Multi-Platform Post Length Checker

About the Multi-Platform Post Length Checker

Every network enforces its own character ceiling: X/Twitter cuts off at 280, Threads at 500, Instagram and TikTok captions at 2,200, Pinterest descriptions at 500, LinkedIn posts at 3,000, YouTube descriptions at 5,000, and Facebook stretches all the way to 63,206. Rather than checking one limit at a time, this tool counts your text once and checks it against all eight simultaneously, turning a row green while you have room, amber once you're past 90% of the limit, and red the moment you go over, along with the exact number of characters remaining (or how many you're over by).

One consistent length metric, applied evenly across all eight platforms

The counter reads text.length once per keystroke and checks that same number against every platform's limit. That's a deliberate simplification worth understanding: real platforms don't all count characters identically. X/Twitter, for instance, historically counts any URL in a tweet as a fixed 23 characters through its t.co link-shortening regardless of the URL's actual length, and some platforms weight non-Latin scripts differently in their own backend counters. This tool doesn't replicate any of that platform-specific logic — it applies one plain, uniform JavaScript string length across the board, which is accurate for ordinary typed text but won't perfectly mirror every platform's internal counting quirks in edge cases like pasted links or complex emoji.

Why the warning color kicks in at exactly 90%, not right at the limit

A row turns amber once your text reaches 90% of a platform's limit — for X/Twitter's 280-character cap, that's 252 characters — rather than waiting until you're actually over. That earlier warning threshold exists because most people don't stop writing the instant they hit a wall; giving a visible heads-up with room still left to trim gives you a chance to shorten the post before you're forced to after the fact.

Rows are built once, then updated in place on every keystroke

The eight platform rows are constructed a single time when the page loads, and each row's key elements (its progress bar, count text, and remaining-characters label) are stored in a lookup object keyed by platform. On every input event, the render function updates those existing elements directly rather than rebuilding the whole row list from scratch — a small efficiency choice that keeps typing responsive even though eight rows are recalculating simultaneously on every character typed, without the browser having to tear down and recreate the same DOM nodes over and over as you type.

The progress bar width is capped so it never overflows visually

Each bar's fill width is calculated as a percentage of the limit but passed through Math.min(100, ...) before being applied, so even if your text is several times over a platform's cap, the bar simply stays filled at 100% rather than trying to render a width greater than its container. The exact overage still shows in the text below the bar ("X characters over limit"), so you don't lose that information even though the bar itself flattens out.

Instagram and TikTok share the same 2,200-character cap, which isn't a coincidence in the code

Both platforms are configured with an identical 2,200 limit in the tool's platform list — that reflects the real caption limits both networks actually enforce, not a placeholder value reused by mistake. Since platform limits do occasionally change as networks update their products, treat every number shown here as accurate as of when this page was written, and double-check against the platform's current help documentation before relying on it for a hard deadline-critical post, especially on a platform you don't post to often.