Mastodon Post Preview (Live 500-Character Toot Mockup)

Mastodon is the rare network with no algorithmic feed and no caption fold — your toot appears in full, in the order people you follow posted it. That changes the writing job. There’s no “…see more” cutoff to outsmart and no hook tax to pay to a ranking model; the trade is that there’s also no second chance to surface a post that didn’t land. Every one of your 500 characters is visible, so every one should pull its weight.

This preview shows the entire toot for exactly that reason — the card never collapses your text. The counter under the textarea reads from the same verified limits dataset as our Mastodon character counter, so the 500-character default it enforces can’t drift from the real number. The default is what to write against even though federation complicates the ceiling (more on that below).

Three cues do most of the work, and the preview renders all three. The avatar is a rounded SQUARE, not a circle — the single most recognizable Mastodon trait. The favourite action is a STAR, not a heart, sitting between the boost (the two-arrow reblog) and the bookmark in the footer. And the header carries a Public globe with a short relative timestamp instead of a verified checkmark, because Mastodon has no verification badges. Links, mentions, and hashtags render in Mastodon’s accent “blurple.”

What the card doesn’t do is pass as a real screenshot. It uses your own placeholder name and @handle, never a real account, with a non-affiliation disclaimer under it. The point is to test how your name, handle, image, and text sit together — a faithful approximation, not a forged capture.

Mastodon’s 500 is a default, not a universal law: it’s open source and federated, so instance admins can raise the limit, and some communities run into the thousands. The 500-character default stays the safe number to write against — especially when scheduling through tools that validate against standard Mastodon — so that’s what this preview counts. Two friendly counting quirks the preview doesn’t simulate but worth knowing: every link counts as a flat 23 characters regardless of length, and only the @username part of a mention counts (the instance domain is free), so link- and mention-heavy toots have more room than a raw character count suggests.

When the toot reads well, the remaining job is publishing it on schedule. SocialKit posts to Mastodon alongside ten other networks and shows each one’s limit as you compose — so a 500-character Mastodon toot and a 280-character X version are written as siblings, not afterthoughts. The Download PNG button draws a simplified version of this card in your browser with the Canvas API, for approvals and content calendars.