---
title: "Slack specs and limits: text, media, daily cap"
url: "https://get1post.com/platforms/slack/specs.md"
canonical_url: "https://get1post.com/platforms/slack/specs"
last_updated: "2026-10-26"
type: "reference"
summary: "Every text, media and posting rule 1Post checks for Slack, with the network's own page cited and the date read where we read one."
related: ["https://get1post.com/platforms/slack.md", "https://get1post.com/data/posting-limits.md", "https://get1post.com/tools/posting-limits.md"]
---

# Slack specs and limits: text, media, daily cap

Every text, media and posting rule 1Post checks for Slack, with the network's own page cited and the date read where we read one.

Slack text is limited to 4,000 characters, counted by code points. This page lists every text, media and posting rule 1Post checks for Slack: counts, sizes, lengths, threads and the daily cap. Where Slack publishes a figure on its own page we cite it with the date we read it.

## What 1Post checks for Slack

| Rule | What 1Post checks |
| --- | --- |
| Text limit | 4,000 characters, counted by code points |
| Media accepted | Text only |
| Threads | No |
| First comment | No |
| Posts per day, per connected account (1Post) | 100 |

These are the limits 1Post applies in the composer, so a post that passes is not refused for them when it is sent. A network can still refuse a post for reasons outside these rules, such as its content policies.

## What Slack publishes

| Fact | Source |
| --- | --- |
| Slack suggests keeping message text to 4,000 characters for best results and truncates messages over 40,000. | [Slack developer docs: chat.postMessage](https://docs.slack.dev/reference/methods/chat.postMessage), read 2026-10-26 |

## Questions

**How is Slack text counted?**

Slack text is counted by code points. The [character counter](https://get1post.com/tools/character-counter.md) applies the same rule.

**Where do these Slack limits come from?**

They are the limits 1Post checks before a post is sent. Figures the network publishes on its own page are cited above with the date read; the rest are checks 1Post sets.

**How often is this page updated?**

When a network changes a rule or we read a newer figure, the page changes with it. The date at the top shows the last change.

## Sources

- [Slack developer docs: chat.postMessage](https://docs.slack.dev/reference/methods/chat.postMessage), read 2026-10-26

## Related

- [Schedule Slack posts: formats, limits, setup](https://get1post.com/platforms/slack.md)
- [Social media posting limits by network, dated](https://get1post.com/data/posting-limits.md)
- [Social media posting limits table, every network](https://get1post.com/tools/posting-limits.md)