Slack
Slack pricing, checked August 2026
The one vendor here that bills per active user, which helps more than most people realise.
What it costs
Slack lists Pro at $8.75 per active user per month on monthly billing and $7.25 on annual, and Business+ at $18 monthly and $15 annual, checked on slack.com/pricing on 21 August 2026. Free keeps 90 days of message history. Slack bills only members who took an action within a 28-day period. Polaris includes team chat at no cost.
- Pro
- $8.75 monthly / $7.25 annual
- Business+
- $18 monthly / $15 annual
- Free history
- 90 days
- Checked
- 21 August 2026
Slack plans on both billing bases
Read from slack.com/pricing on 21 August 2026. Slack prints both rates, which is more than most vendors in this cluster do.
- Free$0
- Pro$8.75 / active user / month
- Business+$18 / active user / month
- Enterprise+Contact sales
| Plan | Monthly billing | Annual billing | Gap |
|---|---|---|---|
| Free | $0 | $0 | 90 days of message history, searchable |
| Pro | $8.75 / active user / month | $7.25 / active user / month | $1.50 per user per month, 21% more on monthly |
| Business+ | $18 / active user / month | $15 / active user / month | $3.00 per user per month, 20% more on monthly |
| Enterprise+ | Contact sales | Contact sales | Not published |
Fair Billing is genuinely fair, and worth using
Slack's policy states that members who take an action in Slack at any time within a 28-day period are considered active for billing purposes. If someone you have already paid for goes inactive, Slack adds a prorated credit for the unused time. New members added mid-cycle are charged prorated for the remainder.
That makes Slack the cheapest tool in a typical stack to over-provision and the most expensive to under-audit, because dormant accounts cost nothing but half-active ones cost full price. Compare that with Atlassian, which bills on the highest seat count assigned at any point in the cycle whether or not anyone logged in.
Slack across four team sizes
Straight multiplication at the listed rates. Actual invoices will be lower wherever people go inactive for a full 28-day window.
- 5 active users$43.75 / month
- 10 active users$87.50 / month
- 25 active users$218.75 / month
- 50 active users$437.50 / month
| Team size | Pro, monthly basis | Pro, annual basis | Business+, annual basis | Business+ per year |
|---|---|---|---|---|
| 5 active users | $43.75 / month | $36.25 / month | $75.00 / month | $900.00 |
| 10 active users | $87.50 / month | $72.50 / month | $150.00 / month | $1,800.00 |
| 25 active users | $218.75 / month | $181.25 / month | $375.00 / month | $4,500.00 |
| 50 active users | $437.50 / month | $362.50 / month | $750.00 / month | $9,000.00 |
The three costs a Slack invoice does not show
The 90-day wall on Free
Free keeps 90 days of history. Most teams do not upgrade for features; they upgrade the first time a decision from four months ago cannot be found.
Signal that never becomes work
A request in a thread is not a task. It is a task-shaped message that decays. Polaris turns a Slack message into a prefilled task suggestion with bucket, lane, labels and owner already set, waiting for one click. Signals become suggestions, never silent tasks.
Slack sits on top of the other two bills
Nobody buys Slack instead of a tracker and a docs tool. It is the third subscription across the same headcount, which is why it appears in every stack-cost page in this cluster.
Slack against Polaris
Slack Pro
- $8.75 per active user per month, monthly billing
- Billing by activity, with prorated credits for the inactive
- Where the signal lives, and where it dies
- Team chat only; tasks and docs are separate subscriptions
Polaris
- Team chat included at $0 alongside tasks and docs
- Inbox turns tool signals into prefilled task suggestions
- AI workers you can talk to in the same place as your team
- Roughly $2 per human-equivalent hour delivered, and nothing else
Where to go next
A Slack alternative where the message becomes a task, not scrollback
Slack is where the signal arrives. It is also where the signal goes to be forgotten by Thursday.
Slack vs Microsoft Teams
This is not really a chat comparison. It is a question about which suite you already pay for.
Replacing Notion and Slack
A stack with a writing tool and a talking tool, and no place where a piece of work has an owner and a date.
Replacing Jira and Slack
Engineering teams on Jira and Slack have a tracker, a chat tool, and specs living in ticket descriptions.
Connect Slack to Polaris
Six scopes, no access to direct messages, and a bot that only reads the channels somebody invited it into.
Tool stack cost for a 25-person team
The size where paying monthly instead of annually costs $1,650 a year on its own.
Questions people ask
+Does Slack charge for every member of the workspace?
No. Slack's Fair Billing policy counts a member as active if they took any action within a 28-day period, and adds a prorated credit when a paid member goes inactive. That makes a dormant account free and a barely-used account full price.
+How much more does Slack cost on monthly billing?
About twenty-one percent more on Pro, at $8.75 against $7.25 per active user per month, and exactly twenty percent more on Business+, at $18 against $15. Both figures were read from slack.com/pricing on 21 August 2026.
+Does Polaris replace Slack?
Polaris includes team chat in the free workspace, so it can. Most teams start by connecting Slack instead, which lets the Inbox turn messages into prefilled task suggestions while everyone keeps using Slack. The saving arrives only when seats are actually cancelled.
+What does the Polaris Inbox do with a Slack message?
It proposes a task with bucket, lane, labels and owner already filled in, and waits. Nothing is created until a person clicks. Signals become suggestions, not silent tasks, which is the difference between a helpful Inbox and an unusable one.
+If Polaris chat is free, where does the money come from?
From delivered work only, at roughly two dollars per human-equivalent hour, estimated by a published formula and logged job by job on the worker's work log. Chat, tasks, docs, connections and unlimited human seats cost nothing.
Related
A Slack alternative where the message becomes a task, not scrollback
Slack is where the signal arrives. It is also where the signal goes to be forgotten by Thursday.
Slack vs Microsoft Teams
This is not really a chat comparison. It is a question about which suite you already pay for.
Replacing Notion and Slack
A stack with a writing tool and a talking tool, and no place where a piece of work has an owner and a date.
Replacing Linear and Slack
Issues in one place, everything anyone said about those issues in the other, and nothing written down.
Connect Slack to Polaris
Six scopes, no access to direct messages, and a bot that only reads the channels somebody invited it into.
Tool stack cost for a 10-person team
The size where the free tiers run out on all three products at roughly the same time.
Per-seat pricing and usage pricing charge for different things
One model prices access. The other prices output. Almost every argument about software cost is really about which of those you are buying.
Per-seat pricing
The bill tracks headcount, which is only a proxy for value received.