How they behave
A custom purpose uses a stable key prefixed with `custom_`, which is what makes the decision durable: the label can be rewritten and translated without orphaning the decisions already recorded against it. Its stored decision is independent: a visitor who grants `custom_personalisation` has granted nothing in functional, analytics, marketing or media.
Scripts attached to a custom purpose are gated by it alone. The documentation’s verification advice is explicit about proving this, because a custom purpose that quietly unlocks marketing is worse than not having one.
When to reach for one
- A processing activity a visitor should be able to refuse separately from advertising
- A partner integration that does not sit naturally in any default category
- A jurisdiction whose separate-consent expectations push towards finer granularity, such as Korea
- An internal experiment you want to be able to switch off per visitor and prove you did
Granularity has a cost
Every extra purpose adds another control to the detailed view. Preserve a prominent, comparably easy route to refuse all optional purposes; purpose granularity should improve understanding, not manufacture friction.
Common questions
Can a custom purpose be removed later?
Yes. Existing published categories keep working and can be removed, and the decisions recorded against them stay readable. Removal is a privacy-relevant change and produces a new configuration version.
Do custom purposes appear in the browser API?
Yes. They are part of the consent state the runtime exposes, so a script registered against `custom_research` is gated on exactly that key.
Sources and verification
Verified on . Product-behaviour statements were checked against the current implementation and tests. The links below are the verification basis recorded for this article. They support the stated facts, not a legal conclusion for every site or configuration; recheck changing vendor behaviour before relying on it in production.
- Regulation (EU) 2016/679 (GDPR)
Legislation
Checked
- StrongPrivacy documentation
Product documentation
Checked
See what your own site is loading
A browser scan reports the requests and storage it observed during the sampled journey. Use configured workspace scans to compare the states and pages that matter to your implementation.