Format → format, with a loss forecast
Transform and convert CAD and GIS data, and see up front what will change
Works both ways between GeoPackage, MapInfo TAB, Shapefile, AutoCAD DXF, GeoJSON, KML and other formats. DWG is read-only. You see what will be lost before anything is written, and we verify the file after.
For engineers, designers, surveyors and GIS specialists.
Swage is in beta. When the server is busy, jobs wait in a queue. If something doesn't work as it should, please tell us.
Anyone can sign up with an email address. Type it on the sign-in page, press the button in the letter and convert your own files on our server.
Example: Roads_CAD.dwg, a road network of 7152 features in 9 layers. The coordinate system turned up in the drawing's own text
We read DWG, AutoCAD DXF, GeoPackage, MapInfo TAB, Shapefile, GML, CSV, SQLite, FlatGeobuf, GeoJSON, KML, Polish MP, File Geodatabase, MapInfo MIF, GPX, XLSX, ODS, KMZ, KMZ (doc.kml) and a ZIP archive with such files
Pick a format and see what happens to the file
- GeoPackage: all 7152 of 7152 will be written and verified
- MapInfo TAB: elevation will be lost for 3355 of 7152
We read the source file and count what's in it. Once the job is done, we delete it.
The converter runs in a browser, on a computer or a phone, with nothing to install. On a phone we have walked the whole path from upload to result, in portrait and in landscape.
on Roads_CAD.dwg
The other direction works too. Writing to AutoCAD DXF kept all 30 of 30 features.
How it works
Simple view or engineering view, one converter
In the simple view you upload a file, pick a format and get the result. The engineering view adds a pipeline, where you can rename, merge or filter layers.
Simple
Three steps for a one-off job.
File
Upload a drawing or a table, a whole folder of them, or a ZIP archive.
Format
Pick the format and see the loss forecast right away.
Result
We write the file, open it again and compare it with the source. Then you get the "Verified" or "Verified with losses" seal and the feature count.
Engineering
File → pipeline → format → result. In the pipeline you decide what happens to each layer.
File
Upload a drawing or a table, a whole folder of them, or a ZIP archive.
Pipeline
Merge, filter or rename layers. Or leave them as is.
Format
Pick the format and see the loss forecast right away.
Result
We write the file, open it again and compare it with the source. Then you get the "Verified" or "Verified with losses" seal and the feature count.
Every step of this job with its numbers, the way the converter shows them
Formats
Formats we read and write
The bigger the name, the more often people need the format. Each name opens its row in the full list, where you can see what the format keeps and what it loses.
GISCADweb, exchange and tablesAll formats (19)
- Shapefileclassic Esri GIS layer
- GeoPackageopen GIS file, many layers
- MapInfo TABMapInfo Pro tables
- File GeodatabaseArcGIS database in a folder
- FlatGeobuffast file for large layers
- SQLiteSQL database in one file
- MapInfo MIFMapInfo as plain text
- Open this group in the full list
- DWGAutoCAD drawings, read only
- AutoCAD DXFopen drawing for CAD exchange
- Open this group in the full list
- GeoJSONweb maps and APIs
- KMLmaps for Google Earth
- GMLOGC XML for data exchange
- GPXGPS tracks and waypoints
- KMZzipped KML, GDAL reads its fields
- KMZ (doc.kml)zipped KML, no height added
- Polish MPsource for Garmin maps
- Open this group in the full list
- CSVplain table, geometry as text
- XLSXExcel sheets, points as X and Y
- ODSLibreOffice sheets, points as X and Y
- Open this group in the full list
Verification
We read every file back
We put the "Verified" seal on screen only after we've read the written file and compared it with the source feature by feature.
Verified
Everything matched. We've already read back the file you're about to download and compared it with the source
Verified with losses
Only what we warned you about differs: elevation removed from 3355 of 7152
Didn't match
Something differs that we didn't warn you about. That means the mistake is ours. The format has nothing to do with it
How we verify
What "verified" stands for
Once the result is written, we open it again and compare it with the source file feature by feature. A file that merely opens isn't enough for us.
