Paste or type your Slack post to see how many characters you have used out of 40,000, and how many are left.
0 / 40,000
40,000 characters remaining
The count is by code points, the same as fanout uses before publishing. Slack's own counter may differ slightly. Details are in the character limits guide.
Slack messages can run far longer than a social post, and fanout lets your Slack draft use up to 40,000 characters instead of trimming it to fit a tweet-sized limit. Connect a channel, write your update, attach a file or image, and schedule it to post at the time you pick; each connected Slack account maps to one channel. Comments and analytics aren't available for Slack yet, since fanout treats it as a broadcast channel rather than a social network with its own metrics API.
Schedule posts to Slack · Count against all 15 networks
Write one draft, publish to every network. Card required, cancel anytime, no charge during the trial.
fanout enforces 40,000 characters per Slack post, counted as Unicode code points. A post can carry up to 4 images.
Yes. A simple emoji is one code point, so it counts as one here. Emoji built from several parts (skin tones, flags, family emoji) are several code points and count as several. Slack may weight characters differently, so leave a little room if you are close to the cap.
fanout flags the post as too long for Slack before it publishes, so nothing is cut off silently. Shorten it, or write a shorter version for Slack and keep the long one for the other networks.
It is the count fanout uses when it checks a post, based on Slack's documented limit as of 2026-10-25. Networks change limits and count some characters differently, so treat a post within a few characters of the cap as unconfirmed until Slack accepts it.