Network+ for DevTools

Network analysis with sanitized HAR, retention limits, integrated search, accessible UI, and keyboard controls.

Network+ for DevTools adds a dedicated network-analysis panel to Google Chrome DevTools. It is designed for web developers, QA engineers, and support engineers who need to inspect HTTP evidence and share it safely without leaving the DevTools workflow. Sanitized output is the default for every copy and export action, non-UTF-8 responses are decoded with the correct character set, and any two captured requests can be compared side by side. The request grid captures traffic reported by the Chrome DevTools network API and presents method, status, domain, path, type, duration, size, initiator, URL, and optional waterfall information, with color-coded method badges and an optional Operation column that surfaces GraphQL operation names and JSON-RPC methods detected in request bodies. Users can sort and resize columns, choose visible columns, apply per-column filters, save the column-and-filter setup as a view preset, and run a multi-keyword search across URLs, headers, request bodies, and response bodies with match-case, whole-word, and regular-expression options, optionally narrowing the grid to matching rows only. Captured requests are kept across page navigations, so a redirect or reload does not wipe the evidence being examined; rows whose response bodies could not be retrieved in time are labeled rather than silently dropped. Selecting a request opens request and response inspectors for headers, bodies, query parameters, cookies, raw data, and timing phases, with the Body view rendering images, HTML, and JSON in place. Two selected requests can be compared side by side to isolate what changed between a working call and a failing one. The Body and Raw inspector views carry their own keyword search with hit counting, next/previous navigation, and an expand-all action that reveals matches hidden inside collapsed JSON nodes or truncated previews. Response bodies are decoded with the charset declared by the Content-Type header, falling back to a scan of the HTML meta charset, so non-UTF-8 payloads read correctly in both live capture and imported HAR or SAZ files. Scope and match options persist between sessions; search keywords themselves are never stored. The panel is not confined to the DevTools window. A pop-out action opens Network+ in a full browser tab that mirrors the live capture session, keeping rows, details, and the paused state in sync, which helps on small screens or a second monitor; an undocked DevTools window is minimized automatically at that moment, since capture continues inside it, and a docked DevTools stays as it is. The tab is a full remote control, not just a view: pause and resume, clear with undo, retention changes, HAR or SAZ import, stream capture, and re-sending all execute in the DevTools session over the same extension-internal port, and the tab reflects the session state within a second. An opt-in stream-capture mode records the WebSocket messages the inspected page sends and receives, and the Server-Sent Events it receives, on connections opened while the mode is on, listing them as directional frames in the inspectors; capture is observation only and never alters traffic. HAR files that include WebSocket messages recorded by Chromium-based DevTools are restored the same way on import, and captured conversations round-trip: full HAR exports write the frames back out in the same Chromium shape, while sanitized exports omit them with an explicit per-entry marker. A captured request can also be re-sent, either unchanged or after editing the method, URL, headers, and body in a dialog. The composed request is issued by the inspected page itself through the DevTools evaluation API, so cookies, CORS, and the page's security policies apply exactly as if the page had made the call, browser-managed headers remain browser-managed, and the reply arrives as a new captured row. A cURL command can also be pasted to prefill the same dialog; unsupported flags are refused by name rather than guessed. JWT-shaped header values such as Bearer tokens decode inline in the header panes with humanized expiry times, locally and for display only; signatures are not verified, and decoded claims never join copies or exports. Network+ applies local retention the reader controls. Request rows are retained without a count limit by default, and a limit from 100 to 100,000 can be configured in the Settings dialog, which states the memory cost of the unlimited default. Response bodies remain subject to a 1 MiB per-body limit and a 32 MiB shared cache limit. The status bar reports retention and body-cache conditions so omitted or evicted content is not presented as complete evidence. Clear removes the current working set and offers a bounded 10-second Undo action while retained data remains available. Clipboard copy and HAR export are user-initiated. Sanitized output is the default and redacts or omits sensitive fields according to the documented policy: a request can be copied as a sanitized one-line summary, a Markdown report ready for a bug tracker or chat, or a cURL, fetch, or PowerShell command, and exports can cover the rows currently displayed or only the selected rows. Full output is never the default. Full HAR export and the full body copies in the Request and Response panes require a warning and one-time confirmation for that action; the row menu's full copy formats are reached through a collapsed group labelled `Copy full (unsanitized)`, which names what it hands out at the point of choosing. Network+ does not save a full-output preference. Users should still review any exported or copied data before sharing it. An empty panel offers three deterministic, local-only sample requests under reserved `.test` domains. The sample sends no network traffic, pauses live capture to avoid mixing evidence, and includes a prompt-first guide for identifying a 503 request, its dominant Wait (TTFB) phase, a Retry-After header, and the limits of browser-observed timing. No account or test credentials are required. Network+ supports System, Dark, and Light themes, keyboard navigation, visible focus, screen-reader status announcements, responsive panel layouts, and reduced-motion preferences. A Settings dialog gathers language, theme, and capture retention; explanations and every dialog, including the item names in them, are available in Japanese, while toolbar buttons and column headers stay in English so written instructions still match the UI. It runs from packaged extension code without remote code, telemetry, analytics, advertising, or an external service. Network+ reports browser-observed HTTP timing; it does not prove packet loss, cabling or radio-frequency faults, or a definitive server root cause. Every feature is free. Optional GitHub Sponsors and Ko-fi links open in ordinary browser tabs; the extension embeds no checkout and receives no payment or account data.