Can I sell our old Slack messages, and how do I export Slack history?

Often, yes. Most providers that license company records name Slack, and they say the value is in threads where a question, the replies and the decision sit together. Two limits come first: since August 26, 2024, Slack may delete Free workspaces’ messages older than a year, and a standard export covers public channels only.

Is Slack history what AI buyers want?

Yes, when it holds working conversations, the threads where people ask, answer and decide. As of October 2026, providers describe it this way:

• Polyshares, in its Slack export guide: “Slack channels hold the working record of how a team makes decisions. A question, the replies and the outcome sit in one thread with names and timestamps”.
• Troveo lists Slack under chat and asks for “Complete conversation threads with participants and replies intact”.
• Nyne asks for “Full conversation histories, threads, participants, and reply structure preserved intact”.
• Telegraph Lab (affiliated with this site) lists Slack under work conversations: “Team discussions, customer support threads, and the decisions behind a project”.

Links to other systems raise the value. Troveo’s guide for closing startups says “a ticket linked to its Slack thread, its Jira issue and the pull request that closed it is worth more than any of those on its own”. The same guide says “The messy parts (the bug that took three tries, the escalation, the reverted release) are what make the record useful”, so there is no reason to tidy channels before a buyer has scoped them. By that measure, a channel where a team works through customer problems carries more than one that only relays automated alerts.

Polyshares’ guide asks owners to report Slack in messages, with the years in use and the number of seats, so have that count ready.

Has anyone been paid for Slack history?

Yes, mostly companies that had closed. Forbes reported in April 2026 that cielo24, a transcription company, sold 13 years of Slack messages, Jira tickets and email through the wind-down firm SimpleClosure for “hundreds of thousands of dollars” when it shut down, and that SimpleClosure had handled nearly 100 deals for closing companies in a year, typically paying $10,000 to $100,000 each. Those are closing-company sales, not prices for an operating business. Are AI companies really paying businesses? sets out the wider evidence, and How much is my company’s data worth? lays the published ranges side by side.

How far back does our Slack go?

A paid workspace keeps everything “for the lifetime of your workspace by default” unless an owner set a shorter policy. A Free workspace shows only the last 90 days, and since August 26, 2024 Slack may delete messages and files more than a year old “on a rolling basis”.

Slack retention and export, by planChecked October 4, 2026

Slack retention and export, by plan. Checked October 4, 2026

	Free	Pro	Business+	Enterprise+ (help-center tabs say 'Enterprise'; org-based plan historically sold as Enterprise Grid)
Default retention	Free workspaces store messages and files for at most one year; anything older than a year is permanently deleted.[1] as of October 4, 2026	On all paid plans (Pro, Business+, Enterprise+), messages and files are kept for the lifetime of the workspace unless an owner sets a shorter retention policy.[2] as of October 4, 2026	On all paid plans (Pro, Business+, Enterprise+), messages and files are kept for the lifetime of the workspace unless an owner sets a shorter retention policy.[2] as of October 4, 2026	On all paid plans (Pro, Business+, Enterprise+), messages and files are kept for the lifetime of the workspace unless an owner sets a shorter retention policy.[2] as of October 4, 2026
Configured retention	Workspace Owners on Free can only pick between keeping messages/files for one year or deleting them after 90 days; no custom periods.[3] as of October 4, 2026	Workspace Owners can choose never delete (with or without saving edit history) or a custom timeline; file retention is set separately; owners can let members override retention for private channels and DMs.[2] as of October 4, 2026	Same retention options as Pro: never delete (with/without edit logs) or custom timeline, separate file retention, optional member overrides for private channels/DMs.[2] as of October 4, 2026	Org Owners can set org-wide message and file retention policies applying to every workspace; Workspace Owners adjust retention only if Org Owners allow; legal holds override retention.[2] as of October 4, 2026
Visible vs retained	Free workspaces can view/search only the last 90 days; messages 90 days to 1 year old are hidden (revealed on upgrade), and since August 26, 2024 content over one year old is deleted on a rolling basis. Before Aug 2024 (from the Sept 1, 2022 change) older content was hidden but kept.[3] as of October 4, 2026	No visibility cap on paid plans: full message history is searchable. A member's deleted message cannot be brought back ('Deleting a message is permanent'), and anything deleted by a retention policy is permanently gone. With 'Never delete messages — save edits', Slack says it will 'keep all messages and track message edits and deletions'.[2, 4] as of October 5, 2026	Full history visible. A member's deleted message cannot be brought back, and retention deletions are permanent; the 'Never delete messages — save edits' setting tracks edits and deletions. No legal holds on Business+ to preserve content against edits/deletes.[2, 4] as of October 5, 2026	With a legal hold, members' messages and files are preserved regardless of retention settings or member edits/deletes, while remaining subject to normal visibility in the client.[5] as of October 4, 2026
Admin rights needed	Workspace Owners and Admins can run the standard export of public channels; only Workspace Owners set retention.[6, 7] as of October 5, 2026	Workspace Owners and Admins can export public channels; retention settings are set by Workspace Owners.[6] as of October 4, 2026	Workspace Owners and Admins can export public channels; only Workspace Owners can apply for and use the all-conversations export tool, and the application requires Primary Owner approval.[8] as of October 4, 2026	Org Owners/Admins and members with the Export Admin system role can export; self-serve export tools must be requested from Slack Support; Discovery API is enabled by Primary Org Owner/Org Owners.[8] as of October 4, 2026
Export method	Standard export covers public channels only. Owners may apply to Slack to export private channels and DMs, but Slack rejects applications absent valid legal process, member consent, or a legal requirement/right.[6] as of October 4, 2026	Pro has only the public-channel export self-serve; exporting private channels and DMs requires applying to Slack under limited circumstances (legal process, member consent, or legal requirement).[6] as of October 4, 2026	Once approved, Workspace Owners get a self-serve tool to export all channels and conversations including private channels and DMs, and can schedule recurring weekly or monthly exports.[6] as of October 4, 2026	Exports by conversation type, member, or workspace; export of all conversations a single user is in; plus the Discovery API for approved third-party eDiscovery/archiving/DLP apps.[9] as of October 4, 2026
Export formats	Export is a ZIP of JSON files (a folder per channel, one JSON file per day) with file links rather than file binaries.[10] as of October 4, 2026	ZIP of JSON (per channel per day) plus users.json, channels.json, integration_logs.json, canvases.json; files are links back to Slack.[10] as of October 4, 2026	JSON exports (ZIP, folder per conversation, file per day; groups.json for private channels, dms.json for DMs); channel audit reports as CSV; files as links only.[6] as of October 4, 2026	Standard exports are JSON; single-user exports can be JSON or TXT (a TXT file per channel/DM); Discovery API returns files via direct download links.[10] as of October 4, 2026
Plan limits	Free-plan exports only include file links from the last 90 days, and data more than a year old is not included.[8] as of October 4, 2026	Plans comparison shows no 'Data exports for all messages' for Pro (only Business+ and Enterprise+).[1] as of October 4, 2026	Business+ includes data exports for all messages but not per-user exports, legal holds, or the Discovery API (Enterprise+ only).[1] as of October 4, 2026	Enterprise org exports cannot be imported into other Slack workspaces; Discovery API use is limited to eDiscovery, archiving and DLP.[8] as of October 4, 2026

