On Slack’s Free plan you can read and search the last 90 days of messages and files. Anything older is hidden, and once it is more than a year old Slack deletes it for good. Those two sentences cover most of what a small team needs to know, but the way the limit behaves — quietly, with no warning in the channel — means most teams only discover it when they go looking for something that is no longer there. This post explains what the limit actually does, what it tends to hide, the three honest ways to deal with it, and a fourth option for teams that would rather not manage it at all.
What the 90-day limit actually does
Slack’s help centre is precise about this, and it is worth reading the exact wording rather than the folklore. A free workspace can view and search messages and files from the last 90 days. When the workspace reaches the limit, Slack starts hiding older messages and files to make room for new ones. Messages and files more than one year old are permanently deleted — a rolling deletion Slack began on 26 August 2024, after which a free workspace no longer keeps anything for its lifetime.
The gap between those two dates matters. For days 91 to 365 a message is hidden, not gone: Slack’s own notice says the remaining 275 days “will become available should you upgrade to a paid plan”. After day 365 there is no path back; the FAQ on the same page says plainly that it will not be possible to restore messages and files once deletion occurs.
| On the Free plan | What Slack’s help centre says |
|---|---|
| Visible and searchable history | The last 90 days of messages and files |
| Days 91 to 365 | Hidden; restored if the workspace upgrades to a paid plan |
| Older than one year | Permanently deleted on a rolling basis; cannot be restored |
| Retention setting | Keep for one year, or delete after 90 days (Workspace Owners) |
| Exports | Public channels only; file links from the last 90 days; no scheduled exports |
| Apps | Up to 10 third-party or custom apps |
Two details catch people out. The limit covers files as well as messages — PDFs, screenshots, clips, the signed contract someone dropped into #general. And retention applies to pinned and saved messages too, so pinning the onboarding checklist to a channel does not protect it.
What it hides from a small team
A chat tool is where a small company thinks out loud, and the valuable part of thinking out loud is being able to find it later. Ninety days is shorter than almost everything that matters: a hiring round, a client engagement, a quarter, a product cycle. The things that go missing are predictable.
- Why a decision was made. The thread where you chose a vendor, dropped a feature or agreed a price is the first thing a new hire asks for and the first thing to vanish.
- Client context. A shared channel with a client holds the brief, the change requests and the “yes, go ahead” — and the invoice dispute arrives in month five.
- Operational detail. Which account the domain renews from, who holds the signing key, what the on-call rota was when the incident happened. (Credentials should never have been in chat in the first place; how to share team passwords safely covers that.)
- The onboarding trail. Everything a new starter was told in their first week is gone before their probation review.
The failure mode is quiet. Nothing in a channel says “this is about to disappear”, search simply returns fewer results each month, and the person who notices is usually the one who needed the answer most.
Fix 1: set retention to a year, not 90 days
Free workspaces have a retention setting with two options: keep messages and files for one year, or delete them after 90 days. If a Workspace Owner has chosen the 90-day option — or chose it years ago and forgot — then the hidden messages are not merely hidden; the setting deletes whatever the visibility limit has hidden, and there is nothing to recover on an upgrade. Slack runs the deletions once a day, so a change takes effect quickly.
- As a Workspace Owner, open Admin in the sidebar, then Workspace settings.
- Next to Data retention, click Expand and choose the one-year option for messages.
- Do the same for File history and for Canvas and list history — each has its own 90-day-or-one-year setting.
- Save, review and confirm. Then put the date in your calendar: the year starts counting from each message, not from today.
This is the cheapest fix and the one most teams have not done. It does not bring anything back into view — the 90-day window is fixed on the Free plan — but it keeps the hidden nine months intact, which is what makes the third fix possible.
Fix 2: export on a schedule, by hand
Free workspaces can export data, and the export is the only copy of a conversation that survives the one-year deletion if you never upgrade. Be clear about what it contains, because the scope is narrower than people assume. On the Free plan an export covers public channels only — messages and file links, as JSON. Private channels and direct messages are not included (that export type starts at Business+ and needs an application), file links only go back 90 days, and the scheduled weekly or monthly export is a Business+ feature too.
