Slack Problems & Issues

Notification noise is the most repeated complaint on G2: roughly 600 reviews mention excessive notifications in busy channels and large teams, and about 660 say channel management becomes overwhelming. The always-on chat culture pushes people to respond instantly, which hurts focused work.

Slack becomes hard to search once a workspace has years of traffic: results depend on exact keywords, channels you belong to and search modifiers most people never learn. On the free plan anything older than 90 days simply does not appear. Users describe Slack as a place where decisions get lost.

Threads hide replies from the main channel, so people either miss them or avoid threads entirely. Combined with channel sprawl (a top G2 complaint), context gets scattered and important decisions are hard to find later.

On the free plan you can only view and search the last 90 days of messages and files. Since August 26, 2024, Slack also permanently deletes free-workspace data older than one year on a rolling basis, so upgrading later cannot bring it back. Owners can only choose between keeping data for one year or deleting it after 90 days.

Licensing guides consistently describe Enterprise Grid (now sold as Enterprise) as having no downgrade path: workspaces are migrated into the org in full, and moving back to a single Business+ workspace is not a supported self-serve option. Treat a Grid migration as a long-term commitment and confirm exit terms with sales.

On June 17, 2025 Slack raised Business+ from $12.50 to $15 per user/month billed annually ($15 to $18 monthly), justified by bundled AI features and Salesforce integrations. Existing self-serve customers were moved to the new price at their first renewal after August 17, 2025, and turning AI off does not lower the bill.

The old $10/user Slack AI add-on is no longer sold; AI is now bundled by plan. Free and Pro get only basic AI (summaries, huddle notes) and a trial of Slackbot, while AI recaps, translations, file summaries and the full Slackbot agent require Business+ or Enterprise+. Teams that want AI for a few people must upgrade everyone.

Slack's desktop client is built on Electron, which loads a full browser engine. Memory grows with every signed-in workspace and long-running session; Slack's 2019 rewrite cut usage roughly in half, but users with several workspaces still see heavy RAM use next to other Electron apps.

Reviewers on G2 and Capterra report slow replies, difficulty reaching a human, and policies that require the primary workspace owner for many account requests. Free workspaces get only help-center self-service, so most issues must be fixed with in-app troubleshooting tools.

Slack encrypts data in transit and at rest but does not offer end-to-end encryption; customer-managed keys (EKM) are an Enterprise+ add-on. In May 2024 Slack faced backlash because its privacy principles let it use customer data for ML models by default, with opt-out only by the workspace owner emailing Slack. Slack clarified it does not train its generative AI LLMs on customer messages.

On February 26-27, 2025 a major outage stopped messages from sending or loading, broke workflows and API events, and took most of a day to recover; Slack attributed it to database shard problems. Shorter incidents (blank screens, failed loads) appear on slack-status.com several times a year and halt teams that run entirely on Slack.

Missed notifications are a long-running complaint on every platform. On Android, battery optimization and Google Play Services settings delay pushes; on desktop, Focus/Do Not Disturb and OS permissions block them. Slack itself shipped a Windows desktop release in February 2026 where sounds played but pop-ups never appeared, fixed by a rollback.