napari vs VTK
A data-driven comparison of two Python 3D & scientific visualization libraries: popularity, development activity, licensing and installation. Updated .
Key differences
- VTK has 1.2× as many GitHub stars as napari (3.2K vs 2.8K).
- VTK had more development activity over the last 12 months: 5,786 commits vs 745.
- VTK is downloaded 38× as often on PyPI (1.3M vs 34.7K per week).
- napari is licensed under BSD-3-Clause; VTK under BSD.
- napari is written primarily in Python, VTK in C++.
- VTK is the older project: its repository was created in 2010, napari's in 2018.
By the numbers
- napari
- VTK
Show data as a table
| Metric | napari | VTK |
|---|---|---|
| GitHub stars | 2,791 | 3,224 |
| PyPI downloads / week | 34,687 | 1,332,307 |
| Commits, last 12 months | 745 | 5,786 |
| Contributors | 228 | 257 |
| Forks | 569 | 1,309 |
Development activity
Commits per month to each default branch, last 12 complete months.
- napari
- VTK
Show data as a table
| Month | napari | VTK |
|---|---|---|
| Nov 2025 | 11 | 366 |
| Dec 2025 | 45 | 345 |
| Jan 2026 | 53 | 570 |
| Feb 2026 | 54 | 496 |
| Mar 2026 | 55 | 445 |
| Apr 2026 | 60 | 373 |
| May 2026 | 43 | 378 |
| Jun 2026 | 52 | 515 |
| Jul 2026 | 114 | 566 |
| Aug 2026 | 76 | 534 |
| Sep 2026 | 50 | 636 |
| Oct 2026 | 132 | 562 |
Side by side
| Attribute | napari | VTK |
|---|---|---|
| Description | Fast, interactive viewer for multi-dimensional images in Python. | Open-source library for 3d Graphics, image processing and visualization. |
| Category | Python 3D & scientific visualization libraries | C++ visualization libraries & applications |
| License | BSD-3-Clause | BSD |
| Language | Python | C++ |
| Status | Active | Active |
| Latest release | v0.10.0 () | – |
| Last commit | ||
| Repository created | ||
| Open issues | 1,091 | 0 |
| Install | pip install napari | pip install vtk |
Which should you choose?
Popularity and activity are only part of the story. Consider which ecosystem you work in, the chart types and interactions you need, how much data you render, and whether the license fits your project. Both tool pages list alternatives if neither is quite right.