View, edit, OCR, organize, compare, fill, sign, and batch process PDFs
locally, privately, and without an account.
winget install killerpdfchoco install killerpdf4d03edc75472c6ef5d4d9c80a5da5143
Install or run portable. Free, open source, GPLv3.
No accounts or subscriptions required.
No telemetry is sent and no ads... ever.
The people's editor
Much of what KillerPDF does was requested by the people who use it. The GitHub issues page is open to anyone, so anybody can request a feature or report a bug.
Your suggestions genuinely shape where this goes next. Read the story behind the app on the About page.
Informational Brochure (PDF)
Built from scratch
KillerPDF is written in C# and WPF on .NET. It renders through PDFium and runs OCR on Tesseract, with extra language models downloaded only on demand so the base download stays small.
PDF creation, editing, validation, encryption, and writing are powered by The KillerPDF.Engine, an independent .NET library built from scratch for PDF 2.0 and modern PDF/A. The Technical page shows how it all fits together.
Fully featured
- Four view modes across unlimited tabs
- Split panes show two documents side by side
- Text, highlights, drawing and shapes
- Edit text inline and OCR scans
- Fill and sign PDF forms
- Stamp page numbers and watermarks
- Crop, transform, merge and split
- Compare PDFs page by page
- Print with full control, or flatten
What it does
View & navigate
PDFium rendering with four view modes - single page, continuous scroll, two-page with optional book layout, and a grid of every page. Open several PDFs in tabs, with search, outlines, and clickable links.
Search & select text
Search the whole document with every result highlighted as you scroll. Text selection follows columns and reading order, so copying one column no longer pulls in the next.
Annotate & edit
Inline text editing with font matching, plus text boxes, freehand drawing, lines, shapes with optional fill, and text-hugging highlights - each with its own color, opacity, and width. A full RGB color picker on every swatch.
OCR built in
OCR a page or a dragged region to the clipboard, make a scanned PDF searchable, or extract all text to a file. Tesseract ships in the exe; extra languages download on demand.
Forms & signing
Fill PDF forms and save them back. Draw reusable signatures, or sign with a cloud certificate (Certum SimplySign) and click-to-sign form fields.
Organize pages
Merge PDFs and split out pages, drag to reorder, rotate, extract, and stamp page numbers. Drop a folder or .zip to merge everything inside into one PDF or open each separately.
Split pane
F10 shows two documents side by side in one window, sharing the same toolbar and sidebar while keeping independent view and invert settings. Drag a tab from one pane to the other, and F10 again closes the split.
Opens anything
Opens password-protected PDFs by prompting instead of erroring, and repairs damaged or broken-xref files so they open and print.
Transform
Rotate, scale, flip, straighten with a level line, correct perspective, and tune levels - all with a live preview, while annotations follow the page.
Print & flatten
A real in-app print preview with printer paper and source controls, collapsible layout and output sections, scale, margins, N-up, subsets, duplex, and live preparation and spool progress at 300 DPI. Or flatten or export pages as images.
Stamps & watermarks
Stamp page numbers or a text watermark across any page range - positioned, sized, and styled - applied as a single undo.
Automation & command line
Merge, split, decrypt, resize, flatten, print, OCR, or batch-resave files from PowerShell or cmd without opening a window. Every command returns a script-friendly exit code.
Document info
View and edit a PDF's title, author, subject, keywords, and creator metadata, saved back into the file.
Install or run portable
Drop the exe anywhere and run it, or use the built-in installer - per-user with no admin rights, or for everyone on the computer (needs an administrator). You can also grab it from the command line:winget install killerpdf
Themes & languages
Thirteen themes - Dark, Light, Black, 98SE, Blood, Greed, Cyanotic, Ectoplasm, Decay, Malaise, Sepulchre, Delirium and Mourning - all switchable live. Four of them - Dark, Light, Black and 98SE - each take one of six accent colors, so 33 looks in all. UI localized in fifteen languages, including Kazakh, Polish, Hungarian and Russian.
The.Engine
KillerPDF 1.8 replaces its legacy document pipeline with The KillerPDF.Engine: an independent .NET library built from scratch for PDF 2.0 and modern PDF/A. It reads, validates, creates, edits, signs, encrypts and writes PDFs through the same public API available to other applications.
Explore the engine and developer guide
TheCorpus
The KillerPDF Corpus is an open, versioned collection of real-world, standards, malformed, and deliberately stressful PDFs. It makes reliability measurable and gives KillerPDF, qpdf, and other PDF tools the same repeatable test inputs.
KillerPDF 1.8.4 saved 40,563 PDFs across the same 47,024 inputs as 1.8.3, with identical outcomes and no crashes or timeouts.
Explore the latest results and benchmark guide