Alternatives to Slack
Slack alternatives worth switching to
The best Slack alternatives are Mattermost (open source, self-hostable, closest to Slack in feel), Zulip (threading that genuinely scales past a few hundred people), and Microsoft Teams if you already pay for Microsoft 365. Switch if per-user pricing or the message-history limit is the problem — stay on Slack if its app integrations are load-bearing for your workflows.
Pricing verified 2026-07-28 · we re-check quarterly ·
how we compare
Why people leave Slack
- Per-user pricing across a team where many members barely post
- The free tier's message-history limit hiding old decisions
- Wanting conversations on infrastructure you control
- Compliance or data-residency requirements a hosted vendor cannot meet
The alternatives
1 Mattermost open source
Best for: Self-hosting a Slack-shaped workspace
Pricing: Free and open source. Your cost is hosting — roughly $5–20/month on a small VPS, or nothing on hardware you already own — plus your own time for updates and backups. Paid self-hosted and cloud tiers add enterprise features. source
Strengths
- Looks and behaves close enough to Slack that migration is painless
- Self-host and keep every message forever with no history limit
- Strong compliance story — popular in defence and regulated sectors
Trade-offs
- Fewer third-party integrations than Slack
- You own hosting, upgrades and backups
- Mobile apps are less polished
Verdict: The default self-hosted answer. If unlimited history and data control are the drivers, this is the one.
source code ↗ 2 Zulip open source
Best for: Teams drowning in Slack threads
Pricing: Free and open source. Your cost is hosting — roughly $5–20/month on a small VPS, or nothing on hardware you already own — plus your own time for updates and backups. A hosted cloud tier with a free plan is also offered. source
Strengths
- Topic-based threading that genuinely works at scale — the standout feature
- Catching up after time away is far less painful than in Slack
- Free for open-source and academic projects
Trade-offs
- The threading model takes a week to get used to
- Smaller ecosystem
- Feels less immediate than Slack for quick chatter
Verdict: The best choice for large or asynchronous teams. The threading model is a real improvement, not a gimmick.
source code ↗ 3 Rocket.Chat open source
Best for: Customer-facing chat as well as internal
Pricing: Free and open source. Your cost is hosting — roughly $5–20/month on a small VPS, or nothing on hardware you already own — plus your own time for updates and backups. Paid enterprise tiers and a cloud option are also sold. source
Strengths
- Handles internal chat and customer-facing livechat in one system
- Highly customisable and self-hostable
- Omnichannel features included
Trade-offs
- Broader scope means more configuration
- Interface is busier
- Upgrades need care on self-hosted instances
Verdict: Worth it when you want team chat and customer chat under one roof. Otherwise Mattermost is simpler.
source code ↗ 4 Microsoft Teams
Best for: Organisations already paying for Microsoft 365
Pricing: Included with most Microsoft 365 business plans; a free tier exists. Prices change often, so check the vendor's current pricing page before deciding. source
Strengths
- Effectively free if you already pay for Microsoft 365
- Deep Office, SharePoint and calendar integration
- Video conferencing built in
Trade-offs
- Widely disliked for performance and interface
- Poor fit for organisations not already in Microsoft's world
- Less pleasant for developer-style chat
Verdict: Hard to argue against on cost if you already pay for Microsoft 365. Nobody switches to it for the experience.
Don't switch if…
- Your workflows depend on Slack integrations and apps
- The team is small enough that per-user pricing is not painful
- Nobody will own a self-hosted server
- Culture and adoption matter more than the bill — a chat tool nobody likes is worthless
We say this on every page. A comparison that never recommends staying put is an
advert, not a comparison.
Questions people actually ask
Who is Slack's biggest competitor?
Microsoft Teams by a wide margin on user numbers, largely because it is bundled with Microsoft 365. Among tools people actively choose rather than inherit, Mattermost and Discord are the most common alternatives.
What is the best free alternative to Slack?
Mattermost if you can self-host — free with unlimited message history, which is the specific limit that pushes teams off Slack's free tier. Zulip's cloud has a free plan, and Discord is free though aimed at communities rather than companies.
Does anyone use Slack anymore?
Yes — it remains the default in tech companies and startups, and its integration ecosystem is still the strongest. Microsoft Teams leads on raw user count mostly through bundling rather than preference.
What competes with Slack?
Microsoft Teams and Google Chat among the bundled suites; Mattermost, Rocket.Chat and Zulip among open-source self-hosted options; Discord for community-style teams.
Is there a cheaper alternative to Slack?
Self-hosted Mattermost or Zulip cost only your server — commonly $5–20 a month for the entire team regardless of headcount. Microsoft Teams is effectively free if you already pay for Microsoft 365.