Compare tools side by side · TechInTrends

LangChain's hosted platform for tracing, evaluating and monitoring LLM apps and agents, framework-agnostic.

Open-source LLM engineering platform for traces, evals, prompt management and metrics; now part of ClickHouse.

Open-source AI observability and evaluation tool built on OpenTelemetry and OpenInference.

Evaluation-first AI platform where production traces become datasets and regression tests.

Head to head

Metric	LangSmith	Langfuse	Arize Phoenix	Braintrust
Stars	n/a	37.3k	12.2k	n/a
Weekly downloads	21.2M	7.4M	117k	3.2M
Download growth	+19%	+32%	-4%	+63%
Popularity score	90/100	84/100	68/100	80/100
Forks	n/a	4.2k	1.3k	n/a
Open issues	n/a	1.2k	1.2k	n/a
Last commit	n/a	today	4d ago	n/a
Latest version	0.14.17Nov 2, 2026	5.2.0Nov 5, 2026	21.0.0Oct 30, 2026	3.44.0
First released	n/a	2023	2022	n/a
Signals	Popular	TrendingPopular	None	Rising
Listed in	AI & Machine Learning › LLM Observability & Evals	AI & Machine Learning › LLM Observability & Evals	AI & Machine Learning › LLM Observability & Evals	AI & Machine Learning › LLM Observability & Evals

Weekly downloads over time

Hover for exact values; switch to log scale for tools of very different sizes. Not shown (no comparable download data): Braintrust.

LangSmith
Langfuse
Arize Phoenix