Instant stepping
The images either side are decoded before you press the arrow, the window never flashes empty, and going back further shows a preview at once.
- Neighbours first, never before. Once the current image is on screen, the next and the previous decode on background threads, so stepping onto them takes a few milliseconds for every format.
- No flash. The window keeps the current image up until the next one is decoded and its orientation is known, so a photo never shows sideways for a frame, nor an empty canvas.
- Back is quick too. The last two dozen images leave a small preview behind, shown at once at the full image’s size while the full resolution decodes again.
- Many keys for it. →, Space and Page Down step forward; ←, Backspace, Shift+Space and Page Up back; Home and End jump to the ends.
See The folder.