KillerPDF

Judgement

What it is

Complete system

What it does

A free Windows PDF editor with its own PDF engine for viewing, annotating, OCR, merging, splitting, editing text, signing, redacting and form filling.

Adopt it when

You want an Acrobat-style editor on Windows without a subscription and can accept a young project.

Watch out

Seven months old with a newly written PDF engine, so test rendering and redaction on important documents.

Ready for

Usable

Runs as

Desktop app

Built with

C#, .NET and WPF

How established

Young: started 6 months ago, latest release v1.9.2.

What the license allows

Use inside your business is unrestricted, but anything you distribute that includes it must be released under the same license.

Judged on 2026-11-03 from the project's README and GitHub data. The license and age lines are worked out directly.

Built from

Follow it down: KillerPDF → Runtime → LLVM project → runs on a microchip

How compilers were built, back to punched paper tape

Open-source alternatives to KillerPDF

1. 1
   PdfCraft storytold

   PdfCraft: An open-source PDF reader and editor written by scratch in pure Rust

   Complete system Experimental You want to try a fast native PDF workbench and do not need it to be dependable yet.

   ★ 19k Apache-2.0 Rust Active, pushed today
2. 2
   BentoPDF alam00000

   The Privacy First PDF Toolkit

   Complete system Usable Staff need everyday PDF tasks without uploading documents to online PDF services.

   ★ 16k AGPL-3.0 JavaScript Active, pushed today
3. 3
   OmniTools iib0011

   Self-hosted collection of powerful web-based tools for everyday tasks. No ads, no tracking, just fast, accessible utilities right from your browser!

   Complete system Usable You want an ad-free in-house replacement for the scattered online converter and formatter sites staff use.

   ★ 11k MIT TypeScript Active, pushed 9 days ago
4. 4
   Pdfcpu pdfcpu

   PDF tooling for Go and the command line.

   Building block Production-ready You need to script PDF manipulation in Go services or shell pipelines.

   ★ 8.9k Apache-2.0 Go Active, pushed today
5. 5
   Pdfarranger pdfarranger

   Small python-gtk application, which helps the user to merge or split PDF documents and rotate, crop and rearrange their pages using an interactive and intuitive graphical interface.

   Complete system Production-ready You regularly reorganise PDF pages on Linux or Windows and want a simple free tool.

   ★ 6k GPL-3.0 Python Active, pushed 2 days ago
6. 6
   Qpdf qpdf

   qpdf: A content-preserving PDF document transformer

   Developer tool Production-ready You need reliable scripted PDF structural operations in a pipeline.

   ★ 5.5k Apache-2.0 C++ Active, pushed 37 days ago
7. 7
   PDFsam torakiki

   PDFsam, a desktop application to split, merge, mix, rotate PDF files and extract pages

   Complete system Production-ready You need reliable offline page-level PDF work on Windows, macOS or Linux at no cost.

   ★ 4.7k AGPL-3.0 Java Active, pushed 3 days ago
8. 8
   Pikepdf pikepdf

   A Python library for reading and writing PDF, powered by QPDF

   Building block Production-ready Python code needs to manipulate PDF structure, metadata, pages or encryption reliably, including damaged files.

   ★ 2.8k MPL-2.0 Python Active, pushed yesterday

Commercial PDF tools

1. 1
   Adobe Acrobat Adobe Inc.

   Adobe Acrobat is your complete PDF toolkit, enhanced with AI. Create, edit, sign, and manage all of your documents.

   Complete system Production-ready You work with PDFs daily, need full editing, forms and redaction, and want the format's own reference tool.

   2k readers a month Since 1993 Commercial
2. 2
   ABBYY FineReader ABBYY

   ABBYY's latest AI-based OCR technology powers this PDF editor software. Use tool to convert files (PDF to Excel, PDF to Word, etc.), edit, share, collaborate & more!

   Complete system Production-ready You regularly need accurate OCR of scanned documents into editable formats on your own computer.

   143 readers a month Since 1993 Commercial
3. 3
   Foxit PDF Editor Foxit Software

   Foxit PDF Editor is an AI-powered PDF editor for editing, converting, and signing PDFs. Save 44% vs. Adobe Acrobat. Trusted by 700M+ users. Try it free.

   Complete system Production-ready A business needs Acrobat-level PDF editing across many seats for less money.

   Commercial
4. 4
   Nitro PDF Pro Nitro Software

   Simplify how your business works. Streamline document workflows, boost productivity, and ensure data security with Nitro

   Complete system Production-ready A company wants to replace Acrobat seats with a cheaper editor that includes e-signing.

   Commercial
5. 5
   Apryse SDK Apryse

   Integrate document processing capabilities into any software applications. Generate, convert, view, edit, and sign pdf and documents easily.

   Building block Production-ready Your product needs a full in-app document viewer and editor and you can pay for a commercial SDK.

   Commercial
6. 6
   Smallpdf Smallpdf

   Smallpdf - the platform that makes it super easy to convert and edit all your PDF files. Solving all your PDF problems in one place - and yes, free.

   Complete system Production-ready You need occasional quick PDF jobs in the browser without installing software.

   Commercial