What this tool does
Stitching joins several images into a single picture in the order you choose. Vertical mode stacks each image below the previous one, which suits chat logs, long documents and full-page screenshots. Horizontal mode places them side by side, which suits comparison shots that belong on one canvas. Everything happens inside your browser and no image is uploaded to any server.
The problem this solves is simple: a set of images needs to travel as one file instead of forcing the reader to open them one by one. Chat transcripts, walkthroughs, specification comparisons and multi-screen design previews all hit the same wall. Merging scattered screenshots into one long image makes them easier to read and stops them from being re-compressed or dropped while forwarding.
How to use
- Pick your images Drag the images onto the drop area above, or click it and select several files at once. Up to 20 images, each no larger than 50MB. The order you select them is the order they are placed: top to bottom when vertical, left to right when horizontal.
- Choose direction and gap Under the options pick Vertical (stack) or Horizontal (side by side). The gap defaults to 0, meaning a seamless join; 10 to 40 pixels gives each image breathing room, and the gap is filled with the background colour.
- Set background and format The background colour fills the canvas margins and the gaps, and it is what shows through wherever the images do not cover the canvas. Output defaults to JPG because it is smaller; choose PNG when you need transparency preserved. The quality slider only affects JPG, and 90 is already hard to distinguish from the original.
- Stitch and download Hit the stitch button and download the result once it appears. If the finished image is longer than the longest-side limit, the whole layout is scaled down proportionally to fit and the result explains that. Setting the limit to 0 disables it, although a total-pixel guard still protects memory.
FAQ
Why did one image shrink after stitching?
All images are aligned to the smallest width (vertical) or height (horizontal) so nothing is distorted. If one image is much wider, it is scaled down to the shared size and its height drops accordingly. Grouping images of similar dimensions keeps the loss minimal.
How many images, and how large?
Up to 20 images at a time, each no larger than 50MB. The real constraint is memory: stitching holds every decoded bitmap at once, so more images means more memory. If it feels sluggish, stitch in batches and then stitch the batches together.
Are my images uploaded?
No. Decoding, layout and encoding all run inside your browser, so files never leave your device and no upload bandwidth is used. The page even keeps working offline once you have visited it.
How do I keep transparency?
Set the output format to PNG and the background to Transparent. JPEG has no alpha channel, so choosing JPG together with Transparent falls back to white; the option help says the same thing.
Is the stitched result blurry?
As long as the longest-side and pixel limits are respected, the tool only downscales or leaves images as they are; it never upscales, so it cannot invent blur. The real loss comes from re-encoding: JPG starts showing artefacts below quality 60, so keep it at 80 or above. For screenshots, PNG is the safer choice.
Can it stitch GIF or SVG?
No. An animated GIF would contribute only a single frame, and SVG is a vector format that cannot be used directly as a bitmap input. Convert them to PNG or JPG first, then stitch.
Limits
This is stitching, not collage: it lays images out along a single line and offers no templates, grids, rounded corners or borders. For a nine-grid layout or multi-column composition, use a dedicated collage tool.
The longest side defaults to 4096 pixels and the whole result is scaled down if it goes over; the total-pixel ceiling is fixed at 40 million to keep an oversized canvas from exhausting memory, and the cross-axis baseline is capped at 2400 pixels. All of these are visible in the options, and the result tells you whether any reduction happened.
Re-encoding drops EXIF, so capture time, camera model and GPS are not carried into the result, which is good for privacy. Format and quality decide the final size and look, so prefer PNG when the output is meant to be archived or printed.