Image Stitcher - Long Screenshots and Collages

What does this image stitcher do?

This tool combines several images into one, entirely inside your browser. Stack screenshots into a single long image for sharing, lay photos out on a square grid, or pick an asymmetric template for a collage that looks designed rather than pasted. Spacing, outer padding, background color, and corner radius are yours to tune, and a live preview shows the exact result before you export.

Key features

• Horizontal strip with equal heights, vertical strip with equal widths.
• Grid collage with up to 10 columns and square cells; trailing cells stay empty.
• Nine-grid collage preset tuned for social media feeds.
• Free grid presets: one big plus two small in four arrangements, one big plus a 2×2 grid, plus plain 2×2 and 3×3 layouts.
• Template canvas ratios: 1:1, 4:5, 3:4, 2:3, 9:16, 16:9.
• Cell fill per image: crop to fill, or fit whole with letterbox.
• Adjustable gap (0-100px), outer padding (0-200px), corner radius (0-30% of the cell's shorter edge).
• Background color picker plus transparent background for PNG and WebP output.
• Free grid layout up to 10×10: drag a cell to move it with grid snapping, drag any edge or corner to resize it, and drop a cell on a same-sized one to swap the two.
• Per-cell image choice: click a cell to pick from the pool or upload straight into it; click empty grid space to add another cell, and press × to delete one.
• Seven starting presets; every grid value stays editable after applying one.
• Cells never overlap or leave the grid bounds, and empty cells keep their slot.
• Uniform grid mode keeps click-two-cells-to-swap for reordering.
• Reorder via the thumbnail strip; images are placed in queue order.
• Live preview rendered by the exact export code path.

How to use it

1. Drop images onto the upload area or click to browse. Up to 100 at a time.
2. Pick a scenario preset, or choose a layout mode directly. Free grid mode starts from an empty canvas, so fill it cell by cell.
3. Adjust gap, padding, corners, and background while watching the preview.
4. Reorder images by dragging their thumbnails, or in free grid mode rearrange the cells themselves.
5. Check the output size shown under the preview, then download.

Which layout fits which scene?

Long screenshot chains and chat logs belong in the vertical strip: it keeps every image at its natural width and stacks them with no gaps by default. Product comparisons work best as a horizontal strip, where equal heights make differences easy to see side by side. Square grid collages with rounded corners and white padding suit social media posts, and the nine-grid preset is a one-click version of the same idea. When two or three photos should dominate the composition, switch to free grid mode, size the hero cell to carry the main subject, and click each remaining cell to choose what goes in it.

How big can the output be?

The tool shows the exact pixel size of the stitched canvas before you export. Vertical strips of many tall screenshots can grow very large; above 16384px on the long edge you get a warning because older devices may fail to render, and beyond 30000px export is blocked since browsers cap canvas dimensions around 32767px. Split very long captures into sections and stitch those instead.

Privacy and security

All decoding, compositing, and encoding happen locally inside your browser tab through the Canvas API. No image ever leaves your device, nothing is stored after you close the page, and object URLs are released when you remove files or leave. Stitched material often includes private conversations, so local processing is not just a performance choice.

FAQ

Can I control the order of the images?

Yes. Images are placed in queue order. Drag any row onto another to swap positions, or nudge images with the up and down arrows next to each row.

What happens when I add more images than the layout needs?

Grids fill row by row and leave trailing cells empty, showing the background color. In the free grid, new images fill empty cells first, then create cells on any free grid space; anything that still does not fit stays in the pool, is reported under the preview, and is simply left out of the export — the download always stays available.

Fill or fit?

Fill crops each image from its center until it covers the cell, which keeps layouts tight but trims edges. Fit shrinks the image until it is fully visible inside the cell, leaving letterbox areas in the background color. Screenshots usually look better fitted; photos usually look better filled.

Why did my narrow image get wider?

Strip modes normalize sizes: horizontal strips give every image the tallest height in the batch, and vertical strips give every image the widest width. A narrower screenshot is scaled up to match so the seam is seamless. If upscaling bothers you, pre-crop the images to similar proportions first.