What is an APR file?
An .APR file can serve several different purposes depending on the software that created it. Most often, it is a database application file for legacy Lotus Approach software. It is also widely used as an ArcView Project File by ESRI for geographic information system (GIS) mapping. In other industries, .APR files act as Gerber aperture list files for printed circuit board design in Altium Designer.
How to open APR files?
Because the .APR extension applies to multiple completely different formats, you must know the file's origin to open it locally. An ArcView Project File requires ESRI ArcView GIS, while a Gerber aperture list opens in CAD software. viewer.online/apr analyzes .APR files to identify their exact format and creator software, shows which programs can open the file, and usually previews it.
Software and tools
You can open GIS-related .APR files with ESRI ArcGIS Pro. For Gerber lists, use Altium Designer or a free Gerber viewer. Some newer .APR files are actually ZIP or RAR archives containing presentations or construction estimates; you can use 7-Zip to extract their contents. Others are plain JSON text files readable in any text editor or developer tool.
Best practices and troubleshooting
If an .APR file does not open, do not rename the extension. Renaming does not change the internal format. First, identify the file type. You can use command-line tools like `file` on Linux or macOS to inspect the file header. If the file is an old Lotus Approach database, you might need a virtual machine running an older operating system to run the original software.
Summary
Do not guess the format of an unknown .APR file. Because .APR files use the known DOC, ZIP, RAR, or JSON formats, viewer.online/apr can safely open and display them online, eliminating compatibility problems. Whether it is an ArcView Project File from ESRI or a legacy database, viewer.online/apr will identify the actual format of your file securely.