I here list my favorite keyboard shortcuts in text editors and browsers. Within each category, they’re ordered very roughly by how much I use them.

Editing text

Most of these should work in most text editors (including GDocs or even text fields in browsers).

• Ctrl + Right/Left Arrow navigates between words. (Similarly, Ctrl + Up/Down Arrow navigates between paragraphs, but I don’t use this nearly as much.)
• Ctrl + Backspace/Delete deletes the preceding or following word.
• Ctrl + X/C/V copies/cuts and pastes.
• Ctrl + Z undoes the previous action; Ctrl + Y and sometimes Ctrl + Shift + Z redo actions undone via Ctrl + Z.
• Ctrl + Shift + V pastes while ignoring the original formatting of the copied text.
• Shift + Right/Left Arrow marks text character by character. Ctrl + Shift + Right/Left Arrow marks text word by word. And so on.
• Ctrl + S saves the document and Ctrl + Shift + S saves a copy of the document in a new location.
• Ctrl + I/B/U puts marked text in italics/bold/underlined font.
• Ctrl + K adds a hyperlink to the currently marked text.
• Ctrl + F to find a specific string of characters.
• Ctrl + A marks the entire text.

Interestingly, there are also some harmful keyboard shortcuts. For example, Ctrl + D deletes the current line. Unfortunately, D lies between F, C, X and S (on US layout keyboards), all of which I use frequently, so I sometimes press Ctrl + D by accident. I never use Ctrl + D deliberately.

Browser

I use Firefox on Linux, but I believe the same shortcuts work in other browsers and on Windows, and analogous shortcuts work on Mac OS (with cmd instead of ctrl).

• Alt + Left Arrow: go back a page.
• Ctrl + Page Up/Down: navigate through open tabs.
• Ctrl + W to close the current tab.
• I use the plugin “Web Search Navigator” (available on Firefox and Chrome). This allows one to go through search results on Google, Google Scholar and others with the Up and Down Arrow keys.
• Ctrl + T to open a new tab.
• Ctrl + L to jump to the URL/Search line.
• Left-click on the backward button shows the history of the current tab.
• Middle-click or ctrl + left-click on a link opens the link in a new tab. This also works in some other contexts. For example, one can middle-click on the “backward” button to open the previous page in a new tab.
• Ctrl + N to open a new window.
• Ctrl + Shift + N/T reopens the window/tab that was last closed.
• Ctrl + F to find a specific string of characters.
• Ctrl + R or sometimes F5 refreshes the page.
• Alt + 9 switches to the last (right-most) tab.
• I occasionally use Alt + 1,2,3,4,5,6,7,8 to switch to the respective tab in a window. One way to use this would be to have some system for what is in those tabs. For example, one could always have one’s webmail open in tab 1. I don’t use such a system. To use this properly without a system one needs to have at most nine tabs open. Even with, say, nine tabs, it’s impractical because it is difficult to immediately see what, for example, the fourth tab is. Therefore, I mainly use it when I have an even smaller number of tabs, roughly 4-6, cf. the concept of subitizing.
• (Fn+)F11 switches to fullscreen mode.