So “on a schedule” on the Free plan means a calendar reminder. Every 80 days or so, a Workspace Owner opens Admin → Workspace settings → Security → Import & export data → Export, picks the date range, starts the export and downloads the ZIP when the email arrives. Store it somewhere with its own access control and search — a shared drive, or Filespace if you are on Orbiz — and name it by date range.
The practical consequence is a rule for the team: decisions go in public channels. A decision agreed in a DM or a private channel will not be in the export, which means it will not exist in a year.
Fix 3: upgrade before the year is out
If the hidden history is worth money to you, the honest answer may be to pay for it. Slack’s Pro plan was $7.25 per user a month billed annually ($8.75 billed monthly) and Business+ $15 ($18) when we read the pricing page on 6 October 2026. Upgrading restores the hidden 275 days — provided Fix 1 was in place and they were kept rather than deleted — and from then on messages are kept according to the retention period you choose, including for the lifetime of the workspace.
The arithmetic for a team of ten on Pro annual billing is $870 a year; for twenty-five it is $2,175. If your team lives in Slack’s integrations, uses huddles for calls every day and has Slack Connect channels with customers, that is a reasonable price for the tool you already use and the history you already have, and you should stop reading here. The timing is the only trap: an upgrade restores what is hidden, never what has been deleted, so the decision has to be made before the oldest message you care about turns one.
Whichever you choose: keep a decisions log
None of the three fixes changes the underlying problem, which is that a chat message is a poor place to keep a decision. A thread is where a decision is made; the record of it belongs somewhere that is not subject to anyone’s retention policy — a short, dated entry saying what was decided, by whom, and why, with a link back to the thread while it still exists.
The tool matters less than the habit. A shared document works. A page per quarter in Notely works, and has the advantage of sitting behind the same login as the rest of the company’s tools. What does not work is “it’s in Slack”, because after 90 days it is not.
The fourth option: chat inside your business software
The fourth option is to run chat as one part of the software the company already pays for, rather than as a separate per-seat subscription with its own retention rules. That is what Huddl is: Orbiz’s team chat, included for every member in the one flat price per organisation — from $99 a month for up to 10 people on annual billing, with every other Orbiz tool in the same price. It has public and private channels, direct messages and threads, and search across every conversation you belong to, with filters for sender, channel, date and messages with files. A client or contractor can be invited as a guest by email and sees only the channels they were invited to. Orbiz’s published position is that there is no history limit on any plan: messages are kept for as long as your organisation keeps them.
It is not the right choice for everyone, and the gaps are real. Huddl has no voice or video calls in this release, so a team that depends on huddles needs Slack or a separate calling tool. It has none of Slack’s app directory. And it only makes sense if you want the rest of the platform — HR, attendance, projects, files — because that is what the flat price buys. The feature-by-feature comparison is on Orbiz vs Slack, and the wider team chat shortlist, including Microsoft Teams, Google Chat, Mattermost and Rocket.Chat, is on the team chat shortlist. For the cost side of a stacked per-seat bill, see the hidden cost of eight SaaS subscriptions.
A twenty-minute checklist
- Open Admin → Workspace settings → Data retention and confirm messages, files and canvases are set to one year, not 90 days.
- Run a public-channel export today and store the ZIP outside Slack with the date range in its name.
- Put an export reminder in the calendar every 80 days, assigned to a named Workspace Owner.
- Tell the team that decisions go in public channels and in the decisions log, not in DMs.
- Find the oldest conversation you would pay to keep and note the date it turns one year old — that is your upgrade-or-move deadline.
- Review the app list against the 10-app limit while you are in the settings.
Sources
Slack’s limits, retention options and export scope are from four pages in Slack’s help centre, read on 9 October 2026: Usage limits for free workspaces, Updates to message and file history on free workspaces, Customize data retention in Slack and Export your workspace data. Plan prices are from Slack’s pricing page, read on 6 October 2026, in US dollars. Orbiz prices are on the pricing page.
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