LangChain

langchain.com ↗

Open agent engineering platform and open source frameworks for building agents.

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SI Score: 80/100
Pricing: Not confirmed
Free plan: Not confirmed
Sign-up required: Not confirmed

Ask SI about LangChain

Answers use saved listing facts and recorded sources.

Homepage screenshot

SI REVIEWBased on the site's own pages, in a directory managed by people

What it does

LangChain provides open source, model-agnostic harnesses for building agents, including LangChain, LangGraph, and Deep Agents. LangSmith is its framework-agnostic platform for testing, deploying, monitoring, and improving agents. The site lists products for agent observability, evaluation, deployment, sandboxes, LLM gateway, and no-code agents with Fleet. Users can start with LangSmith for free, get a demo, or read documentation.

LangChain started as Harrison Chase's side project in late 2022. The company began in early 2023 with co-founder Ankush Gola. The about page says it launched LangGraph, then LangSmith, and most recently Deep Agents. It is headquartered in San Francisco with offices in New York, Boston, and Amsterdam.

Best for

Building agents with open source frameworksTesting and monitoring agentsDeploying agents in productionBuilding no-code agents with Fleet

SI Score

80/100

#1 in Coding & AI Platforms

Based on published information. No hands-on task test.

Method 2.0 · Published source review Assessed Oct 28, 2026Score ceiling for this evidence: 84/100.

Product usefulness 80

Evidence

LangChain's platform documents building agents, turning traces into evaluation datasets, deploying and monitoring them, then feeding fixes back into testing. Governance includes spend controls and human approval for sensitive actions. Those explicit execution boundaries support a complete agent-development workflow, without treating test tooling as proof that an agent is reliable.

Limits: Source-researched AI assessment reviewed by a separate native AI worker. No hands-on product test or human verification is claimed.

Source links and check dates are in Sources and checks below.

Separate website checks

These checks do not add points to the SI Score. They inspect the website's HTML, not the product in use.

Basic website checks100/100

HTTPS: yes
Homepage answered with HTTP 200
Privacy policy link: found
Terms link: found
Contact or about page: found

We check that these pages exist, not what they say. Ownership and company details are not verified.

Checked Oct 18, 2026.

HTML accessibility checks87/100

Page language set: en
Mobile viewport: yes
Images with a text alternative: 60 of 95
Main heading (h1): yes

Automated checks on the homepage HTML only. This is not a full accessibility audit.

Checked Oct 18, 2026.

Homepage HTML response100/100

First byte after 37 ms
Homepage HTML loaded in 0.1 s
HTML size 266 KB

Measured once from our server. Images, scripts and your own connection are not included.

Checked Oct 18, 2026.

Trackers in homepage HTML88/100

Third-party trackers in the homepage code: Google Tag Manager

Only the homepage HTML is checked. Trackers loaded later by scripts, and what the service does with your data, are not covered.

Checked Oct 18, 2026.

Page date hints90/100

No copyright year found on the page.
Server says last modified: Sat, 17 Oct 2026 00:23:25 GMT

A copyright year is a weak sign of upkeep. It does not prove the content is current.

Checked Oct 18, 2026.

Policy links do not verify a company's conduct. An HTML response time is not application speed. Tracker and accessibility checks miss behavior after page load. Copyright dates do not prove product upkeep.

How the SI Score works →

Unconfirmed details may be unassessed, absent from the pages checked or temporarily unreadable. A missing price does not mean the service is free.

Sources and checks

Supporting pages for product usefulness, site facts, prices and separate website checks. Each record keeps its own date. Reading a page does not establish how well the product performs in use.

www.langchain.com/
- Product usefulness evidence
- Basic website checks (separate check)Checked Oct 18, 2026
- HTML accessibility checks (separate check)Checked Oct 18, 2026
- Homepage HTML response (separate check)Checked Oct 18, 2026
- Trackers in homepage HTML (separate check)Checked Oct 18, 2026
- Page date hints (separate check)Checked Oct 18, 2026
www.langchain.com/privacy-policy
- Basic website checks (separate check)Checked Oct 18, 2026
www.langchain.com/terms-of-service
- Basic website checks (separate check)Checked Oct 18, 2026

Checks without a source link

PricingUnknownChecked Oct 18, 2026
Free planUnknownChecked Oct 18, 2026
Sign-up requiredUnknownChecked Oct 18, 2026
PlatformsUnknownChecked Oct 18, 2026
APIUnknownChecked Oct 18, 2026
Open sourceUnknownChecked Oct 18, 2026

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