← Analyze a URL · Tested sites

www.duolingo.com

Report from 7/24/2026, 12:18:28 PM https://www.duolingo.com
Latest run · lab, cold cache
0
7/24/2026
28-day score · p75 · the standard
0
9 runs
CRR0%latest
SSD64%latest
TC137 toklatest

Scored by v3 · source-of-truth hashes: score db860d6ac94e · thresholds e94f8b33e500 — verifiable against the canonical scorer.

The 28-day score is the p75 of nightly runs — the stable number to cite. Deterministic metrics (CRR/SSD/TC) show their latest value (they move only when the site changes); timing (TTFUT) and answer-fidelity (AF) are smoothed by 28-day p75 — the same lab-vs-field split Core Web Vitals uses. Synthetic daily measurement, not real-user field data.

Core Agent Vitals badge  Embed this badge

Show your agent-readiness score anywhere — it links back to this report.

[![Core Agent Vitals](https://agentvitals.dev/badge/duolingo.com.svg)](https://agentvitals.dev/results?url=https%3A%2F%2Fwww.duolingo.com)
<a href="https://agentvitals.dev/results?url=https%3A%2F%2Fwww.duolingo.com"><img src="https://agentvitals.dev/badge/duolingo.com.svg" alt="Core Agent Vitals" height="20"></a>
What AI tells your customers about youAgent confidence: LOW
🟡Business nameDuolingo · guessed from page text (no structured data)
❌Categorynot found
➖Pricenot applicable · not applicable to this page type
➖Locationnot applicable · not applicable to this page type
➖Hoursnot applicable · not applicable to this page type
➖Productsnot applicable · not applicable to this page type
🟡DescriptionDuolingo is the world's most popular way to learn a language. It's 100% free, fun and science-based. Practice online on duolingo.com or on the apps! · guessed from page text (no structured data)

An agent is likely to fabricate missing details rather than say “I don’t know”. 0/3 applicable facts come from machine-readable structured data.

DesktopMobile
An agent recovered no usable content from this page without executing JavaScript.
0
Overall score
weighted CAV (0–100)
FAIL
0–4950–8990–100

Metrics

0%
CRR Content Recovery Poor
0.64
SSD Semantic Signal Density Good
137 tok
TC Token Cost Good
—
TTFUT Time to First Useful Token N/A

Token Cost breakdown

Where the page's tokens go (≈4,232 across regions). 83% is non-content — chrome and boilerplate an agent pays for. Add landmark roles (main/nav/header/footer) so agents can skip it.

Content
16.6% · 703
Chrome (nav / header / footer)
83.4% · 3,529
Boilerplate (cookie / ad)
0% · 0
Other
0% · 0

Final screenshot

Final screenshot of https://www.duolingo.com

Diagnostics

high CRR Content is hidden behind JavaScript

pre-JS raw HTML

Evidence100% of content requires JS
ImpactA non-rendering agent never sees the JS-injected content.
Effort1–4 h

Fix: Server-render or statically generate the main content so a non-JS agent still receives it; make client rendering a progressive enhancement, not the source of truth.

high TC 83.4% of tokens are non-content (boilerplate/chrome)

agent representation — token decomposition

EvidenceToken decomposition: content 16.6%, chrome 83.4%, boilerplate 0%, other 0%. Only 16.599999999999994% of the agent's tokens are real content.
ImpactAn agent pays for boilerplate on every request and has less context left for the real content.
Effort30–90 min

Fix: Strip repeated nav/header/footer/cookie chrome from the agent-visible output; wrap content in <main>/<article> so the extractor keeps signal and drops boilerplate.

