What the converter draws
Drop a DXF and the page reads every entity in model space and reduces it to flat line work. Lines, polylines (including arc segments stored as bulges), circles, arcs and ellipses come through as you would expect. Splines are drawn through their control or fit points, which is close for gentle curves and a little angular for tight ones. Single-line TEXT and multi-line MTEXT are placed at their insertion point in Helvetica at the drawing's text height, with MTEXT formatting codes stripped. Blocks inserted with INSERT are expanded with their position, scale and rotation, so title blocks, symbols and repeated details appear where the drawing put them. The result is one PDF page containing the whole drawing in black 0.5pt lines, which is what most people need when they want to email a plan, attach it to a quote, or print it from a machine without CAD software.
What it skips
Anything that is not plain geometry is left out and listed in the Skipped count after you choose a file. That includes dimensions, hatches, leaders, points, solids, 3D faces, images and proxy objects. Layer visibility, colours, lineweights and dashed linetypes are ignored, so frozen layers still print and every line is the same weight. Paper-space layouts and viewports are not rendered; only model space is drawn. If the Skipped count is high and the polyline count is low, the drawing probably relies on hatches or dimensions for its content, and a plot from the CAD program will serve you better.
Scaling and page size
The drawing is scaled uniformly so its full extent fits inside a half-inch margin on the page you pick, Letter or A4, landscape or portrait. Proportions are always preserved and nothing is cropped. There is no fixed plot scale such as 1:50; if you need a true-scale print, use your CAD program's plot dialog instead. Text is scaled with the geometry, so labels on a large site plan can become tiny on a single page. Drawings with a stray entity far from the rest will come out small, because the extent includes that stray; erase it in CAD and reconvert.
Privacy
The file is read with the open-source dxf-parser library and the PDF is written with pdf-lib, both running inside your browser tab. No part of the drawing is transmitted, logged or stored, and there is no account. The only thing we record is an anonymous event that the tool was used, so we know which tools are worth maintaining.