Contrast Card Generator

Use it offline: install the generator like an app

The whole generator runs in your browser — so once you've opened it once, you can install it like an app and keep making and printing cards with no internet at all (handy on a hospital ward, on a trip, or anywhere the wifi is flaky).

Design opinionUpdated Jul 23, 2026For parents, caregivers

Our reasoned design choice, clearly labelled as such.

In one line

The whole generator runs in your browser — so once you’ve opened it once, you can install it like an app and keep making and printing cards with no internet at all (handy on a hospital ward, on a trip, or anywhere the wifi is flaky).

Key points

  • The tool does all its work on your device — sizing, drawing, and building the print-ready PDF. There is no server doing the work, so there is nothing that needs a connection once the page has loaded.
  • Your browser can install it to your home screen or desktop (look for “Install app” or “Add to Home Screen” in the browser menu). It then opens in its own window like any app.
  • After the first visit it works offline: open it on the plane, in a waiting room, or in a NICU with patchy signal, and you can still generate a set of cards and save the PDF.
  • Because it’s all on-device, this is also the privacy story: no accounts, and any photo you convert never leaves your phone or laptop — the same reason the app can work with the network switched off.

The evidence

  • [our design opinion] We deliberately built the app to do 100% of the work in the browser (no server compute), for privacy and cost reasons — see technology stack and goals. A pleasant side effect of that choice is that it can be made to run offline: if the browser has already cached the app, there is nothing left to download to make a card.
  • [practitioner guidance] Offline changes nothing about print scale. Whether you’re online or off, the PDF is built to exact physical size — you still must print at 100% / Actual size, never “Fit to Page.” See Print at 100%: why "Fit to Page" quietly ruins a correctly-sized card.

Practical takeaways

  • Open it once while you have signal, then install it (browser menu → “Install” / “Add to Home Screen”). After that it’s available offline.
  • Planning ahead for a trip or a hospital stay? Generate and save the PDFs you want in advance — but you don’t strictly have to; you can also make new ones offline.
  • Uploading a family photo to turn into a card? It’s converted on your device, online or off — it is never uploaded (see Faces first — and why your own photos make great contrast cards).

Caveats & disclaimer

  • This is a convenience and privacy feature, not a medical one. The cards remain a non-medical enrichment / accessibility tool — for premature, CVI, low-vision, or any health question, defer to your clinicians. See Mounting patterns safely near a baby (and safe sleep) for safe use near a baby.
  • “Offline” depends on your browser having cached the app from an earlier visit; a brand-new device with no prior visit will need to load it once first.