Slack revolutionized workplace communication when it launched. It offered all solutions faced in a modern platform for messaging, file sharing, and collaboration. But Slack’s pricing has become increasingly expensive as teams grow, with per-user costs that can quickly balloon to thousands of dollars for organizations. Companies have started looking for some other best open source Slack alternatives that give the same features without spending so much money. If you’re one of them, this guide can be your lifesaver!
Best Open Source Slack Alternatives
From low-cost to free platforms, here are some of the top alternatives to look out for.
1. Chanty
Chanty is perfect if your team loves keeping things simple and task-focused. This platform puts teamwork front and center. How? By blending messaging with task management. Its AI interface highlights all the tasks, while a teambook keeps messages, files, and activities in one place. It also supports private and group chats, voice and video calls, and hooks up with popular third-party apps to keep your workflow moving.
Pricing: Includes free membership and a $3/month business plan.
2. Microsoft Teams
We have all heard about Microsoft Teams. It is fit if your team relies on Microsoft’s suite of tools, deeply integrating chat, file sharing, and video conferencing. Group chat supports threaded conversations and edits. You can also easily schedule calls or tasks to keep your projects on track. Moreover, Teams plays well with OneDrive and all Office apps, making collaboration unified for those businesses already in Microsoft’s ecosystem.
Pricing: The pricing includes a free plan, then Microsoft Teams Essentials at $4.00/month, and Microsoft 365 Business Basic at $6.00/month, with the highest tier being Microsoft 365 Business Standard at $12.50/month.
3. Discord
Though originally for gamers, Discord is catching on with businesses looking for a free, chat platform. It offers text messaging, voice chat with push-to-talk, live streaming, and screen sharing. Unlimited message history and generous storage, even on free plans it a solid Slack alternative for teams wanting rich collaboration without breaking the bank.
Pricing: Discord’s premium subscription plans are Nitro at $9.99/month (or $99.99/year) and Nitro Basic at $2.99/month (or $29.99/year)
4. Pumble
What’s unique with Pumble is its unlimited users, messages, and history, even on its free plan, compared to the competition. It takes up the best parts of email, MS Teams, and Slack to give teams a powerful toolset that feels comfortingly familiar. You get direct messaging, channels, threaded conversations, file sharing, and voice and video calls. Paid plans unlock the ability for screen sharing and admin tools to round out the experience for growing teams.
Pricing: There is a free plan available, Pro is at $2.49/month, Business administration at $3.99/month, and Enterprise at $6.99/month.
5. Flowdock
Flowdock started as a dev tool but evolved for project managers to needed more focus on collaboration. Conversations are color-coded threads, which help keep discussions neat even in busy teams. You also get screen sharing, video calls, and a shared inbox for team queries or client messages. An open API lets you hook in as many apps as you want, and that’s why it ranks as one of the best open source Slack alternatives.
Pricing: 30-day free trial; $3 per user per month.
6. Google Meet
Another popular mention in this list is Google Meet. It works best when your team lives in Google Workspace. It’s a video-first platform with chat, file sharing, and direct messaging built in. The best part is that it is all wrapped with Google’s security features. You can set up meetings with call recording, breakout rooms, and screen sharing. The app also supports direct text chats and integrates with tools like HubSpot and Salesforce for business-friendly workflows.
Pricing: Free, $6 per user per month
7. Zulip
Zulip brings a neat twist to group chat by mixing real-time messages with an email-style thread structure. This makes it easy to keep every conversation on track! Teams can hash things out, joke around with emojis, and even share code or math equations, all while never missing a beat. All these plus points make it one of the best open source Slack alternatives.
Pricing: Free plan. Standard plan at $6.67 per month and Plus plan at $12 per month.
8. Let’s Chat
Let’s Chat is perfect for smaller teams who want a fuss-free, self-hosted chat app that just works. You get full control over where your data lives. It offers lots of privacy thanks to private rooms and a simple layout that helps everyone stay in the loop without distractions.
Pricing: Free plan.
9. Rocket.Chat
Rocket.Chat is a go-to choice for teams looking for fast but also secure messaging. Instead of slow emails, you can turn group conversations into instant messages, private channels, and searchable threads. Customizing is easy since the source code is open, and admins have control to tweak settings as needed. Plus, security is beefed up with features like end-to-end encryption and two-factor authentication.
