Google Analytics Inspector

Debug GA4 events with Client/sGTM split view, parameter validation, POST body parsing, and item inspection

GA4 Inspector is a developer tool for debugging Google Analytics 4 implementations. It intercepts every GA4 network request in real time and displays it in a structured, readable format in Chrome's side panel — replacing the manual process of digging through DevTools network requests and decoding URL parameters by hand. If you work with GA4 — whether you're a developer implementing tracking, an analyst verifying data quality, or a QA tester checking an e-commerce funnel — this extension shows you exactly what data is being sent to Google Analytics, flags what's wrong, and generates a report you can hand to a developer to fix. 𝗖𝗟𝗜𝗘𝗡𝗧-𝗦𝗜𝗗𝗘 𝘃𝘀 𝘀𝗚𝗧𝗠 𝗦𝗣𝗟𝗜𝗧 𝗩𝗜𝗘𝗪 GA4 Inspector automatically detects whether each event is being sent directly to Google Analytics (client-side) or routed through a server-side Google Tag Manager container (sGTM). Three tabs at the top of the panel let you filter between All, Client-Side, or sGTM events. Each event card is clearly tagged so you can verify both data pathways independently. 𝗘-𝗖𝗢𝗠𝗠𝗘𝗥𝗖𝗘 𝗜𝗧𝗘𝗠 𝗣𝗔𝗥𝗦𝗜𝗡𝗚 GA4 encodes product data as compressed pr strings (pr1, pr2, etc.) that are difficult to read in raw form. The extension decodes every item into a structured card showing item name, ID, price, quantity, brand, category, variant, and all custom dimensions and metrics. Custom dimensions are displayed in a clearly labelled section, and custom metrics are shown separately — so you can verify that product data is being structured correctly rather than serialised into a single string parameter. 𝗕𝗔𝗧𝗖𝗛𝗘𝗗 𝗘𝗩𝗘𝗡𝗧 𝗦𝗣𝗟𝗜𝗧𝗧𝗜𝗡𝗚 GA4 frequently bundles multiple events into a single HTTP request — shared parameters in the URL, per-event parameters in the POST body. This means you won't find every event by searching Chrome DevTools by name. GA4 Inspector splits batched requests into individual event cards, each with a batch indicator showing its position (e.g. 1/2, 2/2). Every event is fully decoded regardless of how it was transported. 𝗔𝗨𝗧𝗢𝗠𝗔𝗧𝗜𝗖 𝗩𝗔𝗟𝗜𝗗𝗔𝗧𝗜𝗢𝗡 Every event is validated against the GA4 specification in real time. Issues are categorised by severity: CRITICAL — Data is being lost or broken. Events with critical errors will not report correctly. WARNING — Data quality is reduced. Missing recommended parameters or potential misconfigurations. INFO — Informational notices worth reviewing, such as consent mode status. Validation checks include: Event name rules: 40-character limit, must start with a letter, no spaces, no reserved names or prefixes Parameter limits: maximum 25 per event, 40-character names, value length limits with appropriate thresholds for URL-type parameters User property limits: maximum 25 properties, 24-character names, 36-character values E-commerce validation: required and recommended parameters per event type, item_id OR item_name present, currency format, value data types Purchase-specific checks: zero-value detection, items total vs reported value comparison, duplicate transaction_id detection across the entire session Case-sensitivity: catches "Purchase" instead of "purchase", which GA4 treats as a completely different custom event Payload size warnings when requests exceed the 8,192 byte URL limit Missing client_id detection (events cannot be attributed to any user) Missing session_id on sGTM events (the primary cause of "(not set) / (not set)" in traffic source reports) 𝗗𝗘𝗕𝗨𝗚 𝗟𝗢𝗚 & 𝗗𝗢𝗪𝗡𝗟𝗢𝗔𝗗𝗔𝗕𝗟𝗘 𝗥𝗘𝗣𝗢𝗥𝗧𝗦 The debug log accumulates every error, warning, and info notice from the entire browsing session into a structured report. Each issue includes a clear English title, the affected parameter, what was detected, a "Why this matters" explanation of the real-world impact, and a "How to fix" resolution guide with concrete steps. The report can be copied to clipboard (for pasting into Slack, email, or Jira) or downloaded as a .txt file. Issues are deduplicated by type — if the same problem occurs on 15 events, it appears once with sample occurrences listed underneath. The report includes a session tracking section at the bottom with measurement IDs, client IDs, session IDs, consent state, and any UTM or gclid campaign attribution detected during the session. 𝗠𝗘𝗔𝗦𝗨𝗥𝗘𝗠𝗘𝗡𝗧 𝗜𝗗 𝗖𝗢𝗟𝗢𝗨𝗥 𝗖𝗢𝗗𝗜𝗡𝗚 Each unique Measurement ID is automatically assigned a distinct colour from a palette of eight. The ID appears as a coloured pill on every event card. If a site sends data to multiple GA4 properties, you can scan the event list and see the colour pattern without reading the ID strings. 𝗔𝗗𝗗𝗜𝗧𝗜𝗢𝗡𝗔𝗟 𝗙𝗘𝗔𝗧𝗨𝗥𝗘𝗦 Session start detection — events with a session start signal show a green badge on the card header Consent Mode display — colour-coded granted/denied/default badges for ad_storage, analytics_storage, ad_user_data, and ad_personalization BigQuery schema preview — see how each event will appear in the BigQuery export, including event_params and unnested items Event parameter grouping — parameters are grouped into Transaction Parameters, Custom Dimensions (ep.), and Custom Metrics (epn.) with type badges Duplicate event detection — flags events that fire multiple times within 500ms Filters — filter by stream type (Client/sGTM), event category (All/Ecom/Conv), issues only, measurement ID, or event name Export — download all captured events as JSON for offline analysis Built-in guide — full documentation accessible from within the extension 𝗣𝗥𝗜𝗩𝗔𝗖𝗬 GA4 Inspector operates entirely within your browser. It does not transmit any data externally, does not require an account, and does not modify any network requests. It passively reads GA4 collect requests that your browser is already sending and displays them locally in the side panel.