Stack images, vertical or horizontal, one canvas

Combine multiple images into one canvas, vertical (top to bottom) or horizontal (left to right). Adjustable gap, alignment, and background colour. Great for screenshot threads, comic panels, before/after.

Questions

Is Stack Images free?
Yes. Stack Images is completely free, with no account, no sign-up, and no usage limits. It runs entirely in your browser.
Do my files get uploaded?
No. Stack Images processes everything on your device, so your files never leave your browser. You can verify it yourself: open your browser's DevTools, watch the Network tab, and you'll see nothing gets sent.
How do I use Stack Images?
Combine multiple images into one canvas, vertical (top to bottom) or horizontal (left to right). Just drop your image in above, everything happens locally in your browser, so it's instant and private.
Is there a file size limit?
There's no hard limit. Because Stack Images works locally, the only ceiling is your device's memory, larger files simply use more RAM. Nothing is capped by a server.

More free, browser-only image tools, nothing uploaded, ever.