KillerPDF 1.5.1

KillerPDF is a lightweight, portable PDF editor for Windows built for users who want full control without subscriptions, installers, or telemetry. It runs as a single executable, making it ideal for USB use and field work. You can view PDFs with smooth PDFium rendering, navigate quickly with thumbnails, zoom, and shortcuts, and reorganize pages using drag-and-drop. It supports merging multiple PDFs, splitting documents, and extracting selected pages.

KillerPDF also allows inline text editing with font matching to preserve the original layout, plus annotations like text boxes, freehand drawing, highlights, and reusable signatures. You can search full text, copy content easily, and print documents with flattened annotations.

Designed as a free and open alternative to bloated PDF tools, it works fully offline on Windows 10/11 x64. No runtimes install. Everything needed is inside the EXE (targets .NET Framework 4.8, which ships with every supported Windows release).

KillerPDF key features:

• High-quality PDF rendering via PDFium
• Edit PDF text inline (double-click to modify text)
• Page thumbnails and fast navigation with zoom and shortcuts
• Merge multiple PDFs into one
• Split PDFs and extract selected pages
• Drag-and-drop page reordering
• Font matching to preserve original document appearance
• Text boxes for notes
• Freehand drawing tools
• Highlight overlays with adjustable color, size, opacity
• Undo actions and clear per-page annotations
• Create, draw, and save reusable signatures
• Click-to-place signatures anywhere
• Full-text search with highlighted results
• Drag-select or Ctrl+A to copy text
• Print with annotations flattened
• Portable single-file app (~10 MB)
• No installer, no admin rights required
• No account, no telemetry

KillerPDF 1.5.1 changelog:

Performance

• Save Flattened PDF now uses multiple CPU cores. Page rasterization is parallelized (PNG encoding runs across cores; the PDFium render step stays serialized since the library isn't thread-safe), so large documents flatten significantly faster while the UI stays responsive (#68).

Fixed

• PDFs that failed to open with "Unexpected EOF" now open (#72). The failure was PdfSharpCore's Flate inflater (SharpZipLib) rejecting the FlateDecode cross-reference stream on multi-revision PDFs - files that open fine in browsers, Acrobat, and Foxit. KillerPDF now detects this and re-opens the file losslessly through PDFium, preserving selectable text. Thanks to @javajon for the report and a detailed reproduction.
• Grid view renders every page. It was capped at the first 26 pages, so longer documents stopped loading partway through. Tiles also stream in progressively now instead of blocking until the whole document is rendered.
• Grid Ctrl+Scroll no longer reloads every page when the zoom is already at its limit and nothing would change.
• Removed a stray horizontal scrollbar (a thin green line) that could appear across the bottom of grid view.
• Files on UNC / network shares (including the WSL \\wsl$ filesystem) are copied locally before opening, avoiding partial-read failures on network filesystems.

Changed

• Minimum zoom lowered from 10% to 5%, so grid view can pack more columns (helpful for wide/landscape pages) and single-page view can zoom out further.

Download: KillerPDF 1.5.1 | 6.3 MB (Open Source)
Link: KillerPDF Home Page | Github | Screenshot

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