ScreenStitchV

What is ScreenStitchV?

ScreenStitchV is a free long screenshot maker that runs entirely in your browser. You take several screenshots as you scroll down a chat, a web page or an order history, add them here in order, and it finds the part that repeats between each pair, removes the duplication and joins them into one continuous tall image you can save or share.

It exists because phones are inconsistent about this. Some Android phones have a built-in scrolling screenshot and some do not; iPhones can capture a full web page in Safari but nothing else; and neither helps when the screenshots are already sitting in your gallery. ScreenStitchV works from the images themselves, whatever took them.

How to combine screenshots into one long image

1. Take overlapping screenshots. Scroll by roughly two-thirds of a screen between shots so each one shares a strip with the previous. Overlap is what the app matches on — without it there is nothing to line up.
2. Add them here, all at once. Nothing is uploaded; they are read straight from your device.
3. Check the order. Top of the page first. Drag them, use the arrows, or try Auto Arrange.
4. Tap Auto Stitch. Each seam gets a confidence rating you can see.
5. Fix anything that looks off by tapping that seam and nudging it by hand.
6. Export as PNG, JPG or WebP.

How automatic screenshot stitching works

A scrolling screenshot is an unusually easy computer-vision problem, and worth solving in the easy way. The pixels do not rotate, scale or change perspective between shots — the content simply moves straight up. So instead of general feature matching, ScreenStitchV looks for the single vertical offset at which the bottom of one screenshot equals the top of the next.

It makes a small grayscale copy of each screenshot (a few hundred pixels wide) and reduces every row to a short signature, which makes it cheap to test every possible offset. The most promising offsets are then re-checked against the real pixels, and the winner is refined row by row at full precision. Because that final refinement compares every row and every column in a narrow window, the seam lands on the exact pixel rather than a few pixels out — which is the difference between a clean join and a visibly doubled line of text.

Crucially, the analysis copies are used only to decide where the seam goes. The image you download is always drawn from your original screenshots at their original resolution.

Why a repeated toolbar does not fool it

The thing that breaks naive screenshot stitchers is a sticky header. If the same toolbar sits at the top of every screenshot, a matcher looking for "bottom of A equals top of B" will find a beautiful match at exactly the height of that toolbar and produce a confident, completely wrong seam.

ScreenStitchV models the screen the way it actually behaves — a fixed header, a moving content area, and possibly a fixed footer. It measures how many rows at the top are identical between two screenshots, treats those as the header, and searches for the content overlap below it. The same is done from the bottom for navigation bars. You can override both under Advanced if the automatic guess is wrong.

Every candidate seam is also scored across several horizontal strips rather than as one average, so a match that looks good only because both screenshots have a blank margin down each side is rejected: the strip through the middle, where the actual content is, has to agree too.

How to stitch WhatsApp chat screenshots

Chat screens are the hardest common case, because a lot of the screen is flat background and message bubbles look alike. Two things help: overlap more than you think you need — about a third of the screen — and choose the Chat preset, which expects a larger minimum overlap and is more tolerant of low-contrast backgrounds.

If a seam still comes back as Low, open it and align it by hand. The difference view makes it obvious when the two halves line up: matching pixels go dark, so you slide until the overlap region turns black.

ScreenStitchV is an independent tool and is not affiliated with or endorsed by WhatsApp or Meta.

How to stitch webpage screenshots

Web pages are the easiest case — plenty of text and structure to match on. Use the Web Page preset, which allows a smaller minimum overlap and a taller sticky header, since site headers are often large.

One thing to watch: pages with adverts or carousels that change between screenshots. The content around them still matches, so the seam is usually found correctly, but check the result near any advert.

What if ScreenStitchV cannot detect the overlap?

It says so instead of guessing. A seam that cannot be found confidently is marked Low or Failed, in words as well as colour, and you get three ways forward:

• Align Manually — a slider for the overlap plus fine X and Y nudges, an opacity control, and a difference view.
• Simple Stack — join the screenshots end to end without removing anything. Useful when there is genuinely no overlap.
• Reorder — a "no overlap found" result very often just means two screenshots are the wrong way round.

Automatic detection failing never stops you finishing the image.

Are my screenshots uploaded?

No. There is no server side to this app. Your screenshots are decoded by your browser, analysed in a Web Worker on your device, and drawn to a canvas on your device. Nothing about them — not the pixels, not the filenames, not the dimensions — is sent to Apps by V, to analytics, or to any image-processing or AI service.

They are not written to your device either: they live in the page's memory, so refreshing or closing the tab clears them completely. The only things ScreenStitchV saves locally are your theme choice and your export preferences. You can read the full privacy policy.

Can ScreenStitchV work offline?

Yes. The app is installable, and once it has loaded once the whole thing is cached on your device. Adding screenshots, ordering them, detecting overlaps, manual alignment, cropping and exporting all run locally and need no connection. There is no external computer-vision library to download at the moment you press the button, which is deliberate — a stitcher that stops working offline is not much of an offline tool.

Does ScreenStitchV reduce image quality?

Not unless you choose to. The downscaled copies are for finding the seam and are thrown away afterwards; the export is composed from your original screenshots. PNG is lossless and is the default, because screenshots are mostly text and flat colour, which is exactly what PNG handles well and what JPG smears.

JPG and WebP are offered for when file size matters, with a quality setting. You can also scale the output to 75% or 50% deliberately, or set a custom width.

Very long images

Browsers cap how large a canvas can be, and the cap is much lower on iPhone than on a desktop. Ten full-length screenshots can exceed it. Rather than handing back a blank or half-drawn image, ScreenStitchV works out the output size first and, if it is beyond what your device can safely handle, offers to reduce the resolution or to export in parts — several numbered images that continue from one another. It will not silently crop your screenshot.

Which direction does it stitch?

ScreenStitchV currently creates vertical long screenshots. That is what scrolling through a chat, a web page, a bill or an order history produces. Side-by-side panorama stitching is not part of this version.