Slack Alternatives for Small Teams: Free and Open-Source Options Worth Considering

Why small teams feel the Slack squeeze

Slack's free plan limits message history, and its paid plans charge per seat — a structure that scales comfortably for large organisations but can feel disproportionate for a five- or ten-person team. On top of the cost question sits the performance question: the official Slack desktop client is built on Electron, which embeds a full Chromium browser in every window. On a modern machine with plenty of RAM it is largely invisible; on older hardware, or when you are running several other Electron apps at the same time (VS Code, Figma, Notion), the memory pressure becomes noticeable.

Neither of these problems is unique to Slack — they apply to much of the modern SaaS messaging landscape. So the search for alternatives usually involves trading off some combination of price, self-hosting complexity, feature completeness, and client efficiency.

The main categories of alternatives

Slack alternatives for small teams tend to fall into three buckets.

Free tiers of commercial services. Tools like Discord, Google Chat, or Microsoft Teams offer free plans with meaningful limitations. Discord is surprisingly capable for small technical teams; Teams is already included in many Microsoft 365 subscriptions. The tradeoff is that you are still running someone else's infrastructure and, in most cases, another Electron or web-wrapper client.

Self-hosted open-source platforms. Mattermost and Rocket.Chat are the most mature options here. Both offer a Slack-like channel structure, file sharing, and integrations. You control the data, the retention, and the upgrade cycle. The cost in money is low; the cost in operational time is real — someone has to run the server, handle updates, and manage backups. For a small team without a dedicated sysadmin, that overhead deserves honest consideration before committing.

Native or lightweight clients for Slack itself. If your team is already on Slack — perhaps because clients or external collaborators require it — the question is not which platform to switch to but which client to use. This is where msga fits.

Using Slack more efficiently with a native client

msga (Make Slack Great Again) is a free, open-source Slack desktop client built in C++/Qt6 — the same framework used by Telegram Desktop. It connects directly to Slack's API rather than wrapping the website in a browser window, so it starts in under a second, idles near 0% CPU, and uses a fraction of the memory the official client requires (roughly 60–100 MB compared to the 1–2 GB or more the Electron client can consume).

This matters most in two scenarios common to small teams: older or modest hardware that simply cannot spare the memory, and developer workstations where every megabyte saved from the chat client is a megabyte available for compilers, containers, or local databases.

msga is licensed under GPL-3.0 and runs on Linux, macOS, and Windows. Because it is a native client rather than a full platform, it does not replace Slack — your team's existing workspace, channels, and integrations remain exactly as they are. Some Slack features are still on the roadmap for msga, so teams that rely heavily on Slack's more advanced functionality should review the project's current state on GitHub before switching their day-to-day workflow.

Comparing the main options side by side

What actually matters for a small team's decision

Before committing to any platform migration, it is worth working through a short checklist.

External collaboration. Do your clients or contractors already use Slack? Switching your internal platform does not help if you spend half your day in a separate Slack window anyway. In that case, a lighter Slack client is likely a better return on effort than a full migration.

Data and compliance needs. If your team handles sensitive data and has retention or audit obligations, a self-hosted option like Mattermost gives you full control. If those requirements do not apply, the operational cost of running your own server probably outweighs the benefit.

Hardware reality. Audit the machines your team actually uses. If the oldest laptop on the team is five or more years old with 8 GB of RAM or less, the official Slack client's memory footprint becomes a genuine daily friction rather than a theoretical concern.

Feature completeness today, not on a roadmap. Every platform has a list of features in progress. Base your decision on what the tool does reliably right now, not on what it promises to do. This applies to msga as much as to any other project.

Making a pragmatic choice

For most small teams the honest answer is: the platform you already use, with the lightest client available for it, is often the path of least disruption. If you are on Slack and want to stay on Slack, msga offers a meaningful reduction in resource usage without asking anyone to change their workspace or habits. If you genuinely need to leave Slack — because of cost, data sovereignty, or vendor lock-in — Mattermost is the most mature open-source alternative with a path to self-hosting that a technically confident team can manage.

There is no single right answer, but there is usually a clearly wrong one: choosing a tool based on its marketing page rather than a short trial on the hardware your team actually owns.

You can download msga from /#download and try it alongside your existing Slack workspace at no cost. The project is open-source, so you can inspect the code, file issues, and contribute improvements on GitHub.