Tag Lens 360 - Tag Debugger & Inspector

Tag Lens 360 is a free, professional tool to debug and validate marketing tags, pixels, cookies, and data layers on any website.

Tag Lens 360 helps analysts, tag managers, developers, and QA teams verify that marketing tags, analytics pixels, cookies, and data layers are working correctly on their websites. Use it to see which tracking requests are firing on a page, read the exact values being sent, validate your implementation against your own rules, and inspect cookies and data layers without opening the browser console. Single purpose Debugging and validating web analytics and marketing tag implementations on the pages you visit. Tag capture Tag Lens 360 displays every tag request that fires on the current page, including the full request URL, decoded query and POST parameters, HTTP status, event type, and account identifiers. Parameters are decoded and shown with human-readable labels so you can understand what each value means without looking up documentation. Page view and link tracking requests are clearly distinguished at the tag header level. Any tag can be expanded to see all captured variables, and the details can be copied as JSON for sharing with your team. Data layer inspection Read values directly from the data layer objects on the page, so you don't need to open the browser console. Common structures are supported out of the box including dataLayer (GTM), digitalData (W3C / CEDDL), adobeDataLayer, utag_data (Tealium), analytics (Segment-style), and Adobe AppMeasurement (s). You can also register your own custom object names. Values are shown in a readable key-and-value format and update in place without flickering. Validation Create your own rule sets to check whether specific variables meet expected values. Rules support equals, contains, starts with, regex match, and existence checks. Results display in collapsible accordions with pass/fail counts per rule set, and show the actual captured value alongside every result. Rule sets can be scoped to specific page URLs using contains, starts with, or regex matching, so you can create different rules for different page types. Export and import rule sets as JSON to share with your team or back up your configuration. Export validation results as a CSV report for documentation and sign-off. Cookie inspection View every cookie available on the current page including name, value, domain, expiry, SameSite, Secure, and HttpOnly flags. Export the full list as CSV. Request filtering for testing Optionally filter specific URL patterns while you debug. This feature is intended for QA scenarios, for example testing what a page looks like when a particular tag does not fire. Filtering is off by default, rules are user-defined, and everything can be toggled on or off at any time. It uses Chrome's built-in declarativeNetRequest. Session tracking Turn on Preserve Log to keep captured tags as you navigate between pages. Each page is separated by a navigation divider showing URL, timestamp, and tag count. The current page is highlighted and pinned to the top of the scroll area so you can always see which page you are inspecting. Data layer values are captured separately for each page. You can remove tags from a single page without clearing the rest of your session. Export Download all captured tags as a CSV, export details from a single tag, export the cookie list as a CSV, or export validation results as a CSV report. Privacy Tag Lens 360 runs entirely in your browser. It does not use accounts, does not contact external servers, and does not send any data from the pages you visit to anyone. Captured tags, validation rules, and settings are kept in Chrome's local extension storage on your own machine. Permissions used Each permission this extension requests is used only for the feature described. * webRequest - capture outgoing tag requests on the active tab * declarativeNetRequest / declarativeNetRequestFeedback - apply user-defined request-filtering rules and report hits * storage - save your validation rules, filtering rules, and UI preferences locally * cookies - read cookies for the active tab * activeTab - ensure the extension only accesses the tab the user is actively viewing * tabs - detect page navigation for session tracking * host_permissions: <all_urls> - the extension must be able to read tag requests on whichever site the user is debugging DEVTOOLS PANEL - Fully responsive: adapts to bottom-docked, side-docked, and detached windows at any size.