Quick access to a document matters most when the software that made it is on somebody else's machine. The Online Document Viewer opens the file in a browser tab instead. Here is what it covers, what the limits are, and what it leaves to other tools.

Key features

1. Multi-format support
70+ extensions, including:

PDF — read it in the tab, no Acrobat.
Microsoft Office (Word, Excel, PowerPoint) — rendered, not edited. Formula cells show their results; macros are never run.
CAD (DWG, DXF, DGN) — layers switch off one at a time, no AutoCAD licence.
Images (PSD, SVG, TIFF and the common formats) — including the Photoshop composite, without Photoshop.
Email (EML, MSG, EMLX) — body, headers and attachments, each attachment viewable on its own.
Plus Visio, Project, EPUB, HTML, XML and text.

2. Fast, and nothing kept
Transfers run over HTTPS. Documents are not stored: the file is deleted after viewing. No installation, no sign-up. Rendering happens on the server, which does mean the server reads the file while it draws it.

3. Reading controls

Zoom and page navigation, with slide navigation for presentations.
Search over the text a document already carries. A scanned page holds pixels rather than characters, and there is no OCR here, so it returns nothing.
Print from the browser.
No editing, no annotation layer, no signing.

4. Any device
Desktop, tablet or phone. The server does the rendering, so an old machine is not a problem.

5. File size limits, one per format
25 MB for PDF, PSD, Visio, EPUB, TIFF and images; 20 MB for Excel, PowerPoint and Project; 15 MB for Word and RTF; 10 MB for CAD and email; 5 MB for HTML, XML and plain text. Over the ceiling the upload is refused and the message names the number.

6. Conversion, when reading is not enough
PDF to Word, Excel, PowerPoint, PNG or JPG. Word and Excel to PDF or image. Images to PDF, WebP or TIFF. One file per conversion, on the converter pages.

Who it suits

Professionals who need a file open now, without an install or a licence request.
Students opening coursework in whatever format it arrived in.
Legal and financial staff who want the file to leave no trace afterwards — with the caveat that a hosted viewer is still a server reading your document. If it may not leave your network, the Doconut SDK runs inside your own infrastructure.

Key takeaways

70+ extensions, from PDF and Office to CAD, PSD, email and EPUB.
No installation, no account, no fee.
The file is deleted after viewing; there is no library, no sharing and no audit trail.
Reading and printing, not editing or annotating.
Size limits are per format, not per site.

Open a file at the Online Document Viewer. Free, and nothing to sign.