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Cookie reference · OneTrust

The OptanonConsent cookie

The OneTrust cookie that stores a visitor's choices for each cookie category, with a consent ID and timestamp.

OptanonConsent at a glance

Cookie name
OptanonConsent
Vendor
OneTrust
Category
Functional
Party
First-party
Typical duration
1 year by default
Set on
.<your-root-domain>
Value format
URL-encoded key=value pairs: isGpcEnabled, datestamp, version, groups, consentId, interactionCount and more
Name match
Exactly OptanonConsent

What the OptanonConsent cookie does

OptanonConsent is written by the OneTrust cookie banner. It records which cookie categories are on or off, when the choice was made, the script version, a consent ID that links to the consent record, and how many times the visitor has interacted with the banner.

The groups field holds category:0 or category:1 pairs, which is the quickest way to read a visitor's current choices in DevTools. OneTrust's default lifetime is 1 year, set by the Reconsent will occur after value in each geolocation rule. Production scripts write it to the root domain unless the site manages consent separately per subdomain.

What TagPipes observed

0.92%

of sites scanned set it (377 of 41,162)

365 days

median observed lifetime

TagPipes scanned 41,162 public websites between August 11, 2026 and September 13, 2026, loading up to three pages per site in a real browser as a first-time visitor. OptanonConsent was present on 377 of them.

It was set as a first-party cookie on 351 sites and as a third-party cookie on 26. A site can count in both. Where it was stored as a persistent cookie, the median lifetime we recorded was 365 days.

Often found alongside

Percentage of sites with OptanonConsent where the other cookie was also present.

Technologies detected on the same sites

  • OneTrust on 100% of them (1.2% of all sites scanned)
  • Google Fonts on 86% of them (78% of all sites scanned)
  • Google Analytics on 73% of them (55% of all sites scanned)
  • Google Tag Manager on 62% of them (30% of all sites scanned)
  • reCAPTCHA on 59% of them (32% of all sites scanned)

Aggregate figures across all sites scanned. Websites of TagPipes customers are excluded, no individual site is named, and cookie values are never read or stored. Snapshot dated September 13, 2026.

How to check for OptanonConsent on a website

  1. Open the site in Chrome, then open DevTools (F12, or Cmd+Option+I on a Mac).
  2. Go to the Application tab and expand Cookies in the left panel.
  3. Select each domain listed there and look for OptanonConsent. The Expires column shows when it will be deleted.
  4. If it is not there, reload the page. Many cookies are only set after a tag has loaded, and some only after a visitor has made a consent choice.

Other OneTrust cookies

Sources

Purpose, duration and value format checked against the vendor documentation above on . The figures under What TagPipes observed are TagPipes scan data from September 13, 2026, not values documented by the vendor. Vendors change their cookies, and sites can configure their own names and lifetimes. Browse all cookies.

Know every cookie your own site sets

TagPipes Pulse identifies the cookies dropped on your site and flags unclassified or miscategorized ones. Shield builds your cookie declaration from a real scan rather than a questionnaire.

See Pulse See Shield

TagPipes monitors, configures and reports. It does not determine legal compliance and does not provide legal advice. Output is informational and reflects observed state at the time of observation. Rawsoft's expertise is technology, not law; please confirm any regulatory interpretation with your own counsel.