Show IH: I built PhotoCollageMaker io – a free browser-based photo collage tool (pure front-end, no backend required)

Hey IH folks 👋

I’d like to share a project I recently built: PhotoCollageMaker.io.
It’s a completely free, privacy-friendly tool for making photo collages right in the browser. No accounts, no backend, and no hidden paywalls.

Why I built it

I kept running into the same issues whenever I wanted to make a quick collage:

Tools were bloated (heavy apps or signup walls)
Export was often locked behind a subscription
Uploading personal photos to random servers didn’t feel safe

So I decided to make something that’s:

100% front-end only (runs locally in the browser)
Zero dependencies on a backend (nothing gets uploaded, all client-side)
Simple by design → one job: make collages quickly

Technical side 🛠️

The stack is intentionally lightweight:

Vanilla JavaScript + Canvas API for rendering images into a collage.
HTML5 FileReader → loads images directly into memory.
Canvas 2D Context → handles resizing, positioning, and drawing images into a grid or custom layout.
Canvas toDataURL / toBlob → for instant download in PNG/JPEG format.
CSS Grid & Flexbox → power the drag-and-drop layout previews.
No external libraries for core features (keeping it fast and dependency-free).

Because everything runs client-side:

Images never leave the browser.
Performance is good enough for most casual use cases (I tested up to ~20 photos per collage on mid-range laptops and phones).
Export is nearly instant, since it’s just canvas → blob download.

Challenges I ran into

Image scaling & quality – making sure large images don’t crash the browser while keeping exports crisp. I ended up implementing a simple downscaling strategy on load.
Mobile performance – phones handle canvas differently; optimizing memory usage was key.
Layout flexibility – I started with fixed grids but later added dynamic grid generation so collages could adapt to any number of photos.

What’s next

I’m experimenting with:

GPU acceleration via WebGL/WebGPU for faster rendering of many images.
Adding Web Workers to offload heavy operations (like scaling).
Exporting in WebP for smaller file sizes.
More layout templates (shapes, story formats, creative grids).

Try it out

👉 https://photocollagemaker.io

Everything should work instantly — just upload some images and download your collage. Would love to hear from you all:

If you’ve built front-end only tools, how did you handle performance bottlenecks?
What would you want in a “minimal but powerful” collage tool?

Thanks for reading, and looking forward to your thoughts 🙏