**Butterfly Viewer** can view multiple images side by side with synchronized panning and zooming. Simply drag and drop image files into it and it'll auto-arrange them as a grid, column, or row. I'm the creator, and I recently released it to the public on [GitHub][1]. You can [install it on Windows][2], run it as a [package for MacOS (beta)][3], or run it directly on its Python source code. GIF of drag-and-drop with synchronized zoom and pan ![GIF of drag-and-drop with synchronized zoom and pan][4]. Image of six photos individually panned and zoomed ![Image of six photos individually panned and zoomed][5]. [1]: https://github.com/olive-groves/butterfly_viewer [2]: https://olive-groves.github.io/butterfly_viewer/butterfly_viewer.html#windows-executable [3]: https://olive-groves.github.io/butterfly_viewer/butterfly_viewer.html#macos-app [4]: https://olive-groves.github.io/butterfly_viewer/images/viewer_dragdrop_sync.gif [5]: https://olive-groves.github.io/butterfly_viewer/images/viewer_eindhoven.jpg