NPY Viewer | Open NumPy NPY & NPZ Files Online

NPY viewer that opens NumPy .npy and .npz files in your browser with shape, dtype, stats, a scrollable table, an image preview and CSV export. No Python.

Also known as: npy viewer · npy file viewer online · open npy file online · npz viewer · numpy array viewer · npy to csv · npy file reader online · npy image viewer · view numpy file without python

python tools

csv and spreadsheet tools

viewers

NumPy File

Drop a .npy or .npz file here, or click to browse

Read in your browser with no Python and no upload. Arrays up to 512 MB are read in full.

Array Contents

The shape, dtype, statistics, a scrollable table of values and an image of 2-D slices will appear here.

About NPY Viewer

An NPY viewer is used to look inside a NumPy .npy or .npz file without opening Python: the array's shape, dtype and values. Drop in an array saved with np.save or np.savez and this tool shows its statistics, a scrollable table, a grayscale or RGB image of any 2-D slice and the raw header, and exports the values to CSV for Excel or Google Sheets.

Key Features

Reads .npy format versions 1.0, 2.0 and 3.0 and .npz archives from np.savez and np.savez_compressed
Decodes bool, int8 to int64, uint8 to uint64, float16, float32, float64, complex, Unicode and byte strings, datetime64 and timedelta64
Shows structured record arrays as a table with one column per field
Handles C and Fortran memory order and big-endian files, with slice pickers for 3-D and higher arrays
Computes min, max, mean, standard deviation, zero, NaN and infinity counts in one pass
Draws any 2-D slice as a grayscale image and H x W x 3 arrays as RGB, and exports values to CSV

Use Cases

Check the shape and dtype of embeddings saved by a teammate before loading them into a vector database
Look at a MNIST-style image array or a segmentation mask without starting a Jupyter notebook
Open a .npz of model weights or features on a Chromebook or a locked-down work laptop with no Python
Export a 2-D NumPy array to CSV so an analyst can open it in Excel
Find NaN or infinity values that are breaking a training run
Confirm a file from a lab instrument or simulation was saved completely and is not truncated

Supported Formats

.npy v1.0, v2.0, v3.0

.npz (np.savez)

.npz (np.savez_compressed)

C and Fortran order

Little- and big-endian

Structured dtypes

Related Keywords

npy viewer

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npz viewer

numpy array viewer

npy to csv

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npy image viewer

view numpy file without python

What is an NPY file and how do you open one without Python?

An .npy file is NumPy's binary format for a single array, written by np.save. It starts with the magic bytes \x93NUMPY, a version number and a short header that is a Python dictionary literal holding the dtype (descr), the memory order (fortran_order) and the shape. The raw array bytes follow, aligned to 64 bytes. Because the header says exactly how to read those bytes, a browser can decode the file without Python. An .npz file is a ZIP archive of .npy files, one per array passed to np.savez. Arrays of Python objects are stored as pickles and need the Pickle Viewer instead.

Is my array uploaded anywhere?

No. The file is read in your browser and nothing is sent to a server, so research data, embeddings and model weights stay on your machine.

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Frequently asked questions

What is NPY Viewer used for?

NPY viewer that opens NumPy .npy and .npz files in your browser with shape, dtype, stats, a scrollable table, an image preview and CSV export. No Python.

Is NPY Viewer free to use?

Yes. NPY Viewer is completely free with no usage limits, and there is no paid tier required to use it.

Do I need an account to use NPY Viewer?

No. NPY Viewer works immediately in your browser with no signup, login, or email address required.

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