What Slack holds: Channel messages, DMs and files of custodians (Enterprise+ only), Edited and deleted message versions, Excluded from holds.

The table shows the rules; what is left depends on your workspace’s own plan history:

• On Free now: you hold about a year at most. Slack says “When you upgrade, your messages and files beyond the 90-day limit will be revealed”, but an upgrade cannot bring back what the one-year rule already deleted.
• Upgraded from Free after August 26, 2024: expect history to start about a year before the upgrade, since Slack could delete anything older while you were on Free.
• On a paid plan since before August 26, 2024: the Free plan’s deletion never applied to you; only your own retention settings did.
• An owner set a retention policy: what it removed is gone. Slack says “Data deleted according to your retention setting is permanent”, and owners on paid plans can let members override retention for private channels and DMs, so those can reach back less far than public channels.

To check, scroll to the first message in your oldest working channel, ask a Workspace Owner what the retention setting is, and look at your billing history for the date you left Free. Write that first-message date in your data inventory, not the date you opened the workspace. While you decide, leave retention as it is and do not move back to Free, which would put anything over a year old under the Free plan’s deletion again.

Can we export private channels and DMs, or only public channels?

Public channels only, unless your plan and Slack’s approval allow more. A Workspace Owner or Admin can export public channels on every plan; on Enterprise plans, so can an Org Owner or Admin, or a member given Slack’s Export Admin role. Private channels and direct messages are where the plans part ways, and the table above shows which plan allows what. Four points it cannot show:

• Free and Pro need a reason Slack accepts. An owner can apply, but Slack approves only with “(a) valid legal process, or (b) consent of members, or (c) a requirement or right under applicable laws”. Whether a licensing deal fits any of these is for Slack and your lawyer to say, so on Free or Pro, plan the scope around public channels unless members consent.
• Business+ is not automatic either. The application needs the Primary Owner’s approval, and Slack’s Support team emails before proceeding. Once approved, Slack says “Each Workspace Owner must ensure that (a) appropriate employment agreements and corporate policies have been implemented, and (b) all use of data exports is permitted under applicable law.” Do I have to tell my employees? covers the documents to check.
• Files are not in a standard export. It carries links back to Slack, and “If you delete a file, or the channel or workspace it was shared in, the file will no longer be accessible via the file link in your export.” If you are closing the company or leaving Slack, download the files you want before anything is deleted.
• Shared channels carry another company’s posts. For Slack Connect channels, links to files in private shared channels or DMs are included only if a member of your workspace shared them. Posts in a shared channel include the other company’s staff; leaving out records explains how to keep such a channel out of scope.

