What exactly does a browser restart remove after using DuckDuckGo’s Fire Button—are there known residual artifacts?
Executive summary
The DuckDuckGo Fire Button is designed to clear local browsing state—tabs, history, cookies and storage—immediately in the app, and DuckDuckGo states that any remaining fragments can be removed by closing the browser [1]. Independent mobile-forensics reporting suggests the app performs secure deletions in its SQLite tab tables but can leave filesystem-level remnants such as freeblock headers in unallocated space unless the underlying storage is vacuumed or overwritten [2].
1. What the vendor says the Fire Button removes
DuckDuckGo’s own documentation describes the Fire Button as clearing “browsing history and tabs” along with ordinary cookies and browser storage kept in the app’s local storage, and it explicitly warns that Fireproofed sites keep 1st‑party cookies and storage intact by design [1]. DuckDuckGo also lists items the Fire Button will not clear—bookmarks, downloaded files, and DuckDuckGo Search settings and associated storage—and notes that users can configure auto-clear-on-restart behavior in settings [1]. The vendor further published a specific note about an OS WebView2 component bug that may delay instant clearing of fragments but maintains that the Fire Button itself still clears history and tabs and that closing the browser erases remnants [1].
2. What forensic analysis found about residual artifacts
A focused Android forensic writeup reports that when the app’s tab data is cleared or the Fire Button used, records in the Tabs SQLite table are “secure deleted” and that auto_vacuum is enabled so deleted rows are not simply left in place for reuse [2]. The same researcher observed that secure deletion creates freeblocks which can occupy cell content areas and that while the content area may be absorbed by subsequent operations, the app does not run a VACUUM command; consequently, freeblock headers may remain in unallocated space even after deletion—meaning structural remnants but not necessarily recoverable tab content may persist at the filesystem level [2].
3. How a browser restart factors into final cleanup
DuckDuckGo’s guidance states explicitly that any data remnants can be erased by closing the browser, implying that terminating the app and its renderer/webview processes allows the operating system or WebView component to release or overwrite transient storage where fragments might otherwise persist [1]. The vendor’s bug note about WebView2 further implies that, in some OS/component configurations, immediate clearing may appear incomplete until the browser process is closed and the platform-level component finishes its cleanup [1].
4. Where residual artifacts are most likely to show up
Available reporting narrows likely residual artifacts to low-level filesystem remnants—database freeblock headers and unallocated space that previously contained secure-deleted rows—rather than intact, user-readable histories or cookies left behind after the Fire Button is used, according to the forensic blog’s analysis of the Tabs table mechanics [2]. The vendor also makes clear that items intentionally excluded from the Fire Button—bookmarks, downloads, and fireproofed site data—will still exist after clearing [1].
5. Conflicting claims and practical implications
A public feature request and tracker describe the Fire Button at a conceptual level as deleting cookies, cache, and search history, reflecting user expectations that the feature aggressively wipes session data [3], while DuckDuckGo’s documentation and the forensic analysis together show nuance: the app aggressively clears in-app state but some platform-level remnants or intentionally preserved data (fireproofed sites, downloads) remain unless the browser is closed and platform storage is reclaimed [1] [2]. That means threat models differ: casual privacy from profiling is well served, but high-stakes forensic recovery on a seized device may still discover structural remnants or excluded data depending on OS, WebView implementation, and whether the app was closed after firing [1] [2].
6. What this reporting does not prove and remaining unknowns
The sources do not provide a comprehensive cross‑platform forensic sweep showing which exact bytes remain on every OS, nor do they present controlled recovery attempts that demonstrate full content recovery of deleted entries after a restart; therefore it cannot be concluded from these reports alone that user-readable artifacts are or are not recoverable in every environment [1] [2]. Independent, platform-specific forensic testing under controlled conditions would be required to fully map residual artifacts, and the available material stops short of that level of proof [2].