Open files in VS Code and Cursor / Science data

Open an HDF5 (.h5) file in VS Code

Install the free NetCDF Viewer & HDF5 Viewer extension and click the .h5 file. Groups and datasets show as a tree. Click a dataset to see its type, shape, chunks and compression, its values as a table, and 2D data as a heatmap. Compressed data (LZF, Blosc, bitshuffle, Zstd, LZ4, bzip2, ZFP) opens without Python or h5py.

Install in VS Code Marketplace page Open VSX (Cursor, Windsurf, VSCodium)

Free, MIT license. Extension ID zovo.hdf5-netcdf-explorer, version 0.4.0. Needs VS Code 1.90.0 or newer.

beamline-scan.h5 with the group tree on the left and /entry/instrument/detector/image selected: a uint16 256 x 256 dataset with gzip compression, drawn as a heatmap with its min, max, mean and std.

Steps in VS Code

Install NetCDF Viewer & HDF5 Viewer from the Marketplace, or press Ctrl+P (Cmd+P on macOS) and run ext install zovo.hdf5-netcdf-explorer.
Click a .h5, .hdf5 or .he5 file. Also .nxs, .h5ad, .jld2 and .loom.
Pick a dataset in the tree. Switch between Table and Plot, and pick which dimensions are rows and columns.
Click "Copy h5py code" to get the Python line that reads the same dataset.
For a MATLAB v7.3 .mat file, right-click it and pick "Open in HDF5 NetCDF Explorer".

Steps in Cursor, Windsurf or VSCodium

Open the Extensions view with Ctrl+Shift+X (Cmd+Shift+X on macOS).
Search for zovo.hdf5-netcdf-explorer and click Install. Cursor, Windsurf and VSCodium install from Open VSX, where it is published as zovo/hdf5-netcdf-explorer.
If your editor has no gallery, download the .vsix from the Open VSX page and run "Extensions: Install from VSIX...".
Then use it the same way as in VS Code.

What NetCDF Viewer & HDF5 Viewer handles

Stats for each dataset: min, max, mean, std, and counts of fill, NaN and Inf values.
RGB and RGBA images drawn as pictures.
In the README test, a 37 GB array opened and drew a sampled heatmap in about one second.

What it does not do

HDF4 files are not supported. Rarer filters such as SZ show a message instead of values.
MATLAB v5 .mat files are not HDF5. Re-save them with -v7.3.
It's a viewer. It never writes to the file.

Other options

HDF5 Preview (lochbrunner.vscode-hdf5-viewer, 50,933 installs, not on Open VSX). Its own description: "Displays HDF5 files in VS code". Not on Open VSX, so not in Cursor.
HDFView. The desktop app from The HDF Group. It can also edit.
h5ls and h5dump. The HDF5 command line tools print the structure and values.

Install counts and Open VSX status were checked on 8 November 2026. Descriptions in quotes are the extensions' own.

Questions

Do I need h5py?

No. The extension reads HDF5 with a WebAssembly build of the library, so nothing else has to be installed.

Can I open NetCDF-4 files too?

Yes. NetCDF-4 files are HDF5 underneath, and the extension also decodes the NetCDF conventions. See the NetCDF guide.

Does it work over Remote SSH?

Yes, and in WSL and dev containers.

More about NetCDF Viewer & HDF5 Viewer

Read the NetCDF Viewer & HDF5 Viewer page for every feature and setting, or the source code on GitHub.

Support this work

If this extension saves you time, you can support the work on GitHub Sponsors. Monthly tiers start at $5, and one-time tiers start at $15. Sponsorship is optional, and the tool works the same without it.

Zovo on GitHub