Okular vs SumatraPDF

Okular9.2Visit SumatraPDF9.0Visit

Higher score Okular #2 in PDF Readers 9.2/10 Free plan Free plan✓ 3 of 4 features Visit KDE

vs

SumatraPDF #4 in PDF Readers 9.0/10 Free plan Free plan✓ 4 of 4 features Visit SumatraPDF

• Okular fits best

  Free open-source desktop PDF reading

• SumatraPDF fits best

  Portable Windows reading with signatures

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Side by side

Feature	Okular 9.2/10 Visit ↗	SumatraPDF 9.0/10 Visit ↗
At a glance
Editor score	9.2	9.0
Ranking	#2 in PDF Readers	#4 in PDF Readers
Best for	Free open-source desktop PDF reading	Portable Windows reading with signatures
Pricing model	Free	Free
Starting price	Free plan	Free plan
Free plan	✓	✓
Free trial	—	—
Deployment	Desktop	Desktop
Platforms	Windows, macOS, Linux	Windows
Built for	Solo, Small business, Mid-market, Enterprise	Solo, Small business, Mid-market
Features Okular 3/4 · SumatraPDF 4/4
Annotation tools	✓	✓
Form filling	✓	✓
Offline access	Not checked yet	✓ (best)
Text-to-speech	✓	✓
Specs
OCR support	Not checked yet	Not checked yet
Platform support	Cross-platform	Desktop
Our review
Pros	Free and open source across Windows, macOS and Linux Annotations, form filling and digital-signature support Text-to-speech, presentation mode and multi-format viewing	Opens PDFs, ebooks, comics, images, and several document formats Supports annotations, digital signatures, and Windows text-to-speech Portable deployment and command-line PDF operations support local workflows
Cons	No OCR capability is included No integrations are supplied Focused on desktop platforms rather than broader access	Windows-only, with no macOS, Linux, web, or mobile versions Cannot fill PDF forms, despite supporting form-field highlighting Scanned pages require OCR elsewhere
Our verdict	Okular is a free, open-source document viewer from KDE for people who need more than basic PDF reading on a desktop. It opens PDFs alongside PostScript, TIFF, DjVu, images, XPS, EPUB, comic-book formats and other documents. Navigation… Read the review →	SumatraPDF is a free, open-source desktop reader for Windows. It is aimed at people who want to read PDFs and a broad set of other local formats, including EPUB, MOBI, CBZ, DjVu, XPS, CHM, and image files. Text search, document navigation,… Read the review →

Strengths and trade-offs

• Okular — where it wins

  • Free and open source across Windows, macOS and Linux
  • Annotations, form filling and digital-signature support
  • Text-to-speech, presentation mode and multi-format viewing

  Where it doesn't

  • No OCR capability is included
  • No integrations are supplied
  • Focused on desktop platforms rather than broader access

• SumatraPDF — where it wins

  • Opens PDFs, ebooks, comics, images, and several document formats
  • Supports annotations, digital signatures, and Windows text-to-speech
  • Portable deployment and command-line PDF operations support local workflows

  Where it doesn't

  • Windows-only, with no macOS, Linux, web, or mobile versions
  • Cannot fill PDF forms, despite supporting form-field highlighting
  • Scanned pages require OCR elsewhere

• Okular9.2/10 · Free plan

  A capable open-source desktop reader with annotations, forms, signatures and accessibility tools.

  Visit KDEFull verdict →
• SumatraPDF9.0/10 · Free plan

  A portable Windows reader with broad format support, annotations, signatures, and command-line tools.

  Visit SumatraPDFFull verdict →