langchain.com website review

About 1.1 MB of JavaScript is downloaded but never used on this page. Google estimates it would make the page about 1.4 s faster on a phone.

3 files block the first paint until they finish downloading. Deferring or inlining them could save about 2.3 s.

About 256 KiB of CSS is downloaded but never applied on this page. Google estimates it would make the page about 1.2 s faster on a phone.

Your mobile performance score is 43. Under 50 is Google's “poor” band: many phone visitors leave before the page is usable.

A phone's processor spends 5.3 s on main-thread work while loading, 2.6 s of it running JavaScript. Above 2 s, taps and scrolls feel sluggish.

8 third-party services load with your homepage (Google Tag Manager, website-files.com and Facebook and others), adding 3.3 MB and 1.5 s of main-thread time.

33 files are served with short cache lifetimes, so returning visitors download them again (736 KiB).

website-files.com costs a phone 475 ms of main-thread work and 1.1 MB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Google Tag Manager costs a phone 493 ms of main-thread work and 735 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

20 long tasks block the main thread while loading, the longest for 414 ms. During a long task the page ignores taps.

4 images could be 94 KiB smaller with modern formats (WebP or AVIF) and sizes that fit a phone screen. Google estimates it would make the page about 300 ms faster on a phone.

chilipiper.com costs a phone 131 ms of main-thread work and 975 KiB of downloads while your page loads. Loading it after the page is usable, or only on the pages that need it, takes that off the critical path.

Polyfills for old browsers add 62 KiB JavaScript that modern phones do not need.

Critical files load one after another instead of in parallel (3 chains). Preconnecting to key origins and preloading the hero image shortens the chain.

Scripts make the browser recalculate the layout repeatedly while the page loads, which wastes processor time on phones.

5 KiB could be saved by minifying JavaScript.

Real Chrome users on phones do not pass Google's Core Web Vitals on this page (28-day field data from the Chrome UX Report (opens in a new tab)). Google uses this in ranking.

The page becomes fully interactive after 26.7 s. Good is under 3.8 s.

Your largest element takes 8.3 s to render on a phone. Google's threshold for “good” is 2.5 s. The largest element is the image.

Scripts block taps and scrolling for 1.4 s in total while the page loads. Good is under 200 ms.

Visually, the page fills in at 6.5 s (Speed Index). Good is under 3.4 s.

Real visitors wait 3.4 s for the largest content to appear (75th percentile). Good is under 2.5 s.

Real visitors see the first content after 2.9 s (75th percentile). Good is under 1.8 s.

16 images have no width and height attributes, so the layout jumps as each one loads.

The first text or image appears after 1.8 s on a phone. Good is under 1.8 s.

Over the last 25 four-week periods to 2026-11-07, real Chrome visitors' tap response (inp) went from 156 ms to 154 ms at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Over the last 25 four-week periods to 2026-11-07, real Chrome visitors' largest content (lcp) went from 2.5 s to 2.4 s at the 75th percentile (Chrome UX Report (opens in a new tab) history).

Your homepage downloads 4.0 MB in 194 requests on a phone: scripts 3.0 MB (63), images 362 KiB (43) and stylesheets 268 KiB (3). Under 2 MB keeps phones on slow connections fast.

6a5f7558c1d15e92505400db_newton-rocket-p-500.avif is on the first screen but marked loading="lazy", so the browser waits before fetching it and the page looks finished later. Load it eagerly (and give it fetchpriority="high" if it is the main image).

By the Sustainable Web Design model, a visit to your homepage emits about 1.13 g of CO₂e: 135.2 kg a year at 10,000 visits a month. It scales with page weight, so every byte cut lowers it.

43 text elements don't have enough contrast against the background to read easily, especially outdoors on a phone.

28 tap targets are too small or too close together to hit reliably with a finger.

Scrollable region must have keyboard access: 1 element on the page fails this check, rated serious by axe-core.

All page content should be contained by landmarks: 1 element on the page fails this check, rated moderate by axe-core.

3 visible links have no text or label, so screen readers cannot say where they go.

1 form field has no label, so screen readers announce an empty box and autofill guesses.

ARIA role should be appropriate for the element: 5 elements on the page fail this check, rated minor by axe-core.

Headings skip levels (h3 → h5 and h2 → h6), which makes the page harder to scan with a screen reader.

No structured data (JSON-LD), so Google can't show rich results such as your logo, ratings or FAQs.

The homepage links to 66 pages on langchain.com and 37 external pages.

There is no Organization (or LocalBusiness) JSON-LD, so search engines and AI assistants have no machine-readable facts about who runs the site: its name, logo, profiles and contact details.

There is no /llms.txt, a short Markdown guide to your key pages for AI tools (llmstxt.org). It is optional and few AI tools read it yet, so treat it as a cheap extra.

/blog has no <h1> headline, so visitors and search engines get no clear main topic.

We fetched 15 pages linked from your homepage (of 30 found) and read each the way a search engine does.

6 errors were logged to the browser console while the page loaded, for example “Failed to load resource: net::ERR_FAILED”.

No Strict-Transport-Security header, so browsers may still try plain http first on a return visit.

No Referrer-Policy header, so full URLs can leak to the sites you link to.

No Permissions-Policy header to switch off camera, microphone and location for embedded content.

There is no /.well-known/security.txt telling researchers how to report a security problem to you.

No phone number or email link on the homepage, so ready-to-buy visitors have one fewer way to reach you.

No guarantee or risk reducer (money-back, free trial, no credit card) is mentioned, which is often what tips a hesitant visitor.

The homepage carries about 430 words of visible text.

Email authentication: SPF record 25 points, plus 15 when it ends in -all (10 for ~all); DMARC record 25, plus 25 for a reject policy (15 for quarantine); a DKIM key on a common selector 10.

Before a visitor clicks anything, the page loads Google Ads, Google Analytics, Google Tag Manager, HubSpot and LinkedIn Insight and 4 mores (measured from a US location before any click). A consent tool (CookieYes) is installed; check it blocks these until visitors agree where the law requires it.

Opening the homepage sets 18 cookies, 2 of them by other companies (measured from a US location before any click).

Loading the homepage contacts 57 hosts run by other companies (fonts, scripts, analytics, ads), each of which sees the visitor's IP address.