Hyperlinks

Hyperlinks in documents

SumatraPDF supports embedded hyperlinks stored in the file and auto-detected links it finds in plain text, in PDF and other documents. The two kinds behave and are controlled differently.

Click a link to follow it, and press Alt + Left to come back.

Embedded hyperlinks: created by the document author, they jump within the file, open another file, or open a URL
Auto-detected links: plain-text URLs, email addresses and DOIs become clickable. Disable them with DisableAutoLinks
Navigate back / forward: Alt + Left / Alt + Right
Preview a citation: hover a [1], footnote or figure reference to see its target in a popup. See Citation hover preview
Restrict links: LinkProtocols in sumatrapdfrestrict.ini

Follow a link #

Click it. Embedded hyperlinks are part of the PDF file, created by the author in Word, LaTeX, Acrobat or another program, and they work in every standards-compliant viewer. They can:

jump to another page or destination in the same file
open another file
open a URL in the default browser (http://, https://, mailto: and so on)

SumatraPDF also turns plain text that looks like a URL, email address, or DOI into a clickable link, even when the PDF contains no hyperlink annotation. For example, exporting www.example.com as plain text from a word processor creates a clickable link in SumatraPDF but not necessarily in every other viewer. A printed DOI such as 10.1109/WICSA.2015.29 opens as https://doi.org/10.1109/WICSA.2015.29.

Auto-detection follows a long-standing PDF viewer convention, and Adobe Reader does something similar.

Go back after following a link #

Internal links (footnotes, table of contents, cross-references) move you within the document. To return:

Alt + Left or Backspace: go back in navigation history
Alt + Right or Shift + Backspace: go forward

See Scrolling and zooming.

Preview a citation without leaving the page #

Hover a [12] citation, footnote marker or figure reference to see its target in a popup, without jumping to it. It is off by default. See Citation hover preview for turning it on and for scrolling and zooming the popup.

Disable auto-detected links #

Users who treat unexpected links as a security concern often ask about disabling them. See discussion #5703.

In advanced settings set:

DisableAutoLinks = true

Save the settings file. Embedded hyperlinks in the PDF file are not removed. Only automatic detection of text that looks like a URL, email addresses, and plain-text DOIs is disabled.

Block following links (restricted mode) #

In restricted mode, sumatrapdfrestrict.ini controls which links open. LinkProtocols defaults to http,https,mailto.

Disable opening URLs from documents entirely:

[Policies]
DiskAccess = 0

or narrow allowed protocols:

LinkProtocols =

An empty LinkProtocols value blocks all protocol handlers. An empty value is stricter than DisableAutoLinks, because it affects embedded links as well as auto-detected ones.

See Configure for restricted use and the full restrict.ini reference.

Tips #

Use Alt + Left to return after jumping to a footnote or cross-reference.
Use the citation hover preview to read a reference without jumping to it at all.
Use DisableAutoLinks = true to stop plain text becoming clickable while keeping the author’s links.
Use an empty LinkProtocols in restricted mode to block all links, embedded ones included.

Reference #

CHM and EPUB #

CHM files use HTML links, and some ms-its: links open topics inside the help file.
EPUB links are HTML anchors; external URLs open in the browser.