Scroll Screenshot Joiner

Combine screenshots into one image online — duplicate overlapping rows between frames are auto-detected and removed, then stitched into a single long PNG. Runs entirely in your browser. No upload. No servers.

🖼️

Drop scroll screenshots here

or click to browse · PNG / JPG / WebP · Multiple files

Output format

JPEG quality 92%

Overlap detection sensitivity

Lower = stricter match (fewer false removals). Higher = more tolerant (finds overlap even through subtle compression artifacts).

How it works

When you scroll and take screenshots, each new frame overlaps the previous one by a strip of pixels. This tool detects and removes those duplicate strips before stitching.

1Load images Drag your scroll screenshots in order (top to bottom). The tool reads them locally — nothing leaves your device.

2Detect overlap For each pair of consecutive images, the bottom rows of the first frame are compared pixel-by-pixel with the top rows of the second to find where they match.

3Remove duplicate rows The matching overlap strip is trimmed from the top of each subsequent image so content is never duplicated in the final output.

4Stitch & download All trimmed frames are composited onto a single canvas and exported as PNG or JPEG. One click to download.

The overlap search scans strips of varying height (from 10 px up to 40% of the shorter image) and picks the largest clean match. Sensitivity controls how strictly pixels must match — useful when screenshots have compression artifacts.

Frequently asked questions

Do my screenshots get uploaded to a server?: No. This tool runs entirely inside your web browser using the Canvas API and FileReader API. Your images never leave your device — there is no server involved at any step. This is particularly important for screenshots of private conversations, documents, or banking pages.
In what order should I add the screenshots?: Add them top-to-bottom, meaning the first screenshot should show the beginning of the content and the last should show the end. If the order gets mixed up you can drag files into the list in the correct order — the tool stitches them in the order shown in the file list.
What is "overlap detection sensitivity" and when should I change it?: Sensitivity controls the maximum average pixel difference allowed between two candidate rows for them to be considered a match. A value of 8 (the default) works well for lossless PNG screenshots. If your screenshots were saved as JPEG or came from a video frame grab, they may have compression noise — increase sensitivity to 12–18. Decrease it if the tool is incorrectly trimming non-overlapping rows.
What if my screenshots have different widths?: The tool uses the widest image as the canvas width and centres narrower images. Overlap detection is performed on the minimum shared width, so slight width differences (e.g. one screenshot taken with the browser scrollbar visible) do not prevent stitching.
How many screenshots can I stitch at once?: There is no hard limit imposed by this tool. In practice, very long pages (30+ screenshots at full resolution) can produce a canvas exceeding browser memory limits. If that happens, try exporting as JPEG at lower quality, or split the job into two halves and stitch the halves together afterwards.