Open NetCDF files in your browser
The file climate, weather and ocean data comes in, from ERA5 to CMIP models. Open one right here and see every variable, with no Python or Panoply. Nothing leaves your device.
Or drop it anywhere on this page
What you'll see
Your NetCDF file opens as its variables, each with its units and dimensions, and each variable opens as a table.
- Every variable • Its type, units and dimensions
- Dimensions • Their sizes, the unlimited one marked
- Global attributes • Conventions, source and history
- Each variable opens as a table • Saves as a NumPy array
About NetCDF
NetCDF is how climate and weather data is shared: Copernicus' ERA5, NOAA's and NASA's datasets, CMIP's climate models and ocean buoys all come as .nc files, mostly following the CF conventions, which say how to name units, times and coordinates.
A file has dimensions, like time, latitude and longitude, and variables laid out along them, each with attributes such as its units and long name. One dimension can be unlimited, so records are added over time. The classic format and its 64-bit versions keep everything in one layout of their own, and NetCDF-4 keeps it in HDF5.
Filepeek reads every kind in your browser. The card lists the variables with their type, units and dimensions, the dimensions with their sizes and the global attributes, and each variable opens as a table and saves as a NumPy array. Values show as they're stored, before any scale factor or offset.
Network Common Data Form
.nc4
Format
- MIME type
- application/x-netcdf
- Made by
- Unidata
Inside the file
- Holds
- Variables along named dimensions
- Kinds
- Classic, 64-bit and NetCDF-4
- Conventions
- CF, for units, times and grids
- NetCDF-4
- Kept in HDF5
Opens in every browser
Browsers download NetCDF files. Filepeek opens classic, 64-bit and NetCDF-4 files in Chrome, Edge, Firefox and Safari.
- YouChromeOpens through Filepeek
- YouEdgeOpens through Filepeek
- YouFirefoxOpens through Filepeek
- YouSafariOpens through Filepeek
Apps that open NetCDF
- WindowsPanoply, free • ncdump from Unidata
- MacPanoply, free • ncdump from Unidata
- iPhone and iPadNo app opens it
- AndroidNo app opens it
Questions
How do I open a .nc file?
Drop it on this page or choose Peek a NetCDF. Every variable shows with its units and dimensions, with nothing to install.
Can I convert NetCDF to CSV or Excel?
Yes. Open a variable from Arrays, then choose Export and Save as CSV, Excel, JSON or Parquet. A variable over time, latitude and longitude opens with a row for each time and latitude, and a column for each longitude.
Why do some values look like 9.97e+36 or -32767?
Those mark places with no data, as the variable's _FillValue or missing_value attribute says. Packed variables keep whole numbers too, which become real values once multiplied by scale_factor and added to add_offset. Filepeek shows values as they're stored, and both attributes in the Tree.
What does 'NetCDF: Unknown file format' mean?
The file isn't one NetCDF reads: often a GRIB file or an HDF4 file named .nc, or a web page a download saved instead of the data. Filepeek says so too, and a web page opens as text.
Is my .nc file data or a CNC program?
Both are named .nc. Filepeek tells them apart by their first bytes, so NetCDF data opens as its variables and a CNC program as its toolpath.