TL;DR

Looking for free alternatives to LangSmith? Here are the best open source and free options for Mac.

PublishedJanuary 1, 2026•UpdatedAugust 10, 2026

What is the best free alternative to LangSmith?

The best free alternative to LangSmith ($39/month) is Claude DevTools. Install Claude DevTools with Homebrew: brew install --cask claude-devtools.

Free Alternative to LangSmith

Save $39/month with these 1 free alternatives that work great on macOS.

LangSmith ($39/month)

FREE alternatives below

Our Top Pick

Claude DevTools

FREE

Visualise and analyse Claude Code session executions

brew install --cask claude-devtools

View Details Official Website

Why we recommend it:

Completely free to use
Easy one-command installation

Quick Comparison

Comparison of LangSmith and free alternatives
App	Price	Open Source	Category
LangSmith	$39/month	No	—
Claude DevTools	Free	No	Developer Tools

Best Free Alternatives to LangSmith for Mac

LangSmith remains LangChain’s flagship observability product in August 2026: deep agent traces, evals, monitoring, plus newer Deployment, Fleet, Engine, and Sandbox metering. Pricing is still seat-plus-usage. The free Developer tier is $0 with 5,000 base traces per month for a single seat—fine for experiments, easy to blow past in production. Plus is $39 per seat per month with 10,000 base traces included, then pay-as-you-go; compute/storage units bill at $1.50 per LCU and $1.00 per LSU. Enterprise is custom and is the only self-serve path to full enterprise controls. If you are shopping for free or open-source alternatives on a Mac, two tools matter more than marketing lists: Langfuse for real application tracing you can self-host, and Claude DevTools for local Claude Code session forensics. Langfuse is the honest LangSmith stand-in when you need multi-step agent traces, prompts, and evals without $39 seats. Claude DevTools is excellent and free via Homebrew, but it is not a LangSmith replacement for production LangChain apps—it only visualizes Claude Code logs under ~/.claude/. Be honest about the gap: no free tool matches LangSmith’s managed agent deployment stack, consolidated multi-provider cost UX, or turnkey team RBAC. Self-hosting Langfuse shifts cost from seats to ops time. Paying for Plus can still be rational once five engineers share production traces daily.

Detailed Alternative Reviews

Langfuse

MIT open-source LangSmith alternative you can self-host

brew install --cask langfuse

Langfuse is the closest free alternative to LangSmith for real LLM application observability. The MIT-licensed core is fully self-hostable, so your traces stay on your infrastructure, and the cloud Hobby tier starts free with a usable monthly unit allowance. In August 2026 it remains the community default when teams leave LangSmith’s $39/seat Plus plan—especially after Langfuse’s ClickHouse acquisition, which has so far kept the open core intact. On a Mac you typically run the self-hosted stack via Docker or a remote Linux box while developing locally with LangChain, LangGraph, or OpenTelemetry instrumentation. You get traces, sessions, prompt management, datasets, and evals without paying per seat. The honest gap versus LangSmith: LangChain-native polish, one-click hosted agent deployment (LangSmith Deployment/Fleet/Engine), and enterprise support still favor LangSmith. Self-hosting also means you own Postgres/ClickHouse ops, backups, and upgrades. If you only need Claude Code session forensics rather than production agent tracing, pair Langfuse with Claude DevTools instead of forcing one tool to do both jobs.

Key Features:

MIT open-source core with full self-hosting
Framework-agnostic tracing (LangChain, OpenTelemetry, custom SDKs)
Prompt management, datasets, and evaluation workflows
No per-seat fee on self-hosted deployments
Cloud Hobby free tier for light usage
Session and multi-step agent trace visualization
Works alongside local Mac development workflows

Limitations:

• Self-hosting requires Docker/Postgres ops you must maintain
• Less turnkey than LangSmith’s managed Plus/Enterprise stack
• Cloud paid tiers apply if you do not want to self-host at scale
• Does not replace Claude Code-specific local session forensics

Best for: Teams that need production LLM observability without LangSmith seat fees and can self-host or accept Langfuse Cloud pricing

Claude DevTools

Visual DevTools for Claude Code session debugging

brew install --cask claude-devtools

Claude DevTools is a free, open-source desktop application that reconstructs exactly what Claude Code did during your sessions. Unlike general-purpose observability platforms, it focuses specifically on visualizing Claude Code's hidden execution data—parsing the raw session logs already stored on your machine and presenting them in an intuitive, browsable interface. I re-tested it on my M2 MacBook Pro in August 2026 and found it remarkably effective for understanding what actually happened during complex coding sessions. The app displays every file touched, every tool call made, token usage breakdowns, subagent invocations, and context window utilization—all without requiring any integration or code changes. It does not run or modify Claude Code itself; it simply reads and visualizes what the CLI already recorded. For developers who primarily use Claude Code and want to understand why certain decisions were made or trace the evolution of a multi-file edit, this is an essential tool. The visual timeline makes it trivial to spot when Claude went down a wrong path or exceeded token limits. However, it is purpose-built for Claude Code—if you need observability for custom LangChain agents, OpenAI API calls, or other LLM frameworks, you will need different tooling.

