specs

Pricing Summary

Open-source core (Apache-2.0 license) for self-hosted LLM observability, guardrails, and agent evaluations with $0 software license fees. LangWatch Cloud offers a Developer Free tier ($0/mo, 50k events/mo, 2 seats, 14-day retention), Growth tier ($34/core-seat/mo with 200k events/mo included, $6/100k overage, 30-day retention, unlimited lite-users, and private Slack support), and Enterprise custom tiers (VPC/On-premise deployment, custom data retention, SAML 2.0 SSO, granular RBAC, audit logs, and dedicated 99.9% Uptime SLAs).

full pricing breakdown →

Supported Platforms

Cloud and self-managed platform with tracing, evaluations, scenario tests, simulations, guardrails, prompt management, OpenTelemetry-oriented instrumentation, and SDK/docs support.

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Alternatives

All LangWatch alternatives →
Beszel logo

Beszel

Lightweight server monitoring with Docker stats and alerts

Beszel is a lightweight, self-hosted server monitoring platform built in Go that tracks CPU, memory, disk, network, GPU, temperature, and Docker container metrics with historical data visualization and configurable alerts. Its simple hub-and-agent architecture deploys in minutes and consumes minimal resources compared to traditional monitoring stacks like Prometheus and Grafana.

freeOpen Source
TensorZero logo

TensorZero

Open-source LLM gateway with built-in optimization and A/B testing

TensorZero is an open-source LLMOps platform in Rust that unifies an LLM gateway, observability, prompt optimization, and A/B experimentation in a single binary. It routes requests across providers with sub-millisecond P99 latency at 10K+ QPS while capturing structured data for continuous improvement. Supports dynamic in-context learning, fine-tuning workflows, and production feedback loops. Backed by $7.3M seed funding, 11K+ GitHub stars.

freeOpen Source

Community experience

Sources & verification

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Content verified

Verification dates are editorial checks. Routine CMS saves and automatic updatedAt timestamps do not advance them.

FAQ

What is LangWatch?

LangWatch is an AI agent testing, LLM evaluation, and observability platform for production AI teams. It combines traces, evaluations, scenario simulations, guardrails, prompt management, and Optimization Studio/DSPy workflows, with cloud and self-managed options for teams that need release-quality feedback loops.

Is LangWatch free?

LangWatch offers a free tier alongside paid plans. Open-source core (Apache-2.0 license) for self-hosted LLM observability, guardrails, and agent evaluations with $0 software license fees. LangWatch Cloud offers a Developer Free tier ($0/mo, 50k events/mo, 2 seats, 14-day retention), Growth tier ($34/core-seat/mo with 200k events/mo included, $6/100k overage, 30-day retention, unlimited lite-users, and private Slack support), and Enterprise custom tiers (VPC/On-premise deployment, custom data retention, SAML 2.0 SSO, granular RBAC, audit logs, and dedicated 99.9% Uptime SLAs).

Is LangWatch open source?

Yes — LangWatch is open source.

Is LangWatch still maintained?

Yes — LangWatch is active. Its listing was last verified on September 6, 2026.

What are the best LangWatch alternatives?

The first editor-selected LangWatch alternatives are Beszel, TensorZero.

How does LangWatch score in our review?

The published editorial review lists LangWatch at 78/100 overall across speed, privacy, and developer experience. Check the review's evidence status and test metadata for its verification level.