The admin steps for each export are in How much work is it to license company data?

Can a buyer connect to our Slack instead of us exporting it?

Some providers offer to, but Slack’s API terms limit what an outside app may do with what it reads. The terms, effective October 10, 2025, say a developer offering an app to others outside its own organization may not “use API Data to train a large language model”, nor “bulk export Slack message and file data except where expressly allowed by an additional agreement, such as by Applications using the Discovery API for approved security and compliance use cases”. API Data means messages, files, metadata and other data obtained from Slack’s APIs. The Discovery API itself is limited to security and compliance uses, in particular eDiscovery, archiving and data loss prevention, on Enterprise plans.

Your own export and a buyer’s connection are governed by different documents:

• Your own export is made by a Workspace Owner or Admin with Slack’s export tool, not through an app, and Slack’s export pages set its conditions (above). Whether your workspace agreement with Slack says more about how you may use exported data is a question for your lawyer.
• A buyer’s connection is an app installed in your workspace that reads through Slack’s APIs, and the API terms bind that app’s developer.

Ask any provider that proposes to connect whose app it is, whether it reads through Slack’s APIs, and whether it holds an additional agreement with Slack that covers this use. Is it legal to sell company emails and records? puts platform terms alongside your other contracts.

What happens to former employees’ Slack messages?

They stay. Slack says deactivated members are not notified, “nor are their messages or files deleted”, and deactivation leaves profile information such as full name and display name in place. A leaver’s posts therefore remain in every channel they used and in any export of those channels. Their DMs come out only where private conversations can be exported, and Enterprise plans can also export all the conversations of a single member.

Email works the other way. In Microsoft 365 a removed user’s mail is permanently deleted after 30 days unless a hold was applied, and in Google Workspace a deleted user’s mail can be restored for only 20 days. Because a leaver’s name stays on every Slack post, redaction matters. The sample tool replaces names from Slack profiles with consistent labels, and what “anonymized” means covers how providers handle the rest. Whether former staff need notice, or their consent, is covered in is it legal.

Which buyers say they take Slack data?

Sixteen of the 25 buyers and intermediaries Data Licensing Report tracks name Slack on their own pages as a source they take or help license, as of October 2026. Not all of them pay you: introducers match you with a buyer, and wind-down platforms work mainly with companies that are closing.

Provider	What it is	What its own page says
Avelence	Introducer; does not buy data	Slack among the tools whose records it helps license (source)
Corpus	Licenses directly	Slack among the systems it licenses from (source)
Handshake AI	Licenses directly	Slack in its “Examples of sources we buy” (source)
License My Data	Introducer	“Email, calendar, Slack and Teams” under workplace records (source)
Mercor	Licenses directly	Slack among the tools you connect (source)
Miro Advisory	Introducer; does not buy data	Slack among the communication systems it covers (source)
Nyne	Licenses directly	Slack under chat and messaging (source)
Polyshares	Licenses directly	Slack first in its list of operational data (source)
Replay	Licenses directly	Slack among sources on its page for AI buyers (source)
Scale AI	Licenses directly	Slack under chat and messaging (source)
Scrimdata	Licenses directly	“inboxes, Slack workspaces, ticket queues” (source)
Sell My Business Data	Introducer	Slack under work conversations (source)
SimpleClosure (AssetHub)	Wind-down platform; said on September 3, 2026 it also takes operating companies	Slack among its workspace-data platforms (source)
Sunset	Wind-down platform; buys from startups that are closing	“Slack threads, product specs, and code repositories” (source)
Telegraph Lab	Licenses directly	Slack under work conversations (source)
Troveo	Licensing agent	Slack under chat and messaging (source)

Two other providers describe record types rather than systems: Appen lists “Messaging & meetings” as a typical source of decision records, and micro1 asks for procedures and process documents and names no chat system (Appen, micro1). HUD, which runs the DataVendor listing service, mentions Slack threads only as context that makes a codebase worth more, and its packaging steps do not include a Slack export (HUD). The buyers directory compares all of them on the same fields.

What does the sample tool read from a Slack export?

The export .zip exactly as Slack delivers it, or the same files unzipped into a folder. Data Licensing Report’s free sample tool reads the member and channel lists, the private-channel and DM lists when your export includes them, and the daily message files. It counts channels, threads, replies, people and the files that messages refer to, and messages by month; it does not fetch the files themselves. It then replaces names from Slack profiles with consistent labels, so the same person reads as the same label in every thread, and picks a small set of threads spread across the years for you to review.

The result stays on your computer: the inventory a buyer asks for first, and a redacted sample you can choose to share. If your company also runs on email, the Google Workspace and Microsoft 365 pages cover those exports, and the guide puts every step in order.