All four egg-farming methods are covered by their own page on this site, but if you just want the differences side by side, here they are.
| 0 · Organic | 1 · Free-range | 2 · Barn | 3 · Cage | |
|---|---|---|---|---|
| Outdoor access | Required, with mandatory pasture rotation | Required | None | None |
| Indoor space | Max 6 hens per m² | Max 9 hens per m² | Max 9 hens per m² | Min 750cm² per hen (enriched cages) |
| Feed | Certified organic only | Standard feed | Standard feed | Standard feed |
| Flock cap | Max 3,000 birds | — | — | — |
Figures are UK/EU regulatory minimums and maximums, not averages -- individual farms can and do exceed them. Sources: RSPCA standards comparison for laying hens; egginfo.co.uk.
The short version
Organic and free-range hens both get outdoor access -- organic goes further, requiring certified organic feed and a lower indoor stocking density too. Barn hens get the same indoor space allowance as free-range, but no outdoor range at all. Cage systems today mean enriched cages, not the old battery cages -- more space and features like perches than the cages they replaced, but still no outdoor access and the least space of the four.
Want the full picture on one type? See Organic, Free-range, Barn, or Cage eggs. Or head back to what the code on your egg means.