Prebid User ID Inspector
Inspect Prebid `userId` and `userSync` configuration to see which identity modules appear active, what storage types they use, whether consent markers are visible, and whether auction delay settings look aggressive. This gives teams a real first-pass identity and sync review that is specific to header bidding rather than generic privacy tooling.
Review Prebid identity modules and sync settings before they quietly complicate the auction.
What you can do here
- Review a new SharedID, UID2, or ID5 rollout.
- Explain why a page feels heavier after identity changes.
- Check whether userSync settings line up with team expectations.
Before you start
- Paste a real userId or userSync config block.
About Prebid User ID Inspector
The Prebid User ID Inspector focuses on `userId`, `userSync`, storage, consent, and auction-delay settings so teams can understand how identity configuration may affect bidder readiness and page complexity.
Use it when identity modules were added recently, when sync behavior looks unclear, or when teams need a tighter first-pass than a generic cookie scan.
Best uses for Prebid User ID Inspector
- Review a new SharedID, UID2, or ID5 rollout.
- Explain why a page feels heavier after identity changes.
- Check whether userSync settings line up with team expectations.
How to use Prebid User ID Inspector
- Paste a `userId` or `userSync` config snippet.
- Inspect ID modules, storage, sync flags, and auction delay.
- Use the warnings to decide what to validate live.
What to paste in
- Paste a real userId or userSync config block.
What you should see
- Detected ID modules, storage types, sync markers, and warnings.
Example checks
These are simple checks you can run when you want a real sample and a clear result to compare against.
Paste a real userId or userSync config block.
Why run it: Review a new SharedID, UID2, or ID5 rollout.
What to look for: Detected ID modules, storage types, sync markers, and warnings.
Identity Modules Change Header Bidding Behavior More Than Many Teams Realize
Why identity settings deserve first-pass visibility
A page can look like a straightforward header bidding implementation while quietly carrying significant identity complexity. SharedID, UID2, ID5, and other modules influence storage, consent dependencies, sync behavior, and sometimes the real start of the auction. When teams only look at bidder timings, they miss the fact that the auction path may already be heavier before the first bidder request is even sent.
This is why identity config deserves its own inspection step. Not every debugging task needs a full privacy or network audit right away. Often teams simply need to know which user ID modules appear configured, whether user sync is enabled, what storage types are referenced, and whether consent markers are visible at all. That first-pass answer shortens the path to deeper validation.
Keeping this tool in the header bidding section also matters conceptually. Identity modules are often discussed as privacy-only concerns, but operationally they are auction concerns too. They affect bidder readiness and page complexity, not just compliance reviews.
What a practical identity review should show
The useful starting points are module detection, storage hints, sync controls, consent markers, and auction delay. If a page appears to run multiple ID modules with no visible consent management and a high auction delay, that is already an actionable clue. The exact runtime behavior still needs validation, but the likely areas of risk are visible sooner.
This is especially useful after changes. Identity rollouts often happen incrementally and then get forgotten. A team may add one module to improve match rates, then months later add another, then tune sync settings without re-evaluating the whole setup. Over time the configuration becomes operationally significant even if no single change looked dramatic in isolation.
A compact identity inspector gives teams a way to review the current state without turning every debugging task into a full browser forensic exercise. That is a practical win for both engineering and ad ops.
How identity review supports better debugging
Once the identity shape is visible, teams can decide what to do next. If multiple ID modules are configured with visible delay, they may need a runtime timing review. If sync settings look absent or disabled, the question may shift toward why certain bidders are not behaving as expected. If consent markers are missing, the issue may belong to implementation quality more than bidder performance.
This layered workflow is what makes the tool useful in practice. It does not claim to prove everything about identity behavior. It gives teams a narrower, more accurate starting point than generic page inspection alone.
From an SEO perspective, this is also the kind of specific debugging intent a niche site should pursue. Someone searching for Prebid user ID debugging is usually much closer to a real problem than someone searching for header bidding broadly.
Troubleshooting
What to look for
- Detected ID modules, storage types, sync markers, and warnings.
Common issues
- Runtime identity behavior can still differ if scripts fail or consent is delayed.
- A page may contain additional identity logic outside the pasted config.
Best practices
- Paste raw input so the tool can apply formatting consistently.
- If output looks wrong, validate the input for missing commas or tags.
- Use the example buttons above to sanity-check formatting and behavior.
Related tools
More tools in the header bidding category.
- Prebid Timeout Risk Analyzer - Diagnose Prebid auction timeout risk from real config snippets, adUnits, and optional bidder timing notes. Instead of only guessing from fetched HTML, the tool inspects timeout settings, auction pressure, identity delay markers, and pasted bidder outcomes so teams get a more actionable first-pass readout of why bids may be missing the auction.
- Prebid Config Inspector - Inspect a Prebid `pbjs.setConfig` snippet and surface the auction settings that actually shape runtime behavior: bidder timeout, timeout buffer, consent modules, user sync, floors, S2S, and more. This tool is built for engineers and ad-ops teams who need a fast readout of whether a configuration is sane before they open devtools or live auction logs. Paste a real config block and get concrete findings instead of guessing which modules are active.
- Prebid Ad Unit Inspector - Parse a real `adUnits` snippet and break it down into ad-unit codes, media types, sizes, bidder counts, and duplicate patterns. This is useful when a page looks overloaded, when bidders are attached to the wrong unit, or when teams need to understand the auction shape quickly before debugging runtime issues. It focuses on the ad-unit layer instead of the broader page shell.
- Schain Validator - Validate a Prebid or OpenRTB supply chain object by checking version, complete flag, node count, and missing `asi` / `sid` / `hp` fields. This is useful during supply-path reviews, reseller onboarding, or anytime a team needs to explain how a supply chain should look before it reaches bidders.
Related reading
More specific pages for the exact jobs this tool supports.
Inspect Prebid Identity Config Before Consent Testing
A focused identity workflow for Prebid setups that recently changed.
Review User ID Modules After a SharedID Rollout
A narrow rollout-review page for identity module changes.
Check Prebid Auction Delay From User ID Config
An auction-delay workflow for ID-heavy Prebid pages.
Inspect Prebid Storage Types During Identity QA
A storage-focused identity workflow for implementation QA.
Check UserSync Flags After a CMP Update
A post-CMP identity workflow for sync and delay settings.
Validate User ID Submodule Order Before QA
A module-order workflow for Prebid identity reviews.
Review Prebid Config Before a Launch
A first-pass config workflow for rollout reviews and implementation QA.
Find Mismatched Prebid Timeout and S2S Settings
A config-specific workflow for timeout mismatch before it becomes an auction issue.
Frequently asked questions
Is it free to use?
Yes. Core tools are free and accessible without signup.
Does it upload my data?
This tool runs locally in your browser. Data you paste or files you upload stay on your device and are not uploaded.
What if I spot a bug?
Please reach out via the Contact page with a reproduction example.
Does it prove IDs are syncing live?
No. It inspects config, not runtime network traffic.
Why not just use browser devtools?
Devtools are still necessary, but this tool tells you what the page appears to be configured to do before you open a full trace.
Can it read multiple ID modules?
Yes. It is built to detect common Prebid identity module names and storage settings.
Helpful links
Standards & references
Official specs that inform how this tool interprets data.