Compare Two Images Side by Side: Build Your Own App
If you’ve searched for a “compare two images side by side app,” you’ve probably noticed most options are either bloated photo editors or clunky online tools that don’t fit your actual use case. Here’s a faster path: build the exact image compare app you need, in minutes, with Auto.
Why build your own instead of downloading one
Most image compare apps are built for a generic audience — general photo editing, real estate before/afters, or fitness progress pics. If you’re trying to align two images to compare differences for something specific, like checking a sketch against a photo reference for proportion accuracy, you end up fighting a tool that wasn’t made for that.
Auto flips the process. You describe what you want, snap or upload a photo, and Auto builds a personal mini-app — a “Frame” — around your exact need. No app store listing, no settling for someone else’s idea of what a photo overlay tool should do.
Building a sketch-to-photo comparison tool in Auto
Say you’re an artist who wants to check your sketches against reference photos for proportion errors. Here’s the shape of it:
- Open Auto and describe the tool you want: a way to compare a sketch against its photo reference to check proportions.
- Ask for a storage area so every image you upload — sketches and references — stays organized in one place.
- Ask to select a reference image and a sketch image, then overlay them in a single canvas view.
- Ask for the ability to pick which image is “active,” then move and scale it using two-finger scroll and pinch gestures, so you can slide the sketch over the reference and see exactly where proportions drift.
Auto writes the actual app for you. You’re not coding — you’re just describing what the tool should do, the same way you’d explain it to a person.
How someone built theirs
One Auto user wanted exactly this: an overlay images online free tool for checking sketch proportions against photo references. They started simply, asking Auto to build a Frame that stored all their uploaded images, let them pick a reference and a sketch, and overlaid the two in a canvas view with pinch-to-scale and two-finger-move controls on the active image.
When the build came back with a few TypeScript errors — touch event types and a component prop mismatch, the kind of thing that happens with any custom software — they simply pasted the error log back into Auto and asked it to fix them. Auto resolved the issues and rebuilt the app. No debugging skills needed on their end; they just reported what broke.
The result, now shared as a working example called “Sketch Compare,” shows what’s possible: a real image compare app built around one person’s actual workflow, not a generic template.
FAQ
Can I build a photo overlay tool to spot differences without knowing how to code? Yes. You describe what you want in plain language, upload a sample image if it helps, and Auto builds the working app. If something breaks, you paste the error back in and Auto fixes it.
How is this different from a free online image comparer? Generic overlay tools handle basic side-by-side viewing. A Frame you build is tailored to your workflow — your image types, your gestures, your storage — and keeps improving as you ask for changes.
What if I need something more advanced later, like measurement grids or opacity sliders? Just ask Auto to add it. Since it’s your own Frame, you can keep refining it instead of searching for a different app.
Is Sketch Compare something I install? No — it’s proof of what one person built for themselves. Your version would be built around your own images and habits, starting from scratch in Auto.