A logo spends most of its life small. Favicon, app icon, social avatar, the corner of an invoice, an embroidered shirt pocket. If it only works at 500 pixels wide on a white slide, it is an illustration, not a logo.

What breaks first

Thin strokes. A hairline that looks elegant at 400px disappears at 32px, or worse, turns into a broken grey smear. Anything under roughly 8% of the mark height is a risk.

Tight counters. The enclosed spaces inside letters like a, e, g and inside your symbol fill in when scaled down or printed on absorbent stock. Open them up more than looks necessary at large size.

Gradients. At small sizes a gradient reads as one muddy mid-tone. It also fails in one-colour printing, embroidery and engraving.

Detail count. Every extra element competes for the same handful of pixels. If your mark has a building, a tree, a swoosh and a sun, only one of them survives.

Long taglines locked to the mark. Legible on a billboard, invisible everywhere else. Make the tagline detachable.

The three-test rule

Before I call a logo finished it has to pass all three:

16 pixels. Export it at favicon size and look at it on a real screen, not zoomed in. Is it still recognisable as itself?

Pure black on white, and pure white on black. No colour, no gradient, no shadow. If the shape does not carry the identity on its own, colour is doing work it cannot always do.

Blur test. Apply a heavy blur. A strong mark keeps a distinctive silhouette. A weak one turns into a grey blob you could confuse with a hundred others.

Designing for the small end first

Try building the mark at 32 pixels and scaling up, rather than the reverse. It forces simplicity early instead of asking you to amputate details you already fell in love with.

Deliver a small-size variant

Serious identities ship more than one lockup: a full version, a compact version, and an icon-only mark for avatars and app icons. Thickening strokes slightly and dropping the finest details in the small variant is normal practice, not cheating.

The test of a logo is not how it looks in your presentation. It is whether someone recognises it in a browser tab from across the room.