About PetPrintKit
Last updated 2026-09-09
PetPrintKit answers one question a pet portrait seller asks on every order: will this photo actually print? It takes the snapshot a customer emailed you, tells you the largest size it can carry, removes the background without shredding the fur, crops it correctly for each print size, and hands back a ZIP. The whole thing runs in your browser.
Where this came from
I am a web developer, and I build tools for specific niches. They all start the same way: I run into a problem myself, work around it by hand a few times, and eventually get tired enough of the workaround to build the thing that removes it. Not a platform, not a suite. One job, done properly.
Pet portrait printing had a good one. The question that keeps coming back is whether a customer’s photo will hold up at the size it is being sold at — and the arithmetic that settles it is not difficult, just fiddly, easy to get subtly wrong, and tedious to redo for every order. Getting it wrong is expensive in a specific way: you find out after the print comes back soft. That is the shape of problem worth building for rather than repeating.
It is also why this site is built the way it is. Nothing here asks you to trust my eye or my taste. The claims are arithmetic, the arithmetic is published, and the pages showing it are generated from the same code that produces your files — so you can check the working.
Who it is for
Sellers, not pet owners. The people this is built for run Etsy shops and print-on-demand storefronts, or illustrate from a reference photo a customer sent them — and they all share the same problem, which is that the input is a phone snapshot rather than a finished artwork file.
That distinction drives everything here. Most print-prep tools assume you already own a clean, high-resolution file and just need it resized. This one starts a step earlier, at the point where you are looking at a WhatsApp photo of a spaniel and trying to work out whether you can honestly sell it as a 16x20.
Why the numbers here are not the same as everyone else’s
Our print size figures are computed after the aspect-ratio crop. Nearly every other chart divides pixels by inches and stops there, which quietly overstates what a photo can do.
Here is the difference in practice. A 12 MP phone photo is 3024x4032 pixels in a 3:4 shape. Printed at 8x10 inches — a 4:5 shape — some of those pixels are cropped away before anything reaches paper, so the resolution that matters is the resolution of what survives the crop, not of the original file. A chart that skips that step will tell you a photo clears 300 DPI when it does not.
Every number published on this site — the 11 print sizes, the 10 megapixel reference pages, the tables in the guides — is generated at build time from the same modules the tool itself computes with. Nothing is typed into a page by hand. If the tool gives you a verdict, the chart on the site agrees with it, because they are the same arithmetic.
Two thresholds appear throughout: 300 DPI, the standard for a print someone will look at closely, and 200 DPI, which is honest for a framed piece viewed from across a room. We say which one a photo meets rather than reducing it to pass or fail.
Why nothing is uploaded
There is no upload endpoint, because there is no server to upload to. Decoding, background removal, cropping, mockup compositing and ZIP packaging all happen inside your browser through WebAssembly. The background-removal model is fetched once and cached locally, so returning visits download nothing.
This is not a policy promise, and you do not have to take our word for it. Open your browser’s network tab, run a photo through the tool, and watch for a request carrying the image. There is not one. That matters because the photos are not yours — they belong to a customer who sent them to you for a specific job, and shipping them to a third-party server is a decision most sellers never got asked about.
The privacy page sets out exactly what does and does not leave your machine, including the two requests that do reach a server and why neither carries a photo.
Exports are honest about resolution
Files come out as PNG at the resolution the photo genuinely has. Nothing is upscaled to hit a target number, because upscaling adds no detail — it only puts a larger figure in the file properties while the picture stays exactly as soft as it was. The correct DPI value is written into the PNG metadata so print software reads it properly instead of assuming 72.
What it costs
The tool is free and unlimited. Every print size, the background removal and the listing mockups all work without an account, without a file cap and without a trial clock; exports carry a watermark. Clearing it costs $5 once for a single photo, or $19 a month for everything. The pricing page spells out the boundary.
Who makes it
PetPrintKit is built and operated by SJMSaaS, an independent software company. It is a small operation rather than a large one, and it is not affiliated with Etsy, Printful, Printify, Gelato or any other marketplace or print provider. Those names appear on this site only because sellers need their file specifications met.
Corrections
If a number on this site is wrong, we want to know, and we will fix it and say that we did. The 6 guides and the reference charts are maintained rather than published and abandoned — print specifications drift, and a stale chart is a liability for whoever trusts it.
Tell us what you found. Point at the page and the figure you think is off, and if you are right the correction ships.