Emacs: Command to Lookup Doc on Web 📜

By Xah Lee. Date: . Last updated: .

Command to Search Web, or Lookup Function Doc, Word Definition

put this in your Emacs Init File:

(defun xah-lookup-web ()
  "Lookup current word or text selection in web search.
URL `http://xahlee.info/emacs/emacs/emacs_lookup_ref.html'
Created: 2017-02-09
Version: 2026-01-07"
  (interactive)
  (let ((xword (if (region-active-p)
                   (buffer-substring-no-properties (region-beginning) (region-end))
                 (current-word t))))
    (browse-url (format "https://search.brave.com/search?q=%s" xword))))

This is useful when you are writing a major mode for a programing language. You want to provide a command that lookup function (the word under cursor)'s documentation.

To make this command search different search engine, you just need to change the URL.

Change browse-url to eww if you want to use emacs browser [see Emacs: eww web browser]