What we compare
- How many features went in and how many came out
- A digest of each feature's geometry and its vertex count
- How far the coordinates moved (up to 0.05 m is allowed)
- Field types and values
- The coordinate reference system (CRS)
What may differ
- Only what we named before writing, for example "elevation removed from 3355 of 7152"
- And the number has to match what we find in the finished file
What verification doesn't cover
- Line styles and colors
- The meaning of blocks and the drawing's sheets
- If the geometry is too big for a detailed check, we hand over the file marked "Written N of N, the detailed check was not done"
The engineering view
How data moves from layers through processes to formats
The thicker the line, the more features run along it. The line to MapInfo TAB shows a loss we warned you about before writing.
Coordinate systems
What happens to coordinates and elevation
And where the report tells you about it.
- We take the coordinate system from the file or from your choice at upload. If neither has one, we look for indirect clues, such as text in the drawing. A CRS found that way is marked as a guess and stays out of the result until you confirm it
- If the coordinates are in degrees, we convert the shift to meters at the feature's own latitude
- If the format can't hold elevation, you see before writing how many features it is removed from: "elevation removed from 3355 of 7152"
- The report gives the coordinate shift after writing in meters. Up to 0.05 m is fine. If the shift is larger, there is no "Verified" seal, and the report says why
- If you need the result in another coordinate system, we reproject every feature at once. The report then has a line like EPSG:XXXX to EPSG:YYYY
Examples
Real files from different sources
These are real files that went through Swage.
Data and trust
What happens to your file
- We delete the source file as soon as we no longer need it
- We write the result from our internal copy of the data. The link works for 24 hours, then the files are deleted within the hour
- We don't pass the source file or anything made from it to anyone, apart from the technical providers named in the policy
What we tell you in advance
- On our test files, reading and the forecast take about 30 s for Roads_CAD.dwg (7152 features) and about 5 min for a sewer network (72,726 features)
- If a format can't keep something, you'll find out when you choose it
In numbers
What Swage has processed so far
Counted on the jobs people ran on Swage since counting began. Our own test runs are not counted.
Most asked conversions, in jobs
We keep only daily sums: no file, no file name, no job number and no address. A conversion fewer than 5 jobs asked for is not named.
FAQ
Frequently asked questions
How do I convert DWG to GeoPackage online?
Upload a DWG or a ZIP archive and choose GeoPackage. The loss forecast shows up right away, and most of the time it's zero. We do the rest: write the file and verify it against the source.
Can I convert DWG to MapInfo TAB without AutoCAD?
Yes. We read DWG ourselves, no AutoCAD needed. Just keep in mind that MapInfo TAB doesn't store elevation: on Roads_CAD.dwg from the example above it is removed from 3355 of 7152 features. You see that number before writing.
Why does elevation disappear when writing to MapInfo TAB?
The format simply has no place for it. We measured this on a real file and show you the number before writing.
Does Shapefile store elevation?
Yes, with a catch. A Shapefile layer is either all 3D or all flat. If one layer mixes features with and without elevation, Shapefile itself writes Z = 0 to the flat ones, and that zero can't be told from a real height. We don't make up elevation, so we write such a layer without it. You get the count in advance: on Roads_CAD elevation is removed from 10 features.
Why is a layer name in DXF/DWG sometimes "wrong"?
Nobody keeps CAD layer names consistent. Road, Roads and ROAD can be three different layers in one file. We show them exactly as they are written.
What happens to the coordinate reference system if the file doesn't have one?
We won't make one up. We look for clues in the drawing itself, like text or the coordinate range. A system found that way is labeled as found by heuristic, so nobody takes it for a set one. In Roads_CAD.dwg the clue was ordinary text on the drawing.
