When Slack or self-hosted Zulip fits your team
Slack fits a team that wants a managed product, an established app ecosystem and no server to run, and Zulip fits an asynchronous team that wants topic-based threads and control over where its messages live. Choose Slack when your people work in live, fast-moving channels and depend on Slack's integrations and admin tooling. Choose self-hosted Zulip when a renewal, a pricing change, a residency rule or lock-in pressure makes you want the server, the data and the admin rights inside your own infrastructure, and when your teams are comfortable reading conversations by topic rather than by a flat channel stream.
Three questions decide most of the outcome. The first is history retention. Slack's Free plan keeps 90 days of message and file history, and Slack states that content on Free workspaces older than one year is permanently deleted, so confirm what your current plan keeps and what your legal or records obligations require before you compare costs. The second is who operates the server. Zulip's self-hosting page says the self-hosted server is the same software Zulip Cloud customers use, but someone on your team or a partner must run upgrades, backups and the database, and that work recurs for as long as you run it. The third is whether the app ecosystem is essential. Zulip's help center documents imports from Slack, Mattermost and Rocket.Chat, but Slack apps and workflows will need to be inventoried and rebuilt on any target, so list the ones your teams use before you commit.
Which option fits which scenario
This table maps common Slack situations to the option that fits better and the condition that decides it. Read each row against your own team size, compliance obligations and dependence on Slack apps before choosing.
| Scenario | Better fit | Condition that decides it |
|---|---|---|
| Asynchronous engineering teams that work across time zones | Zulip | Zulip's topic-based threads keep long discussions readable when people catch up hours later; Slack suits teams that mostly chat live in channels. |
| Teams that depend on many Slack apps and workflow automations | Slack, or Zulip after a rebuild | Zulip has its own integrations and bots, so inventory every Slack app and confirm a Zulip equivalent exists before choosing Zulip. |
| Regulated organizations needing SAML or LDAP without a paid tier | Zulip | Zulip's self-hosted server has no open-core limits on SAML, LDAP or SCIM, so these features do not require a paid plan. |
| Self-hosters needing mobile push notifications for more than 10 users | Zulip Basic or Business plan | Community limits mobile push to 10 users for most organizations; confirm current plan terms on Zulip's plans page before budgeting. |
| Small teams hitting Slack Free's 90-day history limit | Zulip Community, if self-hosted | Zulip keeps full history on your own server without deletion at one year, but you must run and back up the server yourself. |
| Teams that need Slack Connect with outside partners | Slack, or Zulip with a federation plan | Zulip has no direct Slack Connect equivalent; confirm how guest access and external sharing will work before migrating partner channels. |
| Organizations that want vendor-supported help for a self-hosted server | Zulip Business plan | The Business plan adds email and chat support for SAML, AD/LDAP sync and data exports, which Community does not include. |
How Zulip topics change daily channel use
For most people in a Zulip organization, the daily change is in how they post and read. In Slack, a channel is a single running feed, and threads hang off individual messages. In Zulip, a stream is a named channel, and every message in it carries a topic, which is a short label for the subject. Readers can scan a stream by topic, follow only the topics they care about, and reply to a topic without interrupting the rest of the stream. Because each topic keeps its own history, someone who was offline for a day can catch up on one subject without reading everything posted in the channel.
- Topic naming: Each message needs a topic, so posters name the subject before they write. Good topic names are short and stable, such as a project milestone or a support case, which makes them easy to find later.
- Reading by topic: Members can open a stream and see its topics in a list with unread counts, instead of one long feed.
- Replies stay in context: A reply goes into the topic it belongs to, so side discussions do not bury the main thread.
- Narrowing searches: Search and filters can target one stream and topic, which helps when reconstructing a decision.
- Relearning habits: Users used to Slack threads may post new messages where they would have replied, so the first weeks need some coaching.
Before rollout, ask a pilot group to post and read for a week and check whether topic names stay consistent and whether people can find old decisions without help.
Team leads usually care about whether the channel records decisions, whether people in other time zones can follow work without a meeting, and whether the team keeps its focus. Topics help here because each one can represent a piece of work that stays open until it is closed. A lead can ask a team to open a topic for each release, incident or customer issue, then read the topic list at the start of a day to see what moved overnight. Decisions made inside a topic remain attached to that subject, which is easier to revisit than a thread buried under later chatter in a Slack channel.
- Work tracked by topic: A topic can stand for one initiative, so status is visible at the stream level without a separate tracker for small items.
- Handoffs across time zones: A lead can point a colleague to a topic and its full history instead of summarizing it in a call.
- Fewer parallel side threads: Conversations about one subject stay together, which reduces the duplicate questions that appear when threads fragment.
- Norms to set: Leads decide how topics are named, when to rename or resolve them, and which streams are public to the organization.
- Limits of topics: Topics help structure work but do not replace a task tracker, so teams with formal workflows will still need one.
Ask the team which recurring work should become a stream and which should stay a topic, and document that choice before the first week of use.
Admins own the account, stream and permission model, and they carry the cost of getting it wrong. Zulip's self-hosted server includes the same features Zulip Cloud uses, including SAML, LDAP and custom roles, so the design work is about who can create streams, who can see them and how identity flows from the directory. Slack channels have a similar purpose, but Zulip streams have their own permissions and invitations, so admins should map existing Slack channels to streams with intention rather than copying the structure as is. Migration and onboarding also depend on the export plan the Slack workspace used.
- Stream permissions: Decide which streams are public to all members, which are invite-only and who can create new streams.
- Identity integration: Confirm how SAML or