What's been your experience with Slack free tier?


Hi there,

Code for Denver has always used Flowdock since one of our captains works for CA and got us the paid plan for free, which provides unlimited chat history. There’s a strong interest in switching over to Slack, but we were rejected from the free Nonprofit Standard Plan upgrade because of a rule started in 2015 that only allows 1 free upgrade per registered 501c3 nonprofit (and Code for America already has one or potentially several from before that rule). That means we’d be using the free tier, but there’s concern about how the 10k message limit will affect us.

We realize this is an opportunity to be intentional about structured vs. unstructured communication (ie. using Google Drive to store information that needs to exist permanently). I know that thumbnails of pinned messages will always remain (up to ~183 characters) in the Pinned tab, and file attachments will always remain in the Files tab, and that we can create an integration that exports older messages. But we don’t really have a sense of how quickly we’re going to reach that 10k limit, or if it will be disruptive to ongoing conversations, etc.

We have > 500 users in Flowdock, but the number of active users is much smaller, so I’m trying to find out how many messages we actually send per month. In the meantime, I wanted to reach out to see if any other brigades are using the free tier, how many people you have, and what your experience has been. Do you find the limit disruptive?

Thanks so much,


Code for Philly lucked out with a free premium-level nonprofit account that lets us do SSO with our website even…I think it’s way too useful for our own good.

I’m involved in a couple other really active slack communities under the 10k plan though and find it really frustrating in the workspaces busy enough to hit the 10k limit. The worst thing is that it applies to private messages. You’ll log in to pull up one of just a few private messages you exchanged with someone a couple weeks ago, maybe without even having read them yet and there will just be a totally blank screen because there’s some other channels that are noisy.

I’ve been hearing that Mattermost has come a long way since I last checked it out and is a totally viable alternative. If some brigade at the point of starting fresh with a chat system was willing to give it a try I think we could recruit some devops people from around the network to build up some expertise hosting a copy for them and then offer it to many.


Wow, Mattermost looks awesome. David and I are going to try spinning one up for exploration. Thanks so much for your input, I’ll let you know what we find out.


@chris - @dviramontes and I are really impressed with Mattermost and would love to host a copy for development and user testing. It would only cost $5/month on an EC2 spot instance for testing (for production we’d have to switch to a regular instance, more like $15-20/month). We can test this with a small group within Code for Denver, but also wondering if people from other brigades would want to be involved. It’d be great to get input from folks all over the network about their communication needs and what custom features would be useful, if we do have an opportunity to offer it to many.

@tdooner, @chris, how would you recommend going about this?


Is the deployment container based? It might make more sense to provision one VM that could host containers for multiple mattermost instances for different brigades and have a team that admins them all together.


+1 I really like the idea of this being a brigade network infrastructure tool.


That’s a great idea. Would Code for America be paying for the VM?


@eemshi maybe someday, but I wouldn’t predicate the strategy on getting them to commit to that first. If we have a volunteer team doing the devops work and running containers on a shared VM, the hard costs should be pretty minor and something all the brigades using it could cover by pitching in just a few bucks. I think it’s safe to conclude this would be the cheapest and most sustainable route–if we can pull off the devops team and the user experience works for brigade members.

We can get donated server credits to cover a machine at least during a pilot phase. I think I could get a major host to sponsor the work with VM capacity.


Next to Mattermost, I’ve also heard about Riot.

Then there is RocketChat or Discord. The latter also having free SaaS solution as far as I can tell.


I’m looking into setting up Riot or Mattermost to integrate existing channels (dozen of Slacks, Whatsapp, etc.)


@KrzysztofMadejski be sure to check out Matterbridge if you haven’t seen it already, it’s the one thing that makes me think migrating our communities away from Slack (or at least away from depending on Slack) is actually feasible


Hi @chris!
I finally got to work on Matterbridge, one ring to rule them all chats. I managed to set it up on Azure, which is free for nonprofits and I’m linking all Code for All organizations worldwide documenting shared channels here: https://github.com/Code-for-All/matterbridge-config. Let me know if you need support with that.

While doing some research for in-kinds I found out that Mattermost offers non-profit licenses for up to 1000 users: three-years for a one-time fee of 250USD: https://mattermost.com/nonprofit/ (FYI @eemshi)

Altough I’m +1ing the idea of having shared donated infra (Azure and AWS does it already) + shared dev ops to overlook that. That would cut costs a lot!

Final note: if you have devop and admin on your team it might be not that expensive to get bare-metal servers. We host our infra on hetzner.de.