What happens to long text and labels?
In Shapefile and MapInfo a string can hold 254 bytes in the chosen encoding. A Cyrillic letter takes 2 bytes and a space takes 1, so a 200-character Cyrillic string with spaces comes back 139 characters long.
Does the file stay with you after conversion?
No. We delete the source file when the job is done. The result's link works for 24 hours, and within an hour after that we delete those files too. We pass nothing to anyone except the technical providers named in the privacy policy.
What does the "verified with losses" seal mean?
Everything matched except the losses we named before writing, and those matched the number we gave.
Does this work with ZIP archives or folders of MapInfo/Shapefile?
Yes. Both formats are made of several files (.tab+.dat+.map+.id, .shp+.shx+.dbf+.prj). We find the ones that belong together in the archive or the folder and tell you which we took. Pictures, rasters and other programs' files in a folder stay on your computer, and we name them too.
Who decides what a layer means (road, building, water)?
That's a separate experiment on top of the converter, and you can check its results. The conversion itself uses no AI. The model only suggests a name from a closed dictionary and never touches geometry.
Can I get DWG as output?
No, we only read DWG. You can write to MapInfo TAB, Shapefile, GeoPackage, GML, KML, FlatGeobuf, SQLite, CSV, GeoJSON, AutoCAD DXF, Polish MP, File Geodatabase, MapInfo MIF, GPX, XLSX, ODS, KMZ and KMZ (doc.kml). A GIS layer can go to DXF too, and a table to a spreadsheet.
Can I convert DWG to Shapefile without AutoCAD?
Yes. We read DWG ourselves and write Shapefile straight from it. There's one catch: a Shapefile layer is either all 3D or all flat. If only some features in a layer have elevation, the layer is written without it. On Roads_CAD.dwg that removes elevation from 10 features, and you see that number before writing.
News
What's already done
Newest first.
October 2026
- Layers from different files no longer merge on their own: as many layers go in, as many come out. You can merge them with one button on the Pipeline step.
- You can now pick a whole folder. We take the files in formats we read, leave the rest on your computer and show you the list.
- We added MapInfo MIF/MID for input and output, and writing to GPX. GPX points become waypoints, lines become routes and tracks.
- Swage now reads and writes ArcGIS File Geodatabase. You can upload a geodatabase as a zip or as a folder. Whatever does not carry over, we name as a number before writing.
- Every job page has a link, "Something wrong with this job? Tell us". It sends us the job and the details of your browser, so you don't have to describe them.
- Polish MP files, the text format behind many Garmin community maps, now open in Swage, and you can write your data out as MP too. Anything the format can't hold is listed before writing.
- Once the result is ready, you can change your mind and write it again: rename a layer, turn off one you don't need or pick another format. Earlier versions stay where they are.
- You can now pick your emails at upload, for example just one when the result is ready.
- If we couldn't process a file, we tell you why and show what in it got in the way.
- If only part of a large file could be verified feature by feature, we say so and show how much was verified.
- A hatch made of several parts now becomes one polygon per part. Before, it came out as a single polygon with the other parts as holes. GML fields written straight into the tags now reach the result too.
- You can follow a job live on its page. If you allow notifications, the browser tells you when it's done.
- Cyrillic, Chinese, Arabic and Hebrew in layer names and labels now reach the result intact. If a format can't store some character, we tell you before writing.
- If a large file can't be verified in detail, you still get the result. It comes with a mark and the number of features that matched.
- You can now write several tables into one DXF file, and each becomes its own drawing layer.
- Merging layers no longer loses a coordinate system that has no EPSG code.
September 2026
- You can download the conversion report as a PDF.
- The "Verified" seal now appears on the result.
- We started verifying the result against the source file feature by feature.
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About
Why Swage
Swage is made by engineers who spent years moving data between CAD and GIS and know where it breaks along the way. That's why we name the losses up front and verify every result before it reaches you.