2018 update: Confirmed on Version 65.0.3325.181, you can simply right-click anywhere inside the devtools console and click “Clear console history.” It solved the problem for me. I ran into this issue earlier and, having never seen it before, began going through the first couple steps to TarranJones’ solution.
Firefox Firefox stores localstorage in webappsstore.sqlite file in the profile folder. Firefox (Windows XP): C:\Documents and Settings\<Windows login/user name>\Application Data\Mozilla\Firefox\Profiles\<profile folder>\webappsstore.sqlite Firefox (Windows Vista and above): C:\Users\<Windows login/user name>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile folder>\webappsstore.sqlite or: %APPDATA%\Mozilla\Firefox\Profiles\<profile folder>\webappsstore.sqlite Firefox on linux: ~/.mozilla/firefox/<profile folder>/webappsstore.sqlite Firefox on mac: ~/Library/Application Support/Firefox/Profiles/<profile folder>/webappsstore.sqlite or: ~/Library/Mozilla/Firefox/Profiles/<profile folder>/webappsstore.sqlite Chrome Chrome stores in separate files inside the … Read more