Every December, a few hundred thousand developers work through Advent of Code and a good number of them post their solutions. Almost always as images, and almost always badly sized.

The reason images win is straightforward. Most platforms mangle pasted code — indentation collapses, syntax colouring vanishes, and a clever one-liner becomes an unreadable smear. An image survives all of that. The tradeoff is real and worth stating: an image cannot be copied, searched, or read by a screen reader, so post a link to the source alongside it.

Post the interesting part, not the whole file

The most common mistake is screenshotting the entire solution file. Nobody reads a 60-line image on a phone. Advent of Code solutions almost always have one interesting idea in them — the parse, the recurrence, the trick that turned the brute force into something instant. Screenshot that, and let the repository link carry the rest.

Ten to fifteen lines is the ceiling for something readable in a timeline.

Size it for the platform, not for your screen

This is where most solution images fall down. A snippet that looks fine on a 27-inch monitor becomes six-point text in a feed.

  • A timeline post wants 16:9 or 4:3. Wider than that and the text shrinks to fit.
  • A vertical feed wants 9:16 or 3:4, which suits the tall, narrow shape most solutions have anyway.
  • Anywhere at all wants a 2× or 3× export, because a 1× image on a retina display looks soft and slightly amateur.

In Codeshot that is the Aspect Ratio section — switch from Original to Fixed, pick the ratio, and set the export scale. Same three controls every time.

Pick a theme with contrast

December threads are a wall of code images, and the ones that get read are the ones you can read at a glance. High-contrast themes carry small text better than subtle ones. Tokyo Night, Atom One, and Solarized all hold up when scaled down; several of the lower-contrast themes do not.

You can compare all 30 side by side here before you commit to one for the month.

Be consistent for the whole 25 days

If you are posting daily, decide the theme, backdrop, and ratio on day one and never touch them again. Consistency is what makes a series recognisable in a feed — and practically, it removes the twenty seconds of fiddling that is the actual reason people give up posting around day eleven.

A native app helps here because it remembers your setup between launches. Set it up on the first, and every subsequent day is paste, export, post.

A note on spoilers

Advent of Code's creator asks people not to post solutions publicly before the leaderboard fills. Check the current year's guidance, and if in doubt, post after the day is done rather than during.

If you want the full workflow, it is in How to Turn Code Into an Image.