I've installed pdf-tools through MELPA, and it works like a charm. Funnily, and as is documented in the readme, the command pdf-tools-install needs to be run each time if you want pdf-tools to be enabled; (require 'pdf-tools) is not enough (the use of the word "install" in the command name is a little bit misleading). The only thing is, it takes 12 seconds or so to run pdf-tools-install from my init.el file (clocked using esup).

So what I've done is the following:

(with-eval-after-load 'tex
  (setq TeX-view-program-selection '((output-pdf "pdf-tools")))
  (setq TeX-view-program-list '(("pdf-tools" "TeX-pdf-tools-sync-view"))))

which allows it to only load when I'm in tex mode, which is nice. But it still means it takes an extra 12 seconds to load any tex file I want to work on, if I haven't loaded it in my current emacs session.

Call me impatient, but I literally moved to emacs from a more bloated editor in order to reduce startup times!! Is there any reason anyone can think of why it's taking so long to load pdf-tools-install, and a solution? Thanks in advance!

EDIT: Because of discussions following this issue, I replaced pdf-tools-install with (require 'pdf-tools) in my init.el just to make sure that pdf-tools-install is indeed required, and it seems that it is. Using (require 'pdf-tools) does not properly initiate pdf-tools, and pdfs are displayed using the normal DocView mode, rather than pdf-tools' PDFView mode.

  • 1
    You only need to install pdf-tools once, not every time you open a tex file.
    – Dan
    Commented Dec 23, 2017 at 16:17
  • according to the readme, pdf-tools-install needs to be in the init.el. When it is not, there is lots of missing functionality (synctex doesn't work, for instance)
    – sacuL
    Commented Dec 23, 2017 at 16:33
  • I just checked, it just ends up reverting to docview instead of using PDFview without running pdf-tools-install.
    – sacuL
    Commented Dec 23, 2017 at 16:44
  • Just run pdf-tools-install once and then put (require 'pdf-tools) in your init file.
    – Dan
    Commented Dec 23, 2017 at 16:57
  • @Dan, with (require 'pdf-tools), startup time is still about 12 seconds, and fails to work; auctex reverts to docview.
    – sacuL
    Commented Dec 23, 2017 at 17:14

2 Answers 2


Try setting the variable pdf-view-use-unicode-ligther to nil, according to the doc it speeds up the loading on systems where looking for the unicode symbols used in the mode line (⎙ and 🌙) takes a long time.

  • Amazing! That works perfectly. Thanks!
    – sacuL
    Commented Dec 23, 2017 at 17:13

After having pdf-tools installed (just once), put the following in your init file:

(add-hook 'doc-view-mode-hook 'pdf-tools-install) 

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