DPE-2026-0004

Maximum cookie lifetime

An identifier cookie is set for the maximum lifetime a browser accepts, before the question is answered.

In het NederlandsMaximale bewaartermijnWat vraag ik hierover, en hoe herken ik een ontwijkend antwoord?
Retention web status active

What it is

At page load, before any consent interaction, a cookie is placed with a lifetime at or near the ceiling the browser permits, currently 399 days in Chromium-based browsers.

Why it is a separate entry

The visitor is recognisable for over a year on the basis of a decision they were never given. Storage limitation requires a term tied to the purpose, not to the technical maximum.

How it arises

Not to be confused with

If the cookie is set only after consent, this is a retention question and not this entry. The pre-consent placement is what makes it a fault here.

How to establish it

A Set-Cookie with max-age at or above 34128000 seconds (399 days), or an equivalent Expires, issued before the consent event.

method network-with-identifierQoD 95

Requirements on the measurement

What would refute it

Where this plugs into existing processes

The one question that surfaces itWhat is the longest-lived cookie you set before anyone has chosen anything?
In a DPIA, verify this

Verify the actual lifetime of identifiers set before consent, rather than the retention table in the document.

As a procurement clause

No identifier is stored with a lifetime beyond what the stated purpose requires, and none before consent.

With a complaint, hand over

The Set-Cookie headers from the pre-consent capture, with lifetimes.

Reproduction

Third parties that can confirm it: urlscan.io, webbkoll

Legal framing

Case law

Objections, and the answer

“399 days is the industry default.”

A default is not a purpose. Storage limitation asks what term the purpose requires, and the browser ceiling is not an answer to that question.

What this does not establish

Related

How to cite this entry

In text
DPE-2026-0004 (Maximum cookie lifetime)
URL
https://totaledigitalewaarborging.nl/register/DPE-2026-0004
Machine
https://totaledigitalewaarborging.nl/register/DPE-2026-0004/index.json
Full
DPE Catalogue. DPE-2026-0004: Maximum cookie lifetime. Schema 2.0, entry status active. Retrieved from https://totaledigitalewaarborging.nl/register/DPE-2026-0004
Measurement
When you publish a finding, cite the method version alongside the entry: “DPE-2026-0004, established under DPE Measurement Method 1.0”

Identifiers are permanent and are never reused. An entry that is deprecated keeps its number and its address, with the reason attached, because references to it exist elsewhere.