Field Backpack

$89

A clean, well-built product for the demo. This page logs its own pageview and checks for an embedded widget independently.

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uid cookie lifetime

document.cookie cannot report expiry, so the page cannot read a cookie's remaining life. What it can show is how long one has already survived. If Safari caps the cookie, the value disappears, a new uid is minted, and age resets to 0m — that reset is the result you are looking for.

Server asked for

No uid Set-Cookie seen from the tracker yet. With UseServersideCookie off there is no _smtruid — the script writes _mtruid itself, which Safari caps at 7 days regardless.

Browser actually kept

No uid cookie on this request yet — reload once.

ITP probe — is this browser capping script-written cookies?

No probes yet — reload once to start the clock.

tb_probe_srv is written by this server via Set-Cookie; tb_probe_js by document.cookie. Identical attributes, identical 13-month expiry, written once and never refreshed — the only difference is who wrote them. Their ages are in the table above. Safari cannot report a cookie's expiry, so divergence between these two is the measurement.