Most CMS platforms default to showing the 10 or 15 most recent posts in an RSS feed, and for the vast majority of sites, that default is already close to right. The number matters more than it looks, though, because it directly controls how much of your history any given automation tool or reader can actually see.
An automation tool detects “new” content by comparing what’s currently in your feed against what it’s already seen. If your feed only holds 10 items and you publish 15 posts in a short burst (a migration, a bulk import, a catch-up after time away), the oldest 5 of those never appear in the feed at all — and a tool that only checks the feed, rather than your full archive, will simply never see or post them.
A feed capped too low mainly bites during unusual publishing bursts, not normal day-to-day posting. If you publish once a day and your feed holds 15 items, you have roughly two weeks of buffer even if a check gets delayed — plenty of margin. If you batch-publish multiple posts at once, a low item count can silently skip the overflow with no error or warning.
Going too high isn’t dangerous, but it isn’t free either — a feed with hundreds of items takes longer to generate and fetch, uses more bandwidth on every check, and gives automation tools more data to parse for no real benefit, since they only care about what’s new since last time. There’s a genuine point of diminishing returns past roughly 20–30 items for most use cases.
15–20 items is a sensible default for most blogs and news sites, comfortably covering normal publishing cadence with margin for an occasional multi-post day. If you publish in bursts — several posts at once on a regular schedule, or after planned gaps — raising it to 30–50 gives real headroom without meaningfully impacting performance. Most CMS platforms let you adjust this in reading or feed settings without any plugin required.
Open your feed URL directly and count the <item> entries, or check your CMS’s reading/feed settings, where this is usually a simple numeric field.
Not meaningfully for typical blog-sized increases (going from 10 to 30, for example) — the difference becomes noticeable only at very large counts (hundreds of items) or on already-slow servers.
Raising the count is the simplest fix; the alternative is spacing out publishing so fewer posts land in any single automation check window, but that’s usually more disruptive to your workflow than just adjusting one setting.
Your feed’s item count is a buffer against timing gaps between publishing and automation checking it — too low risks silently skipping content during publishing bursts, too high adds unnecessary overhead with no real benefit. 15–20 items covers most sites; bump it higher only if you know you publish in batches.
