How much text actually fits on an App Store screenshot

Your caption is designed at 1290 pixels wide and read at a fraction of that. The arithmetic decides the type size, and it is not a matter of taste.

Published: 31 August 2026

The mistake is designing at 100%

A screenshot is exported at, say, 1290 × 2796 and reviewed on a desktop at something close to full size, where a 48-pixel caption looks enormous. It is then displayed in a list of results, three across, at a small fraction of that width — and the caption that looked enormous is a grey smudge.

Nobody needs a rule of thumb here, because the arithmetic is available to anyone with a phone.

Do the measurement yourself

1. Open the App Store on the device you care about and find any listing with screenshots.
2. Screenshot the store itself, then measure how wide one of those thumbnails is in your capture, in pixels.
3. Divide your export width by that number. That is your downscale factor.

If a 1290-pixel-wide export is displayed 150 pixels wide, the factor is roughly 8.6, and a 48-pixel caption is being read at about 5.6 pixels tall. That is not a small caption; that is an absent one.

Do this once, write the factor down, and design against it forever. It is the difference between a caption that works and a caption that only worked on your monitor.

What survives

Rather than a type size in pixels, which stops being true the moment the export size changes, think in percentages of the image width:

Element	Share of image width	On a 1290 px export
Caption headline	6–9%	≈ 80–115 px
Supporting line	4–5%	≈ 50–65 px
Below 4%	—	treat as decoration

Those percentages are a starting point you then verify with the measurement above, not a specification. The point of expressing them as a share is that they stay true when Apple adds another display class.

Words, not sentences

At that size the limit is not characters, it is words. Three to five, one line, no punctuation you have to resolve. “Every token, your amounts” reads at thumbnail size. “Configure your portfolio with unlimited tokens and custom amounts” does not read at any size, because by the time it could be read the reader has scrolled.

The second and third screenshots can carry more, because anyone who has swiped to them has decided to look. The first one is doing a different job and needs to be written differently.

The band, and what it costs

Putting the caption in a solid band above the screen is the most common layout, and it works, but it is not free: every pixel of band is a pixel not showing the app. A band that takes a third of the height turns a screenshot into a poster with a small illustration on it.

The alternative — caption overlaid on a blurred or darkened area of the screen itself — keeps the app at full size but only works when there is a genuinely quiet region to put it on. Look at your screen before choosing; if the top third is a dense list, the band is the honest answer.

One set, one system

Same type size, same position, same band height on all of them. A set where the caption moves from image to image reads as unfinished even when each image is individually fine — and unlike type size, that one is visible at thumbnail scale, because position is the first thing the eye tracks.