Identifier diagnostics
An identifier may be present at click time and disappear before browser storage, the request, server mapping, or the destination platform. Diagnosis becomes reliable when each boundary is checked separately.
Seeing an identifier at one stage does not prove that it reached the next. A correct URL may be followed by denied consent, missing storage, a destructive redirect, an incomplete request, or incorrect server mapping.
This page starts from the observed symptom and traces the chain in an explicit order. Technical checks, affected artifacts, and sources come from the atlas shared registry.
Stage 1 / 7
Confirm the first observable surface before any page-side processing.
Observed symptom
Next inspection
Capture the URL before any client-side redirect, then check auto-tagging, the final URL, and applicable campaign parameters.
Affected artifacts
gclidURL parameterAn identifier may be present at click time and disappear before browser storage, the request, server mapping, or the destination platform. Diagnosis becomes reliable when each boundary is checked separately.
Tracking knowledge base
A tracking identifier may arrive in a URL, be retained in a cookie, and then be forwarded in a request or server payload. This atlas separates each surface for Google, Meta, and TikTok.
Read the pageTracking knowledge base
gbraidwbraidURL parameterAtlas family · Google
Google Ads click identifiers— Open the family in the atlasStage 2 / 7
Observe the state actually applied when the tag or storage is evaluated.
Observed symptom
Next inspection
Inspect analytics_storage when the tag fires and any later update before expecting a cookie.
Affected artifacts
_gaFirst-party cookieOfficial evidence
Atlas family · Google
Google Analytics client identifier— Open the family in the atlasStage 3 / 7
Separate creation, reading, domain, and storage surface.
Observed symptom
Next inspection
Check consent, the configured cookie name, the domain, and whether the GA4 tag fired.
Affected artifacts
_gaFirst-party cookieOfficial evidence
Atlas family · Google
Google Analytics client identifier— Open the family in the atlasObserved symptom
Next inspection
Compare the stream ID, configured prefix, and cookies created after consent.
Affected artifacts
_ga_<container-id>First-party cookieObserved symptom
Next inspection
Compare their domain, first-party or third-party context, and attributes before drawing a conclusion.
Affected artifacts
_ttpFirst-party cookie_ttpThird-party cookieuser.ttpServer payload fieldOfficial evidence
Observed symptom
Next inspection
Check the loaded Pixel code, consent, and whether the Pixel actually fired.
Affected artifacts
ttcsidFirst-party cookiettcsid_<pixel-code>First-party cookieOfficial evidence
Atlas family · TikTok
TikTok session identifiersObserved symptom
Next inspection
First confirm that Pangle is part of the tested configuration; its absence may be expected.
Affected artifacts
_pangleThird-party cookieOfficial evidence
Atlas family · TikTok
TikTok Pangle cookie— Open the family in the atlasStage 4 / 7
Check that the value survives every navigation and URL rewrite.
Observed symptom
Next inspection
Inspect redirects, link decoration, the domain list, and the delay between generation and reading.
Affected artifacts
_ga / _gcl_*First-party cookie_glURL parameter_ga / _gcl_*First-party cookieOfficial evidence
Atlas family · Google
Google linker parameter— Open the family in the atlasStage 5 / 7
Inspect the fields actually sent by the browser or tag.
Observed symptom
Next inspection
Compare the value available in the browser with the field sent in the event request; do not infer forwarding from cookie presence alone.
Affected artifacts
ttclidURL parameterttclidFirst-party cookieuser.ttclidServer payload fieldOfficial evidence
Atlas family · TikTok
TikTok click identifier— Open the family in the atlasStage 6 / 7
Compare the received value with the field built for the destination API.
Observed symptom
Next inspection
Check URL capture, _fbc construction, and mapping to user_data.fbc separately.
Affected artifacts
fbclidURL parameter_fbcFirst-party cookiefbcServer payload fieldOfficial evidence
Atlas family · Meta
Meta click identifier— Open the family in the atlasObserved symptom
Next inspection
Check permitted cookie reading and exact mapping, without sending _fbp as the API field name.
Affected artifacts
_fbpFirst-party cookiefbpServer payload fieldStage 7 / 7
Confirm receipt and use of the signal instead of inferring them from earlier stages.
Observed symptom
Next inspection
Compare the emitted conversion request with the diagnostics available in Google Ads, then confirm that the expected identifier was received before analyzing attribution.
Affected artifacts
gclidURL parametergbraidURL parameterwbraidURL parameter_gcl_*First-party cookie_gcl_lsLocal storage_gcl_auFirst-party cookieOfficial evidence
Atlas family · Google
Google Ads click identifiers— Open the family in the atlasA broken stack does not always look broken in the interface. The early signals are often CRM gaps, duplicate conversions, unstable attribution, or platforms that “improve” while the business does not.
Atlas family · Google
Google Analytics session state— Open the family in the atlasAtlas family · TikTok
TikTok browser identifier— Open the family in the atlasAtlas family · Meta
Meta browser identifier— Open the family in the atlas