TERMIUM / DOCUMENTATION

Developer tools, clipboard and extensions

These features are on the development branch main; they are not in the latest published release yet. Updating from source makes them available. See development setup and release availability.

Find the tools in Menu

Click Menu in the top bar or press F10. Use Up/Down (or Tab/Shift+Tab) and Enter, or click an item. Escape closes the menu. On short terminals, keep moving down to reveal the remaining entries.

Paste uses your terminal's paste command; there is no menu action that reads the host clipboard. Loading an unpacked extension uses --extension at launch; Extensions opens the manager, not a terminal file picker. Sound is still being investigated and has no playback or mute control in Menu yet.

Inspect a page

Press F12, or choose Developer tools from the F10 menu. Termium opens Chromium's built-in DevTools in a separate Termium tab, initially showing Elements. Use its panels to inspect HTML/CSS, run console commands, examine network requests, and debug scripts. Mouse and keyboard input work in the tools. Vimium does not run on this browser-internal page.

Switch between the page and its tools using the tab bar or F10 → All tabs. Ctrl+W closes the tools without closing the inspected page. Closing the inspected page also removes its tools. Termium keeps one inspector at a time; opening tools for another page replaces the previous inspector. No debugging TCP port is opened. Breakpoints pause the inspected page, so its frames and input can stop until you resume execution in DevTools.

Select, copy and paste

Select webpage text by dragging with the mouse, using mouse keys (F6, Space to hold/release a drag), or using the page's keyboard selection controls. Press F8 or Ctrl+C while page input is focused, or choose Copy selected text in F10. Text selections in inputs, textareas, focused frames and open shadow DOM are supported. Password fields are excluded. A selection may contain up to 64 KiB of UTF-8 text; empty selections leave the clipboard alone.

Copy uses the terminal's OSC 52 clipboard support. Your terminal must allow it; “Copy sent to terminal clipboard” confirms sending the request, not permission from the terminal. It also works over SSH when the local terminal supports OSC 52. Copy is plain text, not HTML or images, and does not grant webpages clipboard-read permission. Ctrl+C in the address editor retains its local editor behavior.

Paste with your terminal's paste shortcut (commonly Ctrl+Shift+V on Linux or Cmd+V on macOS). Termium forwards bracketed paste as literal text to the focused page input, including Unicode and newlines, without interpreting it as Vimium commands. A bare Ctrl+V key is not a portable request to read the host clipboard. Clipboard access from a website's own JavaScript remains subject to Chromium's permissions; this feature is the explicit Termium copy action.

Load extensions

Pass an unpacked Chromium extension directory containing manifest.json:

termium --extension /path/to/extension https://example.com
termium --extension /path/to/first --extension "/path/with spaces/second"

Directories are resolved from your current working directory. Requested extensions load before the initial page; Vimium remains installed. Invalid or incompatible extensions produce a browser-startup error rather than being skipped. Only load extensions you trust with the pages you browse.

Choose Extensions from F10 to view Chromium's extension manager, including extension details and options. Loading is session-specific: supply the arguments again on the next launch. This does not install CRX files or implement Chrome Web Store installation, toolbar action buttons, or profile persistence. With a remote Termium server, configure --extension on that server instead of the client.