Rendered profile: headless

Agent Discoverability 71/100 · Needs Work

Access & discovery checks — separate from the gated CAV metrics above. Click an issue for business impact, what we measured, and how to fix. · Take the Agent Readiness course →

Agent files & endpoints

~ llms.txt Found at /llms.txt but missing H1/blockquote Learn →
✓ robots.txt (AI bots) Major AI bots allowed Learn →
~ sitemap.xml Sitemap found but no <url>/<loc> entries Learn →
✗ JSON-LD structured data No JSON-LD found Learn →
✓ agents.json Found at /agents.json Learn →
✓ WebMCP endpoint Found at /webmcp.json Learn →
✓ OpenAPI / API docs Found at /openapi.json Learn →

Issues (4)

~ No content-blocking cookie wall medium impact Consent platform: optanon (verify it doesn't block content)

Business impact A consent wall that hides content until a click is invisible to agents — they cannot click 'Accept'.

What we measured We fingerprint OneTrust, Cookiebot, Usercentrics and similar managers and flag content-blocking ones.

How to fix Use an overlay banner that leaves content in the DOM, not a blocking interstitial.

Spec: https://gdpr.eu/cookies/

~ llms.txt present + valid high impact Found at /llms.txt but missing H1/blockquote

Business impact llms.txt is the robots.txt for AI: it tells agents what your site is, what matters, and where to find it. Without it AI guesses — and guessing means inaccurate recommendations and lost visibility.

What we measured We fetch /llms.txt and /.well-known/llms.txt and validate the spec (H1 title + a one-line blockquote summary). We also note /llms-full.txt (your full content as Markdown).

How to fix Create /llms.txt with a short summary + key pages; optionally /llms-full.txt with full content in Markdown.

Learn how to implement →

# Your Site
> One-line description for AI agents.

## Key pages
- /products — catalog
- /pricing — plans
- /docs — documentation

Spec: https://llmstxt.org

✗ Structured data (JSON-LD) medium impact No JSON-LD found

Business impact Schema.org JSON-LD tells agents what a page IS (product, article, business) with typed fields (price, rating, hours). Without it agents extract less reliably.

What we measured We parse <script type=application/ld+json>, validate it, and check for populated @type fields.

How to fix Add JSON-LD: Organization/LocalBusiness on the homepage, Product on product pages, Article on posts.

Learn how to implement →

<script type="application/ld+json">{"@context":"https://schema.org","@type":"Organization","name":"Your Co","url":"https://example.com"}</script>

Spec: https://schema.org/

~ XML sitemap present medium impact Sitemap found but no <url>/<loc> entries

Business impact A sitemap is your table of contents for AI crawlers. Without it agents follow homepage links and miss deep pages (products, docs, pricing) — shrinking what they can recommend.

What we measured We fetch /sitemap.xml (and /sitemap_index.xml), confirm valid XML with <loc> entries, and check <lastmod> freshness.

How to fix Generate an XML sitemap of all public pages with current lastmod dates and reference it in robots.txt.

Learn how to implement →

# robots.txt
Sitemap: https://example.com/sitemap.xml

Spec: https://www.sitemaps.org/

Passed audits (7)

✓ robots.txt allows AI bots✓ No CAPTCHA wall✓ No login wall on public content✓ Server response (TTFB)✓ agents.json discovery✓ WebMCP endpoint✓ API documentation

Transport & Trust (SEC 1.0.0)

HTTPS, HSTS, CSP, sniffing, referrer and CORS posture. Diagnostic only — this does not affect the CAV score. A security header does not make a page more legible to an agent, so scoring it would reward a CDN toggle that changes nothing an agent can recover. We measure it and say so.

37Transport posture (0–100, unscored)
1pass
1warn
3fail
Per-header findings (6)
HeaderEvidence
✅ HTTPSserved over HTTPS
❌ HSTSno strict-transport-security header
❌ Content-Security-Policyno content-security-policy header
❌ X-Content-Type-Optionsmissing nosniff
⚠️ Referrer-Policyno referrer-policy header (browser default applies)
➖ CORS exposureno CORS headers on the document (normal for an HTML page)
Full profile — how to improve · unused JS · network · timing

How to improve

highProfile reflects a block/challenge page — not your contenthighest leverage

whole profile

EvidenceMeasured against a block/challenge page (a bot-wall/CAPTCHA was served (www.gstatic.com)); every number here describes the wall, not your site.
ImpactAn AI agent hits the same wall and recovers none of your content — fix the block before optimizing anything else.
FixAllowlist legitimate agent user-agents / IP ranges in your WAF or bot-management and serve real content (not a challenge), then re-run.

