android-api-cf.duolingo.com
Duolingo - The world’s most popular way to learn
Last scanned Jul 23, 2026, 12:53 PM
Overall score
Great
Summary
Free, fun, and effective courses in languages and more. This website uses Google Analytics hosted on AWS behind CloudFront CDN. SEO is excellent (95/100) and accessibility is fair (70/100). Security scores good (75/100) and performance good (85/100). Top issue: Multiple H1 headings found.
Duolingo
Free, fun, and effective courses in languages and more. Learn with quick, science-based lessons personalized to you.
- United States
- Hosted on AWS
Top issues to fix
5 issues found · 3 high priority
Missing Strict-Transport-Security header
SecurityAdd HSTS so browsers always use HTTPS — this closes the protocol-downgrade attack window.
Missing Content-Security-Policy header
SecurityAdd a CSP to control which sources can run scripts — the strongest single defense against XSS.
Over half of images are missing alt text
AccessibilityAdd alt attributes to images — screen readers depend on them, and they help image SEO.
Missing X-Content-Type-Options header
SecurityAdd X-Content-Type-Options: nosniff to stop MIME-sniffing attacks.
Multiple H1 headings found
SEOKeep a single H1 per page and demote the others to H2/H3.
SEO
1 issue(s) found
Performance
256 ms
Security
HTTPS & header checks
Accessibility
1 issue(s) found
Organization
Company details published in this site's own structured data.
Contact
Email, phone, and address published on this site's own pages.
Meta tags
- Title
- Duolingo - The world’s most popular way to learn
- Description
- Free, fun, and effective courses in languages and more. Learn with quick, science-based lessons personalized to you.
- Canonical
- https://android-api-cf.duolingo.com/
- Language
- en
- Charset
- utf-8
- Viewport
- width=device-width,initial-scale=1,user-scalable=no
- Robots meta
- NOODP
- Manifest
- https://android-api-cf.duolingo.com/manifest.json
Technologies
Detected frameworks, languages, and tools.
Hosting & CDN
- Hosting provider
- AWS
- CDN provider
- CloudFront
- IP address
- 18.66.41.76
- ASN
- AS16509 (AMAZON-02 - Amazon.com, Inc., US)
DNS records
| Type | Value |
|---|---|
| A |
|
| AAAA | — |
| MX | — |
| TXT | — |
| NS | — |
| CAA | — |
| CNAME | — |
| IPv6 support | No |
TLS / SSL certificate
- Version
- TLS 1.3
- Issuer
- Amazon
- Subject
- *.duolingo.com
- Valid from
- Nov 25, 2025
- Valid to
- Dec 24, 2026
- Days until expiry
- 154
- SAN domains
- *.duolingo.com
Security headers
- Strict-Transport-SecurityMissing
- Content-Security-PolicyMissing
- X-Frame-OptionsEnabled
- X-Content-Type-OptionsMissing
- Referrer-PolicyMissing
- Permissions-PolicyMissing
Compression: gzip · 0 cookie(s) observed
Content & assets
Headings
H1 3 · H2 5 · H3 0
Links
53 internal · 56 external · 0 broken
Images
52 total · 42 missing alt
Scripts / Styles
30 scripts · 9 stylesheets
JS / CSS size
1.5 MB · 81.6 KB
Page size
11.0 KB
Robots.txt & Sitemap
- robots.txt
- Found
- Disallow rules
- 25
- sitemap.xml
- Found
- URLs in sitemap
- -1
SEO issues
- Multiple H1 headings found
Accessibility issues
- Over half of images are missing alt text
Careers
This company has an active careers page, but individual openings weren't reliably parsed from it — visit the page above for current listings.
Scan details
- Requested URL
- https://android-api-cf.duolingo.com
- Final URL
- https://android-api-cf.duolingo.com
- HTTP status
- 200
- HTTP version
- HTTP/2
- Response time
- 256 ms
- HTML size
- 11.0 KB
- Redirect chain
- https://android-api-cf.duolingo.com
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Frequently asked questions
- What technology does android-api-cf.duolingo.com use?
- android-api-cf.duolingo.com is built with Google Analytics, Google Ads, Meta Pixel.
- Is android-api-cf.duolingo.com secure (HTTPS)?
- Yes. android-api-cf.duolingo.com uses TLS 1.3 with a certificate issued by Amazon, valid until Dec 24, 2026.
- Who hosts android-api-cf.duolingo.com?
- android-api-cf.duolingo.com is hosted on AWS, behind CloudFront CDN.
- What is android-api-cf.duolingo.com's SEO score?
- android-api-cf.duolingo.com scored 95/100 for SEO in the latest analysis (excellent).
- What is android-api-cf.duolingo.com's overall website score?
- android-api-cf.duolingo.com has an overall SiteGraph score of 83/100, combining SEO, performance, security, and accessibility.
- What company operates android-api-cf.duolingo.com?
- android-api-cf.duolingo.com is operated by Duolingo. Free, fun, and effective courses in languages and more. Learn with quick, science-based lessons personalized to you.
- Is android-api-cf.duolingo.com hiring?
- android-api-cf.duolingo.com has a careers page; check it directly for current openings.
OpenGraph & Twitter Card
OpenGraph
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