When it comes to CAD files, professionals often face a common challenge: how to view and share these detailed and complex drawings across different devices without specialized software. Whether you're working with DWG, DGN, or DXF files, these formats can require high-end programs like AutoCAD or MicroStation, making it difficult to share or access them quickly.
The CAD viewer at OnlineDocumentViewer.com takes DWG, DXF and DGN, up to 10 MB per drawing. No AutoCAD, no MicroStation, no plugin, no account. The file is deleted from the server afterwards.
Three formats, three origins
- DWG — Autodesk's native drawing format. Binary and closed.
- DXF — the published text interchange version of the same drawing. Larger, readable by far more software, and the file to ask for when a DWG fails.
- DGN — MicroStation, from Bentley. Standard on civil, infrastructure and utilities projects.
All three open here, on a laptop, a tablet or a phone. The viewer is a web page, so the operating system stops mattering — which is the point when a drawing has to be read on site.
No Software, No Plugins—Just a Browser
Traditional CAD viewers mean a purchase and an install. Here it is a web page: OnlineDocumentViewer.com renders the drawing on the server and sends your browser the result.
What renders, and what you can do with it
Powered by the Doconut .NET Library, the drawing is rendered from the drawing data rather than from the preview thumbnail stored inside the file. That matters: a thumbnail is a low-resolution snapshot, and a title block read from one is illegible.
- Layer control: switch individual layers off to read a crowded plan — hide the hatching or the services layer and read the walls underneath.
- Measurement: take distance, angle and area on the open drawing.
- Vector rendering: line weights, hatches and dimension text stay accurate at every zoom level, and title blocks stay legible at full zoom.
- Multi-sheet files: open a sheet at a time.
What it does not do: it renders, it does not edit. Nothing here moves a line, changes a dimension or saves a revision.
What happens to the drawing
Be exact about this, because design files are usually somebody's intellectual property:
- Nothing is stored. The drawing is uploaded over TLS, rendered on the server, and deleted when the session ends. There is no account, no library and no second copy.
- No permissions, because there are no users. This is a public website: no role model, no sharing control and no audit trail. There is no link to your open drawing either — the upload belongs to one session and is deleted when it ends.
- Nothing runs on your machine. The browser receives rendered pages, not the DWG, so no CAD software and no plugin is involved at your end.
If a drawing may not leave your network at all, a hosted viewer is the wrong shape of tool — this one included. The Doconut .NET Library is the version that runs on your own servers.
When a drawing will not open
Over 10 MB. PURGE unused blocks, layers and styles first — it often halves the file. Then AUDIT, then -WBLOCK out only the objects you need. Do not convert to DXF to shrink it: DXF of the same drawing is bigger.
Blank, or nearly. Usually layers switched off or frozen, or you are looking at model space when the content is in a paper space layout.
Sparse, with pieces missing. Xrefs, SHX fonts and .ctb plot styles are separate files on the sender's machine. Ask for the whole folder, or for a bound copy.
Conclusion
DWG, DXF and DGN, up to 10 MB, in a browser tab, with layers and measurement. Free, no account, deleted afterwards. To hand a drawing to someone with no CAD software at all, the CAD converter turns DWG and DXF into PDF at up to 5 MB.
Open the CAD viewer and drop a drawing on it.