One Draft, Five Platforms: What Actually Has to Change

The appealing version of cross-posting is that you write once and it goes everywhere. The honest version is that you write once, and then a handful of specific fields have to change or the publish fails. Knowing which fields those are is most of the work.

The caps that force a rewrite

Character limits are the obvious constraint and the least interesting one, because they are easy to check up front. What matters is the ordering: if you draft against the most generous platform first, every other version becomes a lossy edit you make under time pressure. Draft against the tightest one and the rest are free.

The second-order problem is where the truncation lands. A cap that cuts mid-URL produces a post that looks fine in the composer and is broken in the feed. Any truncation worth shipping happens on a word boundary and never inside a link.

Draft to the tightest limit, expand for the generous ones. Going the other direction turns every publish into an edit under deadline.

A rule that has saved more posts than any validation

Media is where it actually breaks

Text limits are cheap to validate. Media is not — and media is where most failed publishes come from.

The pattern worth internalising: a platform that ignores a field is harmless, a platform that rejects on it costs you the slot. Validate for the rejecting ones, and let the rest quietly discard what they do not use.

The fields that are genuinely per-platform

After a few hundred scheduled posts, the list of things that truly cannot be shared is shorter than it first appears:

• The body text, when a cap forces it. Everything else can usually be shared verbatim.
• The first comment, where a platform treats links in the body as a reach penalty.
• The cover frame for video, because the required dimensions genuinely differ.
• The publish time, which is the one people forget — the right hour on one network is dead air on another.

Everything else — tags, alt text, link previews — can be authored once and allowed to degrade gracefully.

Scheduling is the other half

A limits checklist gets a post accepted. It does not get it published on time. Two things decide that:

Retry behaviour matters more than send-time precision. A publish that fails at 09:00 and silently never retries is worse than one that lands at 09:04. Anything scheduling on your behalf should tell you which of those happened.

And per-account times beat one global time. Posting the same draft to five accounts at the same instant optimises for the scheduler’s convenience, not the audience’s. If a tool makes you choose one time for everything, you will eventually work around it by hand — which is the thing you bought the tool to avoid.

Where this leaves you

Write to the tightest text cap. Validate media against the platforms that reject rather than ignore. Accept that four or five fields will always be per-platform and build the workflow around that instead of pretending otherwise. That is roughly the whole discipline — the rest is remembering to check the limits again next quarter.