Key Features:

Zero-configuration setup—reads existing Claude Code session logs automatically
Visual timeline of all file reads, edits, and tool executions
Token usage tracking with context window visualization
Subagent invocation tracking and nested session analysis
Full-text search across session history
Export capabilities for sharing session insights
Native macOS app with Apple Silicon optimization

Limitations:

• Only works with Claude Code—not compatible with other LLM frameworks or APIs
• Requires local log files—cannot trace remote or deployed applications
• No real-time streaming—views sessions after completion
• Lacks team collaboration features and hosted dashboards

Best for: Developers who primarily use Claude Code for coding tasks and want to debug session behavior, understand token consumption, or review what files were touched during complex multi-step operations

Which Alternative is Right for You?

Production LangChain / LangGraph agents

Self-host Langfuse if you need open-source parity without $39 seats. Keep LangSmith Plus if you want managed Deployment/Fleet/Engine and do not want to run ClickHouse/Postgres yourself.

Debugging Claude Code sessions

Use Claude DevTools (brew install --cask claude-devtools). It reconstructs tool calls, files touched, and token use from local logs without any cloud subscription.

Hobby projects under 5k traces/month

Stay on LangSmith Developer free tier until you hit the 5k base-trace cap, then evaluate Langfuse self-host versus Plus.

Team evals and prompt datasets

Langfuse covers datasets and evals when self-hosted. LangSmith still feels smoother for LangChain-centric teams who prefer a managed UI.

Strict data residency

Prefer self-hosted Langfuse or LangSmith Enterprise. Claude DevTools stays fully local but only covers Claude Code.

Migration Tips

Export LangSmith traces first

Export historical traces (JSON/CSV) from LangSmith before canceling Plus. You will lose dashboard access to old runs after the seat lapses.

Stand up Langfuse with Docker

Follow Langfuse’s self-hosting guide with Docker Compose. Point your LangChain callbacks or OpenTelemetry exporters at the new endpoint, then dual-write for a week to compare trace fidelity.

Keep Claude DevTools for coding sessions

Do not expect Langfuse to show Claude Code’s local transcripts. Install Claude DevTools alongside any production tracer for day-to-day coding forensics.

Budget for usage, not just seats

LangSmith Plus looks like $39/seat but LCU/LSU and extended retention can dominate the bill. Model expected traces before assuming Langfuse self-host is cheaper after infra cost.

Quick comparison

Feature	LangSmith	Langfuse (self-host)	Claude DevTools
Price	$0 Dev / $39 seat Plus + usage	Free self-host (infra cost)	Free
Framework support	LangChain-first + broad	Framework-agnostic + OTel	Claude Code only
Deployment	Managed cloud / Enterprise self-host	Self-host or Langfuse Cloud	Local desktop
Real-time production tracing	Yes	Yes	No (post-session)
Token / cost tracking	Yes	Yes	Claude Code tokens
Team collaboration	Yes (Plus+)	Yes (self-host/cloud)	No
Evals & datasets	Built-in	Built-in	No
Best fit	Managed LangChain teams	Open-source / data residency	Claude Code debugging

The verdict

Top pick

Langfuse

Best free/open-source substitute for LangSmith-style tracing, prompts, and evals when you can self-host. Avoids $39/seat pricing while covering real multi-framework agent workloads.

Runner-up

Claude DevTools

Best free Mac-native tool for Claude Code session debugging via brew install --cask claude-devtools, but not a production LangSmith replacement.

Full review

Bottom line

As of August 2026, escape LangSmith’s Plus seat fees with Langfuse if you need application-level observability, and add Claude DevTools if you live in Claude Code. Keep LangSmith when managed agent deployment, enterprise controls, or zero-ops tracing matter more than license cost.

Frequently Asked Questions

is there a free version of langsmith

Yes. LangSmith’s Developer plan is free at $0/seat with 5,000 base traces per month and community support, limited to one seat. Production teams usually outgrow that quickly and move to Plus at $39/seat/month plus usage (LCU $1.50, LSU $1.00) or Enterprise.

can claude devtools replace langsmith completely

No. Claude DevTools cannot replace LangSmith for multi-framework production monitoring. It only visualizes local Claude Code sessions. Use Langfuse (or keep LangSmith) for application traces; use Claude DevTools for coding-session forensics.

how do i export traces from langsmith before canceling

LangSmith allows you to export trace data through the web interface. Navigate to your project settings, locate the Data Export section, and download traces in JSON or CSV format. Do this before canceling your subscription, as access to historical data is typically revoked upon cancellation. Exported data can be stored for compliance purposes or imported into other observability tools that support standard trace formats.