Third-party impact

132 third-party requests · 3424 KiB (99.4% of transfer) · 2633 ms main-thread — code an agent must also fetch/run before your content settles. Fewer, lazier third-parties = faster, cheaper agent reads.

Third-party domainReqsTransferMain-thread
cloudfront.net981959 KiB1316 ms
googletagmanager.com4653 KiB623 ms
gstatic.com1374 KiB254 ms
facebook.net2158 KiB245 ms
cookielaw.org5152 KiB110 ms
google.com697 KiB35 ms
google-analytics.com221 KiB50 ms
doubleclick.net43 KiB—
tupsrv.com33 KiB—
recaptcha.net22 KiB—
googleadservices.com11 KiB—
onetrust.com10 KiB—

Wasted JavaScript (by bundle)

Transfer-accurate — each bundle's transfer size × its unused %, ranked by wasted bytes (the biggest code-splitting wins). Unused JS also inflates Token Cost (TC).

BundleTransferUnusedWasted
https://www.gstatic.com/recaptcha/releases/A7KpaEASfhDcK0nXxgQEyyYv/recaptcha__en.js 3P374 KiB62.9%235 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/app-b99c4894.js 3P307 KiB62.1%191 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/9951-96351ecb.js 3P238 KiB67%159 KiB
https://www.googletagmanager.com/gtm.js?id=GTM-TX6Z97C 3P175 KiB54.1%94 KiB
https://www.googletagmanager.com/gtag/js?id=G-CSFDVCPQ4F&cx=c&gtm=4e67m0 3P183 KiB47.8%88 KiB
https://accounts.google.com/gsi/client 3P97 KiB82.4%80 KiB
https://www.googletagmanager.com/gtag/destination?id=AW-397119219&cx=c&gtm=4e67m0 3P144 KiB54.9%79 KiB
https://cdn.cookielaw.org/scripttemplates/202404.1.0/otBannerSdk.js 3P109 KiB70.3%77 KiB
https://www.googletagmanager.com/gtag/js?id=AW-728842606&cx=c&gtm=4e67m0 3P151 KiB49.4%75 KiB
https://connect.facebook.net/en_US/fbevents.js 3P103 KiB46%47 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/5314-33cb86aa.js 3P46 KiB59%27 KiB
https://connect.facebook.net/signals/config/1735692093320310?v=2.9.361&r=stable&domain=www.duolingo.com&hme=eec000113e1e9f56e9fc6cdeb39d59ad805f76a48c77cf3d5c028dcf3b38ee7c&ex_m=108%2C209%2C159%2C22%2C73%2C74%2C150%2C69%2C68%2C11%2C168%2C93%2C16%2C142%2C131%2C39%2C76%2C81%2C138%2C164%2C170%2C26%2C27%2C28%2C30%2C48%2C151%2C78%2C116%2C18%2C20%2C44%2C40%2C42%2C41%2C86%2C95%2C99%2C114%2C149%2C152%2C46%2C115%2C24%2C21%2C123%2C70%2C36%2C154%2C153%2C155%2C146%2C144%2C25%2C35%2C59%2C113%2C166%2C71%2C17%2C157%2C118%2C84%2C67%2C19%2C88%2C89%2C120%2C87%2C140%2C139%2C143%2C100%2C165%2C34%2C49%2C117%2C47%2C8%2C4%2C5%2C7%2C6%2C3%2C94%2C105%2C171%2C176%2C223%2C75%2C236%2C235%2C234%2C23%2C33%2C55%2C107%2C61%2C10%2C64%2C101%2C102%2C103%2C109%2C134%2C31%2C29%2C136%2C137%2C133%2C132%2C160%2C77%2C163%2C161%2C162%2C50%2C60%2C127%2C15%2C167%2C45%2C281%2C282%2C280%2C295%2C311%2C216%2C205%2C62%2C206%2C204%2C314%2C305%2C52%2C217%2C111%2C135%2C83%2C125%2C54%2C124%2C130%2C129%2C58%2C65%2C63%2C156%2C79%2C80%2C119%2C37%2C32%2C53%2C56%2C104%2C169%2C1%2C128%2C14%2C126%2C12%2C2%2C57%2C96%2C66%2C122%2C92%2C91%2C172%2C173%2C97%2C98%2C9%2C106%2C51%2C147%2C90%2C82%2C72%2C121%2C110%2C43%2C148%2C0%2C85%2C141%2C145%2C158%2C38%2C112%2C13%2C174 3P55 KiB47.9%26 KiB
https://www.google-analytics.com/analytics.js 3P21 KiB54.7%11 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/9078-363c7813.js 3P9 KiB74.3%7 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/7459-9ef3350b.js 3P7 KiB72.1%5 KiB

