# Sumatra PDF

Application: Krzysztof Kowalczyk

Also called sumatra, sumatra pdf reader

Krzysztof Kowalczyk, Productivity

A small free PDF, ePub, and comic reader. The process is SumatraPDF.exe. It is not Adobe Acrobat.

## What you need to know

Sumatra reads PDFs. Acrobat edits them.

SumatraPDF.exe is a small viewer for PDF and several ebook formats. Adobe Acrobat is the paid editor. Reader is Adobe's free viewer. Neither Adobe exe is this project.

- **What is it?**: Document reader

  **Still current?**: Yes, see Current status

  **Official download?**: Use the vendor link in this article

Feex says

If you only need to read the file, I would open SumatraPDF.exe before I install Acrobat. Editing a PDF is a different product.

## What is Sumatra PDF?

Sumatra PDF is a lightweight reader. SumatraPDF.exe opens PDF, EPUB, MOBI, XPS, and comic archives. Adobe Acrobat is a paid editor. This app will not replace Acrobat's edit tools.

## If you have never used it

If you only need to read a PDF, EPUB, or CBZ without Adobe's editor, this is Sumatra PDF, not Acrobat. Download it from sumatrapdfreader.org. Acrobat.exe is the paid editor. Acrobat Reader is Adobe's free viewer and a heavier install. Sumatra does not fill forms the same way and does not edit PDFs.

## What is it used for?

**Fast PDF reading**

Open a PDF without Creative Cloud. Acrobat is the editor people confuse with any PDF window.

**EPUB and comics**

ePub and CBZ in the same reader. Adobe Acrobat is not an ebook library.

**Portable copy**

A zip build exists. That is still Sumatra, not a portable Acrobat.exe.

## Who is it for?

- People who want a tiny reader
- Users who also open EPUBs and CBZ files
- Anyone who should not pay for Acrobat just to read a syllabus PDF

## Current status

Actively developed. This article is the Windows reader, not a PDF editor.

## How old is it?

Krzysztof Kowalczyk started Sumatra PDF in 2006 as a small MuPDF-based reader. Adobe Acrobat dates to 1993 as a paid editor. They are not the same product family.

## Versions

Major channels first. Exact build numbers are not all verified here.

Installer

Portable

## System requirements

Values follow the publisher's public guidance. Workload still changes the real need.

### Minimum

| Operating system | A current supported Windows 10 or Windows 11 release, per the vendor |
| ---------------- | -------------------------------------------------------------------- |
| RAM              | Enough for Windows plus this app. Heavy projects want more.          |

## Resource profile

- **CPU demand**: Follows what you open inside the app

  **RAM demand**: Follows documents, tabs, or libraries

## Installed processes

These executables belong to this product when it is installed.

| SumatraPDF.exe | Reader window |
| -------------- | ------------- |

## Startup components

Sumatra starts when you open a file. It should not start with Windows.

## File locations

| Typical install | C:\Program Files\SumatraPDF\SumatraPDF.exe |
| --------------- | ------------------------------------------ |

## File formats

PDF, EPUB, MOBI, CBZ, XPS

## Common problems

### Form fields or signatures missing

Sumatra is a reader. Use Acrobat, Reader, or another editor for filled forms.

### People download Acrobat when they wanted a tiny viewer

get.adobe.com/reader is Adobe. sumatrapdfreader.org is this app.

## Getting unstuck

### Install from sumatrapdfreader.org only

Search ads for "PDF reader free" often push other toolbars. The project site is the source.

### Set a default app in Windows Settings if PDFs still open in Edge

That is a file association, not a broken Sumatra install.

### If you needed to edit text in the PDF, use Acrobat or another editor

Sumatra will not grow those tools. That is the sibling-swap test with Acrobat.

## Alternatives

Adobe Acrobat Reader, Foxit PDF Reader, and Edge overlap for viewing. Acrobat Pro is the paid editor sibling.

## Official help and downloads

Start with the vendor. Random exe sites are not a support channel.

| Download      | [www.sumatrapdfreader.org/download-free-pdf-viewer ](https://www.sumatrapdfreader.org/download-free-pdf-viewer)Official installer or vendor page |
| ------------- | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| Help          | [www.sumatrapdfreader.org/docs/ ](https://www.sumatrapdfreader.org/docs/)Vendor support                                                          |
| Official site | [www.sumatrapdfreader.org/download-free-pdf-viewer ](https://www.sumatrapdfreader.org/download-free-pdf-viewer)Start here, not a random exe host |

## Related hardware

A small reader. Huge scanned PDFs want RAM. A GPU is optional.

## Technical details

Technical details

Vendor version numbers change. This article does not pin a build.

## Related

These entities connect to this article. Type is shown on every link.

[Adobe Acrobat: Application](https://feex.it/wiki/software/adobe-acrobat)[How to read Task Manager: Guide](https://feex.it/wiki/software/system/how-to-read-task-manager)

## Sources and verification

Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. [How we research](https://feex.it/wiki/research).

- [Sumatra PDF official site ](https://www.sumatrapdfreader.org/download-free-pdf-viewer)· Vendor product page
- [Sumatra PDF help ](https://www.sumatrapdfreader.org/docs/)· Vendor support
- [Foxhole process map ](https://foxhole.feex.it/)· First-party samples on Windows PCs. Not a lab benchmark.

## Was this article useful?

A yes or no is enough. Pick a reason if you want, or add a short note.

Quick facts

The short identity of this page. Specs, sources, and the full story stay in the article.

- **Developer**: Krzysztof Kowalczyk

  **Category**: Document reader

  **Process**: SumatraPDF.exe

  **License**: GPL free software

  **First released**: 2006

  **Official site**: [sumatrapdfreader.org](https://www.sumatrapdfreader.org/download-free-pdf-viewer)

  **Mapped by Feex**: Seen on Windows PCs in Foxhole

Feex Reviewed: Last verified August 2026

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Source: [Canonical Feex Wiki page](https://feex.it/wiki/software/sumatra-pdf/)

[Developer guide](https://feex.it/wiki/developers/) | [API policy](https://feex.it/developers/api-policy/) | [Agent guidance](https://feex.it/wiki/llms.txt)