In short: on Slack's free plan you can only see messages and files from the last 90 days, and data older than a year is deleted. You can upgrade, export your history regularly, or move the team to a tool that doesn't limit history this way. The right call depends on team size and how often you dig up old decisions.
What disappears
The limit covers everything: channel messages, direct messages and files. After 90 days they are hidden and won't show up in search. After a year they are gone for good (per Slack's plan comparison).
Option 1: upgrade
Simple, but paid Slack plans are billed per active user. Invite clients and contractors and the bill grows faster than the team does.
Option 2: export
On the free plan, owners can export public channels only, as JSON, with links to files (not the files) from the last 90 days. Private channels and DMs aren't included (per Export your workspace data). It's a backup, not a working archive: you can't search it in context or reply to an old thread.
Option 3: switch tools
When comparing alternatives, check history and search limits, per-user vs per-workspace pricing, guest permissions, and where your data is stored — that matters under GDPR.
How to decide
Ask your team: how often last month did someone look for something older than three months? Rarely — a quarterly export is enough. Regularly — the limit is already costing you time.
FAQ
Does upgrading bring back old messages?
Yes, for anything not yet deleted: per Slack, messages and files beyond the 90-day limit are revealed when you upgrade. Data older than a year has already been deleted and can't be recovered (Feature limitations on the free version).
Can you do voice calls on free Slack?
Yes, but free huddles are one-to-one only, and you can connect up to 10 apps, per Slack's plan comparison.
Sources (as of October 2026), Slack Help Center: plans and features, export your workspace data, free version limitations.
Comparing alternatives? See Devana pricing: you pay for the whole workspace, not for each person.