Network

157Requests
3444 KiBTransferred
35Scripts
99.4%3rd-party
10Long tasks
Script (35)
2154 KiB
Fetch (28)
699 KiB
Image (58)
355 KiB
Font (3)
165 KiB
Stylesheet (9)
42 KiB
Other (9)
16 KiB
XHR (11)
6 KiB
Document (2)
5 KiB
Manifest (1)
1 KiB
Ping (1)
1 KiB
Heaviest requests (30)
URLTypeStatusTransfer
https://www.gstatic.com/recaptcha/releases/A7KpaEASfhDcK0nXxgQEyyYv/recaptcha__en.jsScript200374 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/app-b99c4894.jsScript200307 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/9951-96351ecb.jsScript200238 KiB
https://www.googletagmanager.com/gtag/js?id=G-CSFDVCPQ4F&cx=c&gtm=4e67m0Script200183 KiB
https://www.googletagmanager.com/gtm.js?id=GTM-TX6Z97CScript200175 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/82f26795696242931a7b905b4918eb1e.jsonFetch200169 KiB
https://www.googletagmanager.com/gtag/js?id=AW-728842606&cx=c&gtm=4e67m0Script200151 KiB
https://www.googletagmanager.com/gtag/destination?id=AW-397119219&cx=c&gtm=4e67m0Script200144 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/e97b1cde32a58c629a0193eea36ddaab.jsonFetch200137 KiB
https://d35aaqx5ub95lt.cloudfront.net/images/splash/lottie/833a22b2834050d139f266a29899bb00.svgImage200122 KiB
https://cdn.cookielaw.org/scripttemplates/202404.1.0/otBannerSdk.jsScript200109 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/50bda50231c0bce1584e982cebfe8f33.jsonFetch200107 KiB
https://connect.facebook.net/en_US/fbevents.jsScript200103 KiB
https://accounts.google.com/gsi/clientScript20097 KiB
https://d35aaqx5ub95lt.cloudfront.net/vendor/f2331bbfd902cdf8971c4d3184a44283.woff2Font20075 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/9819-2006552c.jsScript20069 KiB
https://d35aaqx5ub95lt.cloudfront.net/vendor/3bbe299f41d8289a47d91773fee0cb6a.woff2Font20065 KiB
https://connect.facebook.net/signals/config/1735692093320310?v=2.9.361&r=stable&domain=www.duolingo.com&hme=eec000113e1e9f56e9fc6cdeb39d59ad805f76a48c77cf3d5c028dcf3b38ee7c&ex_m=108%2C209%2C159%2C22%2C73%2C74%2C150%2C69%2C68%2C11%2C168%2C93%2C16%2C142%2C131%2C39%2C76%2C81%2C138%2C164%2C170%2C26%2C27%2C28%2C30%2C48%2C151%2C78%2C116%2C18%2C20%2C44%2C40%2C42%2C41%2C86%2C95%2C99%2C114%2C149%2C152%2C46%2C115%2C24%2C21%2C123%2