StealthPDF is a free and open-source PDF editor for Windows. It can view, annotate, edit, OCR, merge, split, compress, stamp, fill, sign, unlock, print, and flatten PDFs locally - no account, no telemetry, and no cloud upload.
Website & downloads: stealthpdf.com · Source code: github.com/aabhpsy/StealthPDF
StealthPDF is a community fork and rebrand of the original KillerPDF project by Steve the Killer, released under GPLv3. This fork is maintained by @aabhpsy.
- High-quality PDF rendering via PDFium.
- Single Page, Continuous, Two-Page, and Grid view modes.
- Tabbed documents with per-tab page, zoom, view, search, annotation, form, and stamp state.
- Full-text search with highlighted results and drag-select text copy.
- Outline/bookmark navigation and clickable links.
- Fit to Width, Fit Page, zoom presets, mouse-wheel zoom, and full-screen mode.
- Recent files on the start screen and Open menu.
- Traditional File / Edit / View / Tools / Help menu bar plus an icon toolbar.
- Tooltips on toolbar buttons and a keyboard shortcut overlay.
- Localized UI in multiple languages, including English, English (UK), Nepali, Spanish, Chinese, German, French, Turkish, and Bengali.
- Add text/typewriter annotations with font, size, color, bold/italic/underline/strike, and optional background fill.
- Edit existing text-based PDF content with a cover-and-text replacement workflow that matches the detected text color and size where possible.
- Draw freehand ink, straight lines, and highlights with configurable color, width, and opacity.
- Insert images as resizable annotations and burn them into the saved PDF.
- Move, resize, multi-select, restyle, and delete annotations in place.
- Add page numbers and watermarks across a page range.
- Add certification stamps with configurable label, name, date/time, signature image, logo, border style, placement, and scale.
- Certification stamp fill is transparent by default; enable the fill box when a document needs a distinct backing panel.
- Stamp state is per document tab so applying a stamp to one PDF does not auto-apply it to another.
- Fill PDF form text fields, checkboxes, and radio buttons.
- Use Fill & Sign tools for free-placement text, checkmarks, and signatures.
- Store reusable signatures or import a one-off signature image.
- Save or flatten filled/signed PDFs.
- OCR a whole page or a dragged region straight to the clipboard.
- Make Searchable PDF by adding an invisible text layer over scanned pages.
- Extract all recognized text to
.txtor.md. - English and Nepali OCR models are bundled for fully offline use; other supported languages can be downloaded on demand and cached.
- Scan pages from WIA or TWAIN scanners into a new PDF.
- Choose DPI, color mode, flatbed/feeder options, and duplex where supported.
- Import images or combine selected files into a PDF.
- Merge PDFs, split/extract pages, rotate pages, crop pages, and reorder pages.
- Compress PDFs using the bundled compression helper.
- Repair damaged PDFs where possible.
- Open password-protected PDFs and save an unlocked/unencrypted copy when permitted.
- Print with preview and save flattened output.
- Single portable Windows EXE, or self-install per user to
%LOCALAPPDATA%\Programs\StealthPDF\. - No administrator rights required for normal use or per-user install.
- Registers as a PDF handler with branded icons when installed.
- Local-only processing: no account, no telemetry, no phone-home.
You can use the same EXE either way:
| Portable | Installed | |
|---|---|---|
| Admin rights | None | None |
| Location | Wherever you place it | %LOCALAPPDATA%\Programs\StealthPDF\ |
| Start Menu shortcut | No | Yes |
| Desktop shortcut | No | Optional |
| Open PDFs by default | No | Yes, if selected |
| Add/Remove Programs entry | No | Yes |
If you are just trying StealthPDF, run the portable EXE. If you use it regularly, click Install for shortcuts, file association, and clean uninstall support.
- Windows 10 or Windows 11, x64.
- No separate runtime install for normal use. The app targets .NET Framework 4.8, which is present on supported Windows releases.
- Get the app from the website: stealthpdf.com — the downloadable build (portable EXE / per-user installer) is hosted there.
- GitHub hosts the source code (and release archives for packagers): https://github.com/aabhpsy/StealthPDF
- Also on package managers:
choco install stealthpdf·winget install aabhpsy.StealthPDF
git clone https://github.com/aabhpsy/StealthPDF.git
cd StealthPDF
dotnet build KillerPDF/StealthPDF.csproj -c ReleaseFor a publish bundle with the single bundled EXE and GPL source zip:
dotnet publish KillerPDF/StealthPDF.csproj -c ReleaseOutput lands in KillerPDF/bin/Release/net48/publish/. Building requires the .NET SDK even though the app output targets .NET Framework 4.8.
Some internal folders still use the historical KillerPDF path for git-history continuity. The shipped application, executable, registry entries, file associations, and user-facing branding are StealthPDF.
- Original project: KillerPDF by Steve the Killer.
- Fork/rebrand maintainer: @aabhpsy.
- Engines and libraries include PDFium, Tesseract OCR, PdfSharpCore, PdfPig, Docnet.Core, NTwain, and PyMuPDF.
See CHANGELOG.md.
GPLv3. See LICENSE. StealthPDF is a GPLv3 fork/rebrand; forks, modifications, and redistributions must also provide GPLv3 source.