Open Source PDF Editor
PDF editing is a category held together by a single file format, not by a single task. In practice, editing a PDF means one of several different jobs: shuffling and merging pages, marking up a document with a pen or highlighter, making a scan searchable with OCR, or generating a polished PDF from scratch. Very few tools rewrite the text inside an existing PDF cleanly, because the format was designed to be final. Open source matters here because the sensitive work - signing a contract, redacting an ID, OCR-ing medical records - can run entirely on your own machine, so a confidential page never makes a round trip through a stranger's server.
Stirling PDF
Self-hosted PDF platform with 50+ tools, a browser UI, and a private API
OCRmyPDF
Command-line OCR for scanned PDFs that adds a searchable text layer and keeps the original images intact
Xournal++
Handwriting note-taking and PDF annotation app with pressure-sensitive pen support
Sioyek
Keyboard-driven PDF viewer built for reading textbooks and research papers
ONLYOFFICE Docs
Collaborative online office suite for documents, spreadsheets, presentations, forms, PDFs, and diagrams
PDF Arranger
Small GTK app to merge, split, rotate, crop, and rearrange PDF pages
PDFsam
Desktop PDF tool for splitting, merging, mixing, rotating, and extracting pages
Paged.js
JavaScript library for paginated browser layouts and print book PDFs using HTML and CSS
Okular
Document viewer that opens and annotates PDF, PostScript, comics, EPUB, Markdown, and images
Our picks
Because no single tool does everything, pick by the job in front of you.
Best all-in-one PDF toolkit: Stirling PDF Stirling PDF bundles more than fifty operations - merge, split, OCR, compression, signing, redaction, and conversion - behind a browser interface you self-host. Because it processes files locally instead of sending them to an outside service, it keeps sensitive documents private, and REST APIs let you fold the same operations into your own systems.
Best for splitting and merging pages: PDFsam PDFsam Basic focuses on page-level work: splitting by page, size, or bookmarks, merging many files, mixing pages in alternating order, and extracting ranges. It runs entirely offline on Windows, macOS, and Linux and ships as a self-contained app, which makes it a dependable choice for repeatable batch tasks that never leave your desk.
Best for making scans searchable: OCRmyPDF OCRmyPDF adds a searchable text layer to scanned PDFs while preserving the original image resolution, so the page still reads as the scan but its text can be selected and searched. It outputs PDF/A for archiving, handles over a hundred languages through Tesseract, and scripts easily across large batches from the command line.
Best for stylus markup: Xournal++ Xournal++ is built for annotating PDFs by hand, with pressure-sensitive pen support for tablets like Wacom, plus highlighting, layers, and text tools. It exports back to PDF, SVG, and PNG and runs on Linux, Windows, macOS, and Android, making it a strong fit for reviewing or signing documents with a stylus.
Matching the tool to the job you actually have
Name the job before the tool, because PDF editor covers work that no single app does well. Page assembly - split, merge, rotate, reorder - is a distinct task handled cleanly by PDF Arranger or PDFsam, both of which run offline and never touch document content. Annotation and markup, especially with a stylus, is Xournal++ territory, while Okular adds native PDF annotations across many other formats. Scanned paper is a third job entirely: OCRmyPDF adds a searchable text layer while leaving the original images intact, which is exactly what legal and archival workflows need.
If you want one interface for most of it, Stirling PDF bundles more than fifty tools - merge, split, OCR, compression, signing, redaction, conversion - behind a browser UI you host yourself, and processes files locally rather than shipping them to an outside service. That local-processing point is the one to weigh most for sensitive documents. A local desktop app keeps files on your machine by default; a browser-based tool is only as private as where its rendering, OCR, and saving actually happen, so confirm that before you upload a contract or a scanned ID.
Generating PDFs is the opposite problem from editing them. For print books and precise page layout, Scribus is a full desktop publishing tool, while Vivliostyle and Paged.js turn HTML and CSS into paginated, print-ready output. Whatever the job, verify one thing about redaction before you rely on it: that it removes the underlying content instead of drawing a black box over it, and confirm that by searching and copying text in a separate viewer.
Related categories
Frequently asked questions
Can any of these actually edit the text inside a PDF?+
Only to a limited degree, because PDF is a final layout format, not a document. Text is often split into positioned fragments with subset fonts, so replacing a word of similar length may work while rewriting a paragraph often will not. Stirling PDF and ONLYOFFICE offer the most direct editing, but for heavy changes the reliable path is to edit the source document and regenerate the PDF.
I just need to merge, split, or reorder pages - what should I use?+
For page assembly without touching content, PDF Arranger gives you a visual drag-and-drop interface to merge, split, rotate, and rearrange pages, and can pull in images too. PDFsam handles the same operations plus alternating-page mixing and is well suited to batch jobs. Both run fully offline on Windows, macOS, and Linux, so documents never leave your machine.
How do I turn a scanned PDF into searchable text?+
OCRmyPDF is built for exactly this. It adds a hidden searchable text layer using Tesseract, supports more than a hundred languages, and keeps the original image resolution intact so the page still looks like the scan. It outputs PDF/A, which suits archives, and can deskew and clean pages on request. It runs on the command line, which makes it easy to batch across many documents.
Is redaction in an open source PDF editor actually safe?+
Only if the tool performs true redaction that removes the underlying objects, not a black rectangle laid over text that stays selectable and recoverable. Proper redaction should also strip metadata, annotations, and hidden layers. Stirling PDF includes a redaction tool among its set, but whatever you use, always verify the result by searching and copying text and inspecting the file in a separate viewer.
Which of these are best for marking up documents with a stylus?+
Xournal++ is the strongest choice for pen input: it supports pressure-sensitive tablets like Wacom, lets you write and highlight over a PDF, and exports to PDF, SVG, and PNG. Okular also adds native annotations and runs on desktop and Android if you want a lighter reader-plus-markup tool. For pure reading of long technical documents, Sioyek is keyboard-driven rather than annotation-focused.
Are browser-based PDF tools private?+
It depends entirely on where the processing runs. Many free web tools upload your file to a server to merge or OCR it, which is the exact risk you want to avoid with contracts or IDs. A self-hosted tool like Stirling PDF processes files on infrastructure you control, and desktop apps such as PDFsam or Xournal++ keep everything local. For sensitive work, confirm where rendering, OCR, and saving happen before uploading anything.
Can I create a print-ready PDF, not just edit one?+
Yes, and it is a different set of tools. Scribus is a full desktop publishing application for controlled page layout, typography, and print output, with strong support for complex scripts. If you prefer to work in HTML and CSS, Vivliostyle and Paged.js paginate web content into print books and export PDF, which suits documentation and book workflows more than a page editor would.