Convert DXF to FlatGeobuf Online — Free GIS Converter

FlatGeobuf is the fastest binary vector format for cloud-native GIS — convert your .dxf CAD drawing to .fgb for high-performance spatial queries, HTTP range streaming, and GDAL-based pipelines with geodata.plus.

Why convert DXF to FlatGeobuf?

Once a DXF drawing has been cleaned up, attributed, and is ready for production use in a GIS pipeline, FlatGeobuf is an excellent storage format. Its binary columnar layout with a built-in spatial index enables extremely fast spatial queries without loading the entire dataset into memory — critical when working with large engineering drawings that may contain hundreds of thousands of vertices.

FlatGeobuf also supports HTTP range requests, meaning the file can be hosted on any static file server or S3-compatible object store and queried spatially by clients without downloading the whole file. For organizations building cloud-native spatial data pipelines from CAD inputs, DXF-to-FlatGeobuf is a natural step.

Why use geodata.plus

• Free tier — convert up to 3 files per month at no cost, no credit card required
• Automatic CRS detection — reads coordinate hints from the DXF header and lets you assign the correct source EPSG before conversion
• Optional reprojection — reproject to any target EPSG code before download
• Browser-based — no QGIS, GDAL, or AutoCAD install needed; works on any modern browser
• Encrypted transfer — all uploads use TLS; files are stored temporarily in Cloudflare R2 and automatically deleted on schedule
• Auto-deleted output — output files are automatically deleted after 2 days (free tier) and 7 days (Pro); no manual cleanup needed

How it works

1. Upload your DXF file (.dxf) using the widget above
2. geodata.plus parses the DXF layer and entity structure, grouping by geometry type
3. Select FlatGeobuf as the output format; assign the source CRS and optionally reproject to a target EPSG
4. Download your .fgb file with a built-in spatial index ready for GDAL, Mapbox, or cloud storage

DXF format

DXF (Drawing Exchange Format) is Autodesk's open CAD interchange format. Geometry is organized as named layers of entities — lines, polylines, points, arcs, and polygon hatches. DXF has no native CRS; the coordinate space is set by the CAD project. It is the primary exchange format for engineering drawings, surveying deliverables, and infrastructure design files worldwide.

| Property | Value | |---|---| | Extension | .dxf | | Type | Vector, single file | | Coordinate system | None native — local/project coordinates assumed | | Geometry types | Points, Lines, Polylines, Arcs, Circles, Polygons (hatches) | | Common software | AutoCAD, Civil 3D, MicroStation, BricsCAD, surveying tools |

FlatGeobuf format

FlatGeobuf is a binary, row-oriented vector format built on the FlatBuffers serialization library. It stores a packed spatial index (Hilbert R-tree) at the start of the file, enabling efficient bounding-box queries via HTTP range requests without reading the full dataset. FlatGeobuf supports any CRS, all OGC geometry types, and arbitrary attribute schemas. It is supported by GDAL (1.0+), Mapbox, and a growing ecosystem of cloud-native GIS tools.

| Property | Value | |---|---| | Extension | .fgb | | Type | Vector, single file (binary) | | Coordinate system | Any CRS | | Geometry types | Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, GeometryCollection | | Common software | GDAL, QGIS, Mapbox, cloud-native GIS, web APIs |

Frequently asked questions

Can I query the FlatGeobuf output spatially without downloading the entire file?

Yes. FlatGeobuf's built-in Hilbert R-tree index supports HTTP range request queries, so tools like GDAL's /vsicurl/ virtual filesystem, Mapbox's PMTiles tools, and custom web clients can fetch only the features that intersect a given bounding box. This makes it ideal for serving large converted DXF datasets from S3 or any static CDN.

How does FlatGeobuf handle the mixed geometry types that often appear in DXF files?

A single FlatGeobuf file supports only one geometry type per file (similar to Shapefile). geodata.plus outputs separate .fgb files per geometry type from the DXF source and packages them in a ZIP archive. Each file is independently indexable and streamable.

Is FlatGeobuf supported in QGIS and ArcGIS Pro?

QGIS supports FlatGeobuf natively from version 3.16 onwards via its GDAL integration. ArcGIS Pro supports it through the GDAL/OGR driver available in recent releases. Both applications can open .fgb files directly by dragging them onto the canvas or using the Add Layer dialog.