C70%2C36%2C154%2C153%2C155%2C146%2C144%2C25%2C35%2C59%2C113%2C166%2C71%2C17%2C157%2C118%2C84%2C67%2C19%2C88%2C89%2C120%2C87%2C140%2C139%2C143%2C100%2C165%2C34%2C49%2C117%2C47%2C8%2C4%2C5%2C7%2C6%2C3%2C94%2C105%2C171%2C176%2C223%2C75%2C236%2C235%2C234%2C23%2C33%2C55%2C107%2C61%2C10%2C64%2C101%2C102%2C103%2C109%2C134%2C31%2C29%2C136%2C137%2C133%2C132%2C160%2C77%2C163%2C161%2C162%2C50%2C60%2C127%2C15%2C167%2C45%2C281%2C282%2C280%2C295%2C311%2C216%2C205%2C62%2C206%2C204%2C314%2C305%2C52%2C217%2C111%2C135%2C83%2C125%2C54%2C124%2C130%2C129%2C58%2C65%2C63%2C156%2C79%2C80%2C119%2C37%2C32%2C53%2C56%2C104%2C169%2C1%2C128%2C14%2C126%2C12%2C2%2C57%2C96%2C66%2C122%2C92%2C91%2C172%2C173%2C97%2C98%2C9%2C106%2C51%2C147%2C90%2C82%2C72%2C121%2C110%2C43%2C148%2C0%2C85%2C141%2C145%2C158%2C38%2C112%2C13%2C174Script20055 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/904f242fe2ab5477e3b97928d3e1cb89.jsonFetch20053 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/71b01cd301b53ec9879f2d06eb85f5db.jsonFetch20052 KiB
https://d35aaqx5ub95lt.cloudfront.net/js/5314-33cb86aa.jsScript20046 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/c16e90b93e35750c893be4b58720cef2.jsonFetch20044 KiB
https://d35aaqx5ub95lt.cloudfront.net/lottie/splash/aea5aff1143a9410b81448245ad7c839.jsonFetch20041 KiB
https://d35aaqx5ub95lt.cloudfront.net/images/splash/lottie/23ab11cb1e1a9aff54facdf57833373d.svgImage20040 KiB
https://d35aaqx5ub95lt.cloudfront.net/images/splash/lottie/08ec8d0260c55c054e1b97bcbc96ea0f.svgImage20040 KiB
https://d35aaqx5ub95lt.cloudfront.net/images/splash/lottie/9d3c2c99dd19996319a372f79b2ed3c1.svgImage20035 KiB
https://cdn.cookielaw.org/consent/55a7f100-001e-4085-87ec-1a6d522f7d67/018f30d2-10c8-771e-8439-98a6c95838b2/en.jsonFetch20027 KiB
https://d35aaqx5ub95lt.cloudfront.net/vendor/68d22534874c554b0c9ebabea379fc60.woff2Font20025 KiB
https://www.google-analytics.com/analytics.jsScript20021 KiB
https://d35aaqx5ub95lt.cloudfront.net/images/splash/lottie/890eb76de9a395b182c1c28322721405.svgImage20017 KiB

Long tasks (>50 ms)

StartDuration
567 ms541 ms
2395 ms251 ms
3563 ms193 ms
3400 ms158 ms
3765 ms130 ms
2746 ms120 ms
1144 ms109 ms
4093 ms108 ms
2087 ms96 ms
2946 ms93 ms
Analyzing…
running mobile + desktop · ~30s