What does duolingo.com track?
Before any consent, duolingo.com loaded 1 tracking company and set 1 advertising or analytics cookie.
That's fewer tracking companies than most sites we scanned: 75% of the 2,450 sites we checked loaded more.
Scanned October 2, 2026 from Germany, loading www.duolingo.com once and clicking nothing. How we scan
- Tracking companies
- 1
- Tracking cookies
- 1
- Third-party hosts
- 8
- Cookies in total
- 10
Consent banner
The page loaded OneTrust, a consent management platform. Everything below was recorded before anyone answered it. 1 tracking company still loaded while it was unanswered.
Companies contacted before consent
1 of the 4 companies it contacted before consent were analytics companies.
- Google Analytics1 requestAnalytics
www.googletagmanager.com
Other third parties (content delivery, consent, functional, unclassified)
- OneTrust7 requestsConsent banner
cdn.cookielaw.org, geolocation.onetrust.com
- Google11 requestsFunctional
www.gstatic.com, www.recaptcha.net, accounts.google.com, fonts.gstatic.com
- Amazon Web Services96 requestsContent delivery
d35aaqx5ub95lt.cloudfront.net
Cookies set before consent
The longest-lived tracking cookie it set was lu, lasting about 12 months.
| Cookie | Purpose | Set by | Lasts |
|---|---|---|---|
| lu | Advertising | duolingo.com | 12 months |
| initial_referrer | Unclassified | duolingo.com | 12 months |
| logged_out_uuid | Unclassified | duolingo.com | 12 months |
| lp | Unclassified | duolingo.com | 12 months |
| lr | Unclassified | duolingo.com | 12 months |
| tsl | Unclassified | duolingo.com | 12 months |
| wuuid | Unclassified | www.duolingo.com | Session |
| g_state | Functional | www.duolingo.com | 6 months |
| lang | Functional | duolingo.com | 12 months |
| OptanonConsent | Functional | duolingo.com | 6 months |
The page also wrote 1 key to local storage, which works like a cookie but isn't sent with requests.
Understanding this page
- How to see which cookies and trackers a website loads
A hands-on walkthrough for checking what a site sets before you've clicked anything, using Chrome and Firefox's built-in tools, plus how CookieTosser automates the same check every month.
- What counts as valid cookie consent in the EU
The rules that actually govern cookie banners — the ePrivacy Directive, the GDPR consent standard, the Planet49 ruling, the strictly-necessary exemption, and what "reject" has to offer compared with "accept.
- Consent management platforms explained
What a CMP banner is actually doing behind the scenes, how the IAB's TCF standard and Google's Consent Mode v2 fit in, and why a banner being present is no guarantee that nothing loads before you answer it.