Pricing: Fully free version with limited users. Pro package starts at $4 /user/month when paid annually.
10. Mattermost
Mattermost is all about flexible messaging for teams that are looking for control. Its impressive features marks the first as one of the best open source Slack alternatives. You can run it on your own hardware, select your cloud provider, or even make permissions. Its DevOps integrations keep workflows tight, and custom options allow you to build whatever fits your crew right.
Pricing: Professional plan at $10 /user /month if billed annually. Request a quote for the Enterprise and Enterprise Advanced plans.
11. Nextcloud
Nextcloud pulls together everything you need for digital teamwork. Email, video calls, and shared files stay private with full encryption and on-premises hosting. Whether you want to run Nextcloud on a Raspberry Pi or go with a hosting provider, it works well for both newbies and pros, and comes packed with integrations to make daily work smoother.
Pricing: For Enterprise support, Nextcloud offers four premium plans, starting at 100 users and 37.49€/user/year.
16. Twake
Twake is designed as a digital workspace that brings together everything a team needs. So you get chat, file sharing, project management, video calls, and document collaboration all in one platform! Whether you’re organizing discussions or setting tasks, Twake makes teamwork easy. Security gets a strong emphasis with encrypted storage and strict permission controls, so you never have to stress about privacy or compliance. Its tool integrations and real-time collaboration keep everyone connected and productive, and best open source Slack alternatives.
Pricing: Free, Standard at €4.19/month, Premium at €10.39/month if billed yearly, and Enterprise can be customized.
17. Matrix
Matrix shakes up the world of online chatting by offering an open, decentralized system for instant messaging and calls. No central authority, just pure flexibility across devices and apps! Built with security at the heart, Matrix supports end-to-end encryption for both direct and group messaging. Developers love it because they get to build bots or custom solutions, and everyday users can join public or private chat rooms with just a click. Its bridges and APIs help link communication without worrying about vendor lock-in.
Pricing: Free
18. Element
Element is another best open source Slack alternatives, which is all about secure communication built on the open Matrix standard. With its decentralized approach, each organization or user can choose where and how to host their chat app. Element combines instant messaging, video, and voice calls, and even bridges to other apps, making it versatile for teams of any size. The platform’s admin tools help tailor rooms, manage access, and set permissions, making it one of our best open source Slack alternatives.
Pricing: Free Starter pack. Paid packages range between $5-$10 when paid annually.
19. Wire
Wire is a privacy-focused chat and collaboration platform trusted by big organizations worldwide. With end-to-end encryption, it’s built for companies and public institutions where data protection is a must-have. Wire runs on a federated framework, so different teams or branches can have their own spaces while maintaining tight control over shared information. The platform’s cross-device compatibility and support for large video conferences also make it ideal for everyday messaging.
Pricing: Free plan. Wire for SMB plan at an annual payment of €8,94 per person/month.
20. Tox
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Pricing: Free
21. Jitsi Meet
Jitsi Meet is all about bringing teams together with secure video calls. The best part is, you can use it without any sign-up. You get encrypted group meetings, screen sharing, and recordings. It even works right out of your browser or apps, making it one of the best open source Slack alternatives. Though it’s video-centric, Jitsi can be paired with other messaging platforms to round out your team’s remote toolkit and can be hosted privately or used in the cloud.
Pricing: Free
22. IRC (Internet Relay Chat)
IRC is the original text-based chat platform that’s still alive and kicking. It lets you connect to servers worldwide, join chat rooms, and jump into conversations on just about any topic. While it feels old-school compared to modern apps, its simplicity means you don’t have to mess with profiles. Just pick a nickname and start chatting straight away. It’s perfect for casual chatting or big hobby groups, giving users anonymity and open access.
Pricing: Free
23. Corteza Messaging
Corteza Messaging gives teams control over their chats with a flexible, open-source platform that you can self-host. It’s great for organizations wanting privacy and a clean, organized messaging experience. You get both private and public channels, threaded conversations, and options like push notifications and custom statuses. It also supports file sharing and emojis, making conversations lively and easy to follow.
Pricing: Free
Also Read: 10+ Best AI Tools for Telegram to Save time
Now you will no longer have a difficult time figuring out the best open source Slack alternatives after following this guide. For more helpful tips and tricks, stay tuned, and feel free to share your suggestions in the comments below.