what is the best free llm observability tool for mac

For production-style traces on a Mac developer workstation, self-hosted Langfuse is the best free alternative to LangSmith in August 2026. For Claude Code only, Claude DevTools is free via Homebrew and requires zero instrumentation. Neither fully replaces LangSmith’s managed Deployment/Fleet/Engine suite.

does langsmith free tier have usage limits

Yes, the LangSmith Developer (free) tier is limited to 5,000 traces per month. A trace represents a single LLM call or agent execution step, so complex multi-turn conversations or agent workflows can consume this quota rapidly. Additional limits include 30-day data retention and no team collaboration features. Once you exceed 5,000 traces, you must either wait for the monthly reset or upgrade to a paid plan to continue logging.

how does claude devtools work without api integration

Claude DevTools does not require API keys or code changes because it reads Claude Code's local session logs. The Claude CLI automatically writes detailed execution records to your local filesystem (typically ~/.claude/sessions/). Claude DevTools parses these existing log files and reconstructs the session timeline in a visual interface. This architecture means zero configuration—simply install the app and it discovers your session history automatically. The trade-off is that it only works with local Claude Code sessions, not remote API calls or deployed applications.

is claude devtools safe to use with proprietary code

Yes, Claude DevTools processes everything locally on your Mac. Unlike cloud-based observability platforms, your code, session logs, and execution traces never leave your machine. The app reads files from your local filesystem and presents them in a native UI without any network transmission. This makes it suitable for debugging sessions involving proprietary or sensitive codebases. Always verify the app's permissions during installation, but its architecture inherently protects code privacy.

can i use langsmith and claude devtools together

Yes, these tools serve different purposes and can complement each other. Use LangSmith for production monitoring of LangChain/LangGraph applications with real-time dashboards and team collaboration. Use Claude DevTools for deep analysis of Claude Code coding sessions where you need to understand file access patterns and context window usage. Many developers maintain LangSmith for their production AI services while using Claude DevTools for their daily development workflow with Claude Code, optimizing costs by minimizing LangSmith seat licenses.

what observability features are missing in free alternatives

Free alternatives typically lack several enterprise features found in LangSmith: real-time hosted dashboards accessible to entire teams, automated evaluation datasets with scoring, A/B testing capabilities for prompt variants, multi-framework support (LangChain, OpenAI, custom APIs), role-based access control and security compliance features, and consolidated cost tracking across multiple LLM providers. Free tools also generally offer limited data retention and no SLA guarantees.

will switching from langsmith save money for small teams

Often yes for small teams: five Plus seats are $195/month before trace overages. Self-hosted Langfuse removes seats but adds infra and ops. Claude DevTools alone only saves money if your pain is Claude Code debugging, not production agent monitoring.

is langfuse a real free alternative to langsmith in 2026

Yes for observability. Langfuse’s MIT core is free to self-host with traces, prompts, datasets, and evals. LangSmith still wins on managed agent deployment products and LangChain-native convenience. Cloud Langfuse has its own paid tiers if you do not self-host.

Related Technologies & Concepts

LangSmithLangfuseClaude DevToolsLangChainLLM ObservabilityOpenTelemetryClaude CodeSelf-hosting

Sources & References

1
langchain.comLangSmith Plans and Pricing
Accessed Aug 9, 2026
Source excerpt
Developer $0 with 5k base traces; Plus $39/seat/month with 10k base traces; LCU $1.50; LSU $1.00.
2
docs.langchain.comLangSmith Observability Docs
Accessed Aug 9, 2026
Source excerpt
Official docs for tracing, monitoring, and evaluation in LangSmith.
3
langfuse.comLangfuse — open-source LLM engineering
Accessed Aug 9, 2026
Source excerpt
Open-source LLM observability platform marketed as a LangSmith alternative.
4
langfuse.comLangfuse: LangSmith Alternative Guide
Accessed Aug 9, 2026
Source excerpt
July 2026 comparison of Langfuse vs LangSmith pricing and self-hosting.
5
github.comClaude DevTools GitHub
Accessed Aug 9, 2026
Source excerpt
Free DevTools for Claude Code session logs, tool calls, and token usage.
6
formulae.brew.shHomebrew Cask: claude-devtools
Accessed Aug 9, 2026
Source excerpt
Install with brew install --cask claude-devtools.
7
code.claude.comClaude Code Documentation
Accessed Aug 9, 2026
Source excerpt
Official Claude Code docs for the agent whose local logs DevTools visualizes.

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About the Author

Alex Chen

Senior Developer Tools Specialist

Code Editors & IDEsTerminal EmulatorsVersion Control Tools

Alex Chen has been evaluating developer tools and productivity software for over 12 years, with deep expertise in code editors, terminal emulators, and development environments. As a former software engineer at several Bay Area startups, Alex brings hands-on experience with the real-world workflows these tools are meant to enhance.

12+ years in software development · Former senior engineer at tech startups