User Agent Check
docAnalyze your User Agent string and UA-CH hints to identify browser engine, OS, and device signals. Spot mismatches in login flows and anti-bot challenges.
User Agent Check
Understand browser identity from both the legacy User-Agent string and modern User-Agent Client Hints, then diagnose compatibility breaks and risk-scoring mismatches with a repeatable workflow.
What this tool reports
The report parses classic User-Agent fields such as browser family, rendering engine, operating system, and device class.
Where supported, it also compares User-Agent Client Hints (UA-CH) like platform, architecture, and mobile flags so you can validate whether declared identity and observed environment align.
Why User-Agent still matters
Even with UA reduction in modern browsers, many sites and security gateways still use UA as a first-pass routing and policy signal.
UA can influence templates, feature toggles, anti-bot challenges, and fraud controls. A mismatch with TLS, locale, or network context often increases login friction.
How to read mismatch signals
Start by checking browser family, version, and platform against your real runtime. Desktop claims paired with mobile hints, or vice versa, are common spoofing artifacts.
If your goal is stable access, keep UA signals coherent with actual device and browser behavior instead of forcing custom strings globally.
UA vs UA-CH consistency
UA is a legacy free-form string; UA-CH provides structured fields. Many anti-abuse systems compare both and score consistency.
Changing only one side often leaves detectable seams, which can look like automation or misconfigured privacy tooling.
Common root causes in production
Frequent causes include proxy extensions rewriting headers, enterprise gateways normalizing request metadata, and anti-detect frameworks leaking contradictory identities.
After browser major updates, old UA parsing logic can also misclassify new versions until rules are updated.
Operational troubleshooting workflow
Step 1: capture a baseline UA and UA-CH in a clean browser profile. Step 2: run the same check in the problematic profile and diff the fields.
Step 3: change one variable at a time (extension, proxy, policy, or launch flag), retest, and record the delta. This single-variable loop avoids false conclusions.
Cross-check with related diagnostics
If issues involve login risk scoring, combine this page with TLS Fingerprint, IP Lookup, and DNS Leak Test.
A coherent identity across application, transport, and network layers is usually more important than maximizing any single privacy tweak.
Privacy and stability trade-offs
Frequent UA randomization can reduce static tracking in some cases, but high volatility can also trigger stricter bot defenses.
For most users, a mainstream and stable browser profile is the most practical balance between compatibility, privacy, and low-friction access.
Scope and limitations
UA analysis is a diagnostic input, not a final security verdict. Reliable decisions require context from behavior, network path, and business signals.
Compare results under controlled conditions. Cross-device and cross-network tests without controls can hide the real root cause.
Related Tools
Related Docs
- TLS Fingerprint — transport layer identity signals to cross-check with UA
- Browser Fingerprint — how browser signals combine beyond UA alone
Frequently Asked Questions
What does my User Agent string reveal?
Your User Agent string reveals your browser family, version, rendering engine, operating system, and sometimes device type. Even with modern browsers reducing UA detail, the remaining signals still carry enough information to classify your browser and influence how sites serve content, apply security policies, or trigger anti-bot checks.
What is User-Agent Client Hints (UA-CH)?
User-Agent Client Hints (UA-CH) are a modern replacement for the legacy User-Agent string. They provide structured, explicit headers for platform, architecture, mobile flags, and full browser version. Many anti-abuse systems now compare both UA and UA-CH fields to detect inconsistencies that may indicate spoofing or automation.
How do I check my User Agent string?
Use IPOK's User Agent Check tool to parse your current User-Agent string and UA-CH hints. Compare the reported fields against your actual browser version, OS, and device to identify any mismatch. Inconsistencies between declared and observed identity often increase login friction or trigger additional verification steps.
Why does my User Agent mismatch cause login issues?
User Agent mismatches cause login issues when security systems detect inconsistency between UA, TLS fingerprint, locale, or network path. For example, a mobile UA paired with a desktop TLS fingerprint may trigger risk controls. Proxy extensions, enterprise gateways, or anti-detect browsers that rewrite only one side of these signals often leave detectable seams.