{"slug": "new-in-devtools-october-2026", "title": "New in DevTools - October 2026", "summary": "Chrome 153 and Chrome 154 shipped to stable, bringing DevTools updates that include new security controls, performance tuning and memory analysis for coding agents through the Chrome DevTools MCP server. The release adds an Agent Plugins 1.0 package, JavaScript execution controls via --no-javascript-evaluation, on-demand source maps, configurable file system roots with --allow-unrestricted-paths enabled by default, heap snapshot inspection with query_heapsnapshot, PWA automation tools, and optional stack traces in list_console_messages. The Application panel gains ad script tracking with four experimental CrUX ad metrics (viewport ad density, viewport ad count, total CPU usage by ads, total network usage by ads), while Performance adds full soft navigation support in Insights, CPU performance tier overrides over CDP via Emulation.setCPUPerformanceOverride, and extension track search in the flame chart.", "body_md": "Published: September 22, 2026\n\nChrome 153 and Chrome 154 rolled out to stable over the past month, delivering a wave of developer improvements ready for your everyday workflow. This edition highlights fine-grained JavaScript execution controls in DevTools for agents, ad script tracking in the Application panel, full soft navigation support and CPU performance tier overrides in Performance, support for inactive styles and keyboard-accessible adorners in Elements, source inspection and performance trace recording in AI assistance, and modernized device presets in Device Mode.\n\n## DevTools for agents\n\nThe Chrome DevTools MCP server introduces new security controls, performance tuning, and memory analysis capabilities for coding agents:\n\n- **Agent Plugins 1.0 package** : Added support for the Agent Plugins 1.0\npackage, allowing agents to load and execute modular plugin extensions.\n- **JavaScript execution controls** : Configure`--no-javascript-evaluation` or\nturn off JavaScript execution tools to inspect pages without evaluating\nscripts, extending across navigations and initialization scripts.\n- **On-demand source maps** : Added an option to disable source maps and\nlazy-load source maps on demand, preventing high memory usage on large\nsites.\n- **Configurable file system roots and CLI path permissions** : The CLI now\nincludes`--allow-unrestricted-paths` by default and supports configurable\nfile system roots.\n- **Heap snapshot inspection** : Query objects directly by retained size or\nproperty name with`query_heapsnapshot` , view self and retained sizes for\nedges, and inspect memory retained by V8 execution contexts.\n- **PWA automation tools** : Added dedicated tools for automating Progressive\nWeb App installation and lifecycle checks.\n- **Console stack traces** : Retrieve optional stack traces when listing\nconsole messages with`list_console_messages` .\n\nLearn more in the [chrome-devtools-mcp\nrepository](https://github.com/ChromeDevTools/chrome-devtools-mcp).\n\n## Application: Ad script tracking in the Ads section, and cookie flag editing\n\nFollowing the introduction of four experimental ad metrics for the Chrome User Experience Report (CrUX), this new sub-panel is a centralized location to debug and optimize page-wide ad-related information. This includes:\n\n- A dashboard for the new experimental metrics: Viewport ad density, Viewport ad count, Total CPU usage by ads, Total network usage by ads.\n- Segmentation of CPU and network usage by ads elements\n- A table of ads scripts in the main frame.\n- A toggle that highlights ads on the page.\n\nLearn more about the new ad metrics in our [documentation](https://developer.chrome.com/docs/ads).\n\nChromium issues: [514957134](https://crbug.com/514957134),\n[512927903](https://crbug.com/512927903),\n[540469610](https://crbug.com/540469610)\n\n## Performance: Full soft navigation support, CPU performance tier overrides, and extension track search\n\nThe **Performance** panel offers end-to-end soft navigation measurement,\nhardware calibration overrides, and deeper trace search:\n\n- **Full soft navigation support** : Following the introduction of soft\nnavigation support in Live Metrics and trace views in[Chrome\n152](https://developer.chrome.com/blog/new-in-devtools-152#performance_soft_navigation_metrics_in_live_metrics_and_custom_screenshot_presets) ,\nsoft navigation analysis is now available in**Insights** , completing full\nend-to-end support for measuring soft navigations in the**Performance** panel.\n- **CPU performance tier override over CDP** : DevTools now supports\nconfiguring, calculating, and dispatching calibrated CPU performance tier\noverrides over Chrome DevTools Protocol\n(`Emulation.setCPUPerformanceOverride` ), enabling reproducible performance\ntesting across hardware tiers.\n- **Extension track search in flame chart** : Pressing`Ctrl+F` in the**Performance** panel flame chart now matches entries in custom tracks\nregistered using the Extensibility API, searching their tooltip text,\nproperties, and user details.\n- **CPU profile thread visualization** : The**Performance** panel flame chart\nnow renders threads that contain only CPU profile samples, ensuring\nbackground executions such as WebAssembly threads appear in timeline views.\n\nChromium issues: [449760252](https://crbug.com/449760252),\n[483092899](https://crbug.com/483092899),\n[540020488](https://crbug.com/540020488)\n\n## Elements: Inactive styles, keyboard-accessible adorners, and tree outline fixes\n\nInspecting and authoring CSS is faster and more accessible in the **Elements**\npanel:\n\n- **Inactive styles support** : DevTools can now continue showing style rules that\npreviously matched the selected element when they no longer apply, clearly\ndistinguishing them with an inactive visual indicator. Enable inactive styles\nand configure their collapsing behavior in**Settings** .\n- **Keyboard-accessible adorners** : Interactive adorners in the DOM\ntree—including**View Source** ,**Starting Style** ,**Scroll Snap** , and**Reveal** —are now keyboard focusable and can be activated using`Enter` or`Space` .\n- **Drag-and-drop reordering** : Reordering DOM nodes by dragging elements in\nthe DOM tree now functions reliably across shadow DOM boundaries, with clear\ndrop placement indicators.\n- **Smoother CSS property toggling** : Toggling CSS property checkboxes in the**Styles** tab no longer triggers duplicate UI repaints or visual flashing.\n\nChromium issues: [539424116](https://crbug.com/539424116),\n[554057179](https://crbug.com/554057179),\n[555088527](https://crbug.com/555088527),\n[548477554](https://crbug.com/548477554)\n\n## Device Mode: Modernized device presets grouped by form factor\n\nThe **Device Mode** toolbar and **Settings** > **Devices** view organize\nemulated hardware into clear categories:\n\n- **Form factor grouping** : Emulated devices are now grouped into**Mobile** ,**Foldables** ,**Tablets & Desktops** , and**Smart Displays** .\n- **Updated hardware catalog** : Added modern presets—including iPhone 16,\nPixel 9, Pixel 10, Galaxy Z Fold 6, iPad Pro 13\", and Nest Hub Max—while\nretiring outdated legacy device definitions.\n\nChromium issues: [526856234](https://crbug.com/526856234),\n[526857820](https://crbug.com/526857820)\n\n## Network: Edit and resend as fetch in Console, and local overrides security\n\nNetwork request inspection and debugging workflows have been streamlined and secured:\n\n- **Edit and resend as fetch in Console** : Selecting**Edit and resend as\nfetch** on any network request now automatically focuses the**Console** panel with the`fetch()` expression already pasted into the prompt, complete\nwith parameter comments and a reference link to the original request.\n- **Local overrides security hardening** : The**Network** panel now prevents\npath traversal (`%2E%2E` ) in local overrides and prohibits creating\noverrides on non-http(s) schemes like`data:` ,`blob:` ,`javascript:` , and`about:` .\n- **Caret escaping in Copy as curl (cmd)** : Copying network requests as curl\ncommands for Windows`cmd.exe` now caret-escapes parentheses and backticks,\npreventing command syntax errors when pasted into alternative shells.\n- **Binary payload cursor synchronization** : The**Payload** tab maintains\nyour scroll and cursor position when switching between Hex, Base64, and\nUTF-8 views.\n\nChromium issues: [40726969](https://crbug.com/40726969),\n[513843792](https://crbug.com/513843792),\n[513836026](https://crbug.com/513836026),\n[407750982](https://crbug.com/407750982)\n\n## Memory: Heap snapshot edge filtering, size sorting, and object querying\n\nThe **Memory** panel provides more granular tools for analyzing heap snapshots:\n\n- **Edge sorting and filtering** : You can now filter edges in heap snapshots\nby a minimum retained size and filter out primitive values (`null` ,`undefined` ,`true` ,`false` ) to focus on meaningful object references.\nEdges can be sorted by retained size, self size, or name.\n- **Direct object querying** : DevTools supports querying heap snapshot objects\ndirectly by retained size threshold or property name, streamlining memory\nleak investigations.\n- **Context retention analysis** : Heap snapshots can calculate and report the\naggregate memory kept alive specifically by V8 execution contexts.\n- **Resilient snapshot parsing** : Invalid or corrupted heap snapshot files now\nsurface clear errors rather than causing parsing hangs.\n\nChromium issues: [497855658](https://crbug.com/497855658)\n\n## Accessibility improvements\n\nChrome 153 and Chrome 154 include the following accessibility enhancements:\n\n- **Elements** : VoiceOver on macOS now announces \"expanded\" and \"collapsed\"\nstate changes through a polite live region when navigating DOM tree items.\n(Chromium issue:[540028208](https://crbug.com/540028208) )\n- **Issues** : Resolved duplicate screen reader announcements in the**Issues** counter, reading a single clean summary and applying correct non-button\nsemantics within the**Issues** panel. (Chromium issue:[536977880](https://crbug.com/536977880) )\n- **Elements** : Interactive adorners (**View Source** ,**Starting Style** ,**Scroll Snap** , and**Reveal** ) are fully focusable and activatable using\nthe keyboard. (Chromium issue:[554057179](https://crbug.com/554057179) )\n- **Live regions** : Added the`AccessibilityAnnouncementRecordingView` to\nrecord and debug live announcements and`ariaNotify` calls. (Chromium issue:[527462118](https://crbug.com/527462118) )", "url": "https://wpnews.pro/news/new-in-devtools-october-2026", "canonical_source": "https://developer.chrome.com/blog/new-in-devtools-october-2026?hl=en", "published_at": "2026-09-22 07:00:00+00:00", "updated_at": "2026-10-12 15:48:05.105988+00:00", "lang": "en", "topics": ["developer-tools", "ai-agents", "agent-protocols", "ai-tools"], "entities": ["Chrome 153", "Chrome 154", "Chrome DevTools MCP server", "Agent Plugins 1.0", "Chrome User Experience Report (CrUX)", "Chrome DevTools Protocol", "Google", "chrome-devtools-mcp repository"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/new-in-devtools-october-2026", "markdown": "https://wpnews.pro/news/new-in-devtools-october-2026.md", "text": "https://wpnews.pro/news/new-in-devtools-october-2026.txt", "jsonld": "https://wpnews.pro/news/new-in-devtools-october-2026.jsonld"}}