Okular

{{Infobox software

| name = Okular

| logo = Breezeicons-apps-48-okular.svg

| logo size = 64px

| screenshot = Okular 21.12.1 screenshot.png

| caption = Okular displaying a PDF file on KDE Plasma 5

| author = Piotr Szymański

| developer = KDE

| released = {{Start date and age|2005}}[http://developer.kde.org/summerofcode/soc2005.html KDE Developer's Corner - Google Summer of Code 2005 Projects] {{webarchive|url=https://web.archive.org/web/20060628143503/http://developer.kde.org/summerofcode/soc2005.html |date=2006-06-28 }}[http://developer.kde.org/summerofcode/okular.html KDE Developer's Corner - Okular] {{webarchive|url=https://web.archive.org/web/20051211001827/http://developer.kde.org/summerofcode/okular.html |date=2005-12-11 }}

| latest release version = {{wikidata|property|preferred|references|edit|Q1165933|P348|P548=Q2804309}}

| latest release date = {{wikidata|qualifier|preferred|single|Q1165933|P348|P548=Q2804309|P577}}

| latest preview version = {{wikidata|property|preferred|references|edit|Q1165933|P348|P548=Q51930650}}

| latest preview date = {{wikidata|qualifier|preferred|single|Q1165933|P348|P548=Q51930650|P577}}

| programming language = C++

| operating system = Linux, Unix-like, Windows

| genre = Universal document viewer

| license = GPL-2.0-only or GPL-3.0-only

| website = {{URL|https://okular.kde.org}}

}}

Okular is a free and open source multiplatform document viewer developed by the KDE community based on the Qt and KDE Frameworks libraries. It is distributed as part of the KDE Applications bundle. It replaced KPDF, its main predecessor, alongside KGhostView, KFax, KFaxview and KDVI in KDE 4. Its functionality can be embedded in other applications.

History

Okular was started for the Google Summer of Code of 2005 by Piotr Szymański. Okular was identified as a success story of the 2007 Season of Usability.[http://season.openusability.org/index.php/2007/09/30/success-stories-07-okular/ Season of Usability] {{Webarchive|url=https://web.archive.org/web/20130925145241/http://season.openusability.org/index.php/2007/09/30/success-stories-07-okular/ |date=2013-09-25 }} Published on September 30th, 2007 by Ellen Reitmayr » Okular In this season, the Okular toolbar mockup was created based on an analysis of other popular document viewers and a usage survey.

When it was ported to Qt 5 in December 2016, the version numbering jumped from 0.26 to 1.0.{{Cite web|url=https://okular.kde.org/news.php#itemOkular12released|title = News}}

Since September 2019, Okular has been available in the Windows Store.{{Cite web|url=https://www.microsoft.com/en-us/p/okular/9n41msq1wnm8|title = Get Okular| website=Microsoft }}

In December 2020, the software versioning scheme was changed from sequence-based identifier to CalVer.

In February 2022, Okular was awarded the Blue Angel environmental label award by the German government for sustainable software design.{{Cite web|url=https://eco.kde.org/blog/2022-03-16-press-release-okular-blue-angel/|title=First Ever Eco-Certified Computer Program: KDE's Popular PDF Reader Okular|author=Joseph P. De Veaugh-Geiss|date=16 March 2022 }}{{Cite web|url=https://opensource.com/article/22/4/linux-kde-eco-certification-okular|title=Linux KDE receives first-ever eco-certification for Okular|website=Opensource.com}}

Okular for Windows

Okular is also available for Windows and can be installed from the Microsoft Store with a click.{{cite web|access-date=2025-03-28 |date=2025-03-28 |language=en |publisher=Microsoft |title=Okular |url=https://apps.microsoft.com/detail/9n41msq1wnm8?ocid=webpdpshare&hl=en-gb&gl=EN |website=Microsoft Store}} As this version is often not the most recent version, more current "test versions" may be downloaded as an .exe file from the project's website.{{cite web|access-date=2025-03-28 |title=Index of /ci-builds/graphics/okular/master/windows |url=https://cdn.kde.org/ci-builds/graphics/okular/master/windows/}}

Features

Okular's annotation features include commenting on PDF documents, highlighting and drawing lines, geometric shapes, adding textboxes, and stamps. Annotations are stored separately from the unmodified PDF file, or (since version 0.15 with Poppler 0.20{{cite web|title=Bug 151614 - store annotations with documents|url=https://bugs.kde.org/show_bug.cgi?id=151614|url-status=dead|archive-url=https://web.archive.org/web/20140819111812/https://bugs.kde.org/show_bug.cgi?id=151614|archive-date=2014-08-19}}) can be saved in the document as standard PDF annotations.

Alongside regular text selection, rectangular selections can be copied or saved as images by right-clicking and dragging. Other features include reading text aloud using the Qt Speech module part of Qt since Qt 5 (previously using the Jovie,{{Cite web|url=https://www.linux.com/news/3-alternatives-adobe-pdf-reader-linux|title=3 Alternatives to the Adobe PDF Reader on Linux|website=Linux.com {{!}} The source for Linux information|date=20 October 2014|language=en|access-date=2018-09-14}}[https://www.kde.org/applications/utilities/jovie/ Jovie on KDE.org]), trimming of white page borders, printing documents with a printer or to a PDF file, shifting colors, and bookmarks.

=Supported file formats=

Portable Document Format (PDF) with the Poppler backend
PostScript with the libspectre backend
Tag Image File Format (TIFF) with the libTIFF backend
Microsoft Compiled HTML Help (CHM) with the libCHM backend
DjVu with the DjVuLibre backend
Device independent file format (DVI)
XML Paper Specification (XPS)
OpenDocument format (ODF) (only OpenDocument Text)
FictionBook (*.fb2)
ComicBook
Plucker
ePub
Mobipocket
Various image formats, such as JPG
Markdown[https://www.kde.org/announcements/fulllog_applications.php?version=17.12.0#okular KDE Applications 17.12.0 Full Log Page][http://okular.kde.org/formats.php Okular - Document format handlers status]

The official version obeys the DRM restrictions of PDF files by default, which may prevent copying, printing, or converting some PDF files. However, this can be turned off in the options under "Obey DRM limitations".[http://manurevah.com/blah/en/blog/Okular-and-DRM Okular and DRM][http://tsdgeos.blogspot.com/2009/06/okular-pdf-and-drm.html Okular, PDF and file permissions][https://lwn.net/Articles/335415/ Okular, Debian, and copy restrictions][http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=531221 Debian Bug report logs - #531221 okular: Arbitrarily enforces DRM by default]