Universal Document Viewer
Open any supported document — the right viewer is picked for you.
About Universal Document Viewer
Drop in a PDF, Word, Excel, PowerPoint, CSV, Markdown, JSON, XML, HTML or text file and Office Utilities picks the right viewer from the file’s extension. What each viewer offers differs — the PDF reader has search, zoom, thumbnails, fullscreen and print; the others have the controls that suit their format — and nothing is uploaded.
The everyday problem is not opening one format, it is not knowing which format you have been sent — and having a different tool bookmarked for each one.
Drop in almost any document and it opens in the right reader.
- Processed on your deviceEverything you open or type here is handled by this page and never uploaded anywhere.
- No queue, no limitsNothing waits on a server, so the only limit is your own hardware.
- No account neededNo sign-up and no email address required.
How Universal Document Viewer works in your browser
The viewer is chosen from the file’s extension, falling back to the type the browser reports when the extension is unknown, and the matching reader is loaded on demand: PDF.js for PDFs, Mammoth for Word, SheetJS for spreadsheets, a direct OpenXML parser for PowerPoint, and dedicated readers for CSV, Markdown, JSON, XML, HTML and plain text.
That means a mislabelled file opens in the wrong viewer: a PDF saved with a .txt extension is shown as text. If something looks like nonsense, run it through the File Signature Checker, which reads the bytes and tells you what the file really is, then rename it.
Only the reader you need is downloaded. Opening a Markdown file does not fetch the PDF engine, which is why the page stays light despite handling a dozen formats.
When to use it
Opening an attachment when you are not sure what it is. Reading documents on a device with no office software installed. Checking a file from an unfamiliar sender in a browser tab rather than in desktop software. Reading a confidential document without uploading it to a web viewer.
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Frequently asked questions
Are my documents uploaded to a server?
No. Every viewer runs as JavaScript and WebAssembly inside your browser tab. The file is read from your disk by the page itself and never crosses the network.
How large a file can I open?
The practical limit is your available memory. PDFs of a few hundred megabytes generally work, because PDF.js parses in a Web Worker and renders pages on demand. Word, Excel and PowerPoint files are parsed on the main thread, so a very large one can make the page pause while it opens.