Merge screenshots into one long image

Drop in the screenshots you already took, in order. The overlapping strips are found automatically and the seams are joined into a single tall image you can download. It is free, there is no sign-up, nothing is watermarked — and your screenshots never leave this browser.

This is a simplified demo. It is not how well the Scrollie app does it. The browser version uses a cut-down alignment algorithm, so seams can land slightly off when screenshots repeat their content, contain large flat areas, or barely overlap. Scrollie on iPhone runs the full algorithm, and also turns a screen recording straight into one long image, drops duplicate frames and saves drafts — that is what this job actually looks like done properly. This page is just a taste of the idea.

How to use it

1. Capture with overlap. Scroll a little less than a full screen between shots, so each screenshot repeats roughly a fifth of the previous one. That repeated band is what the alignment is built on.
2. Add them in order. Drop all the images in at once, or one at a time. Use the arrows under each thumbnail if the order came out wrong.
3. Stitch and download. Choose PNG for a lossless result or JPG for a smaller file, then download. Nothing is stored here after you close the tab.

Why the seams line up

Joining screenshots by hand means dragging one image over another until the text lines up, then cropping the duplicate. It works, and it is tedious. What this tool automates is finding that alignment point.

It takes a narrow strip from the top of each screenshot and searches the previous screenshot for the place that strip fits best. That position is the seam. To keep it fast the search runs on a small greyscale copy of each image rather than the full-resolution original — a phone screenshot can be nearly four megapixels, and comparing those directly for every candidate position would lock up the page.

There is one complication worth knowing about, because it explains a failure you may have seen in other tools. The status bar at the top of a phone screenshot is nearly identical in every frame, and so is a fixed navigation bar or tab bar. A matcher pointed at those regions finds an excellent match in the wrong place, and the result is a long image with the clock repeated down its length. This tool compares your images to each other first, identifies the rows that never change, and leaves them out of both the matching and the final composition. That is the Ignore status & navigation bars option, and it is on by default.

When a match is weak — usually because two screenshots do not actually overlap — you are told rather than left to discover it in the output. The images are still joined end to end so you get something usable, but the warning tells you which pair to re-capture.

When the app is the better tool

This page does one job: joining still screenshots you already have. That covers a lot of cases, and if it is what you need there is no reason to install anything.

Some things genuinely belong on the device. Turning a screen recording into one long image means pulling frames out of a video, discarding near-duplicates and stitching what remains — that is the Scrollie app's core feature, and it works on the recording already sitting in your camera roll. The same goes for capturing in the first place: a browser cannot scroll another app for you.

The practical ones matter too. A browser tab cannot keep a draft, so if you close this page mid-edit the work is gone; the app auto-saves everything and keeps portrait and landscape drafts separately. Long batches, per-cell editing, erasing an object from the result, removing a tiled watermark — all of that is app territory. This tool is capped at eight images on purpose, because past that the browser is the wrong place to be working.

Common questions

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