Core local editing: Most online PDF sites work by uploading your file to their server, processing it there, and letting you download the result. This editor does not have a server for your files: the OnlyOffice PDF engine is compiled to WebAssembly and runs inside your browser tab. When you pick a file it is read straight from disk into memory — there is no upload step and no server round-trip — so confidential PDFs stay on your machine.
You can scroll, zoom and search the document, add comments and free-text annotations on top of the page, and save it back as a PDF that keeps those annotations. Because PDF is a fixed-layout format the body text is not rewritten like a Word document; if you need to change the wording, open the original DOCX, XLSX or PPTX here and export a fresh PDF from it — also on your device.
How it works
- Click Open your PDF to launch the editor in your browser.
- Pick a .pdf file from your device, or drag and drop it onto the page.
- It renders locally with the OnlyOffice PDF engine — read it, search it, add comments and annotations.
- Download it again as PDF when you are done; your annotations are merged into the file locally.
What you can do
- Open and read any .pdf file — text, scans, forms, multi-page reports
- Add comments and free-text annotations, then save back as PDF
- Create a PDF from a DOCX, XLSX or PPTX with Download as PDF
- No Adobe Acrobat, no Reader, no account, no Copilot
- Core local editing: No upload — your PDF never leaves your device
- Cached editing resources can work offline; remote file URLs need a connection.
Frequently asked questions
Can I open a PDF without Adobe Acrobat?
Yes. It opens PDF directly in your browser with the OnlyOffice PDF engine — no Acrobat, Reader or account.
Is my PDF uploaded anywhere?
Core opening, editing and conversion run locally in your browser without a required document upload. The built-in AI assistant is unfinished and is not a released feature. An embedding host can receive exported files and upload them according to its own policy.
Can I annotate the PDF, not just read it?
Yes. Add comments and free-text annotations, then save back as a PDF that keeps them.
Can I rewrite the text of an existing PDF like a Word document?
Not as free-flowing text — PDF is fixed-layout. Read, comment and annotate here; to change wording, open the original DOCX/XLSX and export a new PDF from it.
Can I create a PDF from a Word or Excel file here?
Yes. Open the DOCX, XLSX or PPTX and choose Download as PDF — the PDF is generated on your device.
Does it work offline?
Offline editing requires the application, editor engine, converter and relevant fonts and format resources to be cached and retained by your browser. One visit or PWA installation does not guarantee this. Remote file URLs require a network connection.
Is there a file size limit?
No fixed limit. Everything runs in your browser, so the practical ceiling is your device's memory.