Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.ASCII GRID
File Type
ASCII Grid
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .ascii grid file format
The ASCII Grid file format (.asc) is a plain text raster data format commonly used for representing spatial data, particularly elevation models, terrain data, and other gridded datasets. It stores data as a grid of values, where each value represents a measurement or attribute associated with a spe…
File extension
.ASCII GRID
File type
ASCII Grid
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .ascii grid file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .ascii grid.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .ascii grid file?
File extension details and usage information
The ASCII Grid file format (.asc) is a plain text raster data format commonly used for representing spatial data, particularly elevation models, terrain data, and other gridded datasets. It stores data as a grid of values, where each value represents a measurement or attribute associated with a specific cell in the grid. The file typically begins with a header section containing metadata about the grid, such as the number of rows and columns, the cell size (resolution), the coordinates of the lower-left corner of the grid, and a 'nodata' value that indicates missing or invalid data. Following the header, the file contains the actual data values, arranged in rows and columns. The values are typically numeric and separated by spaces or other delimiters. ASCII Grid files are human-readable and relatively simple to create and edit, making them a popular choice for data exchange and storage in various geographic information systems (GIS) and remote sensing applications. They are often used as an intermediate format for converting data between different GIS software packages or for storing data in a format that can be easily processed by custom scripts and algorithms. The simplicity of the format makes it accessible for both beginners and experienced users in the geospatial field.
Software Compatibility
Programs that may open or work with .ascii grid files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .ascii grid files be converted?
Options for saving or exporting this file to another format
In many cases, a .ascii grid file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .ascii grid file.
Why can't I open a .ascii grid file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .ascii grid format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .ascii grid files
To open a .ascii grid file, use software that supports this file format.
- ArcGIS Pro
- QGIS
- Global Mapper
- ENVI
- Golden Software Surfer
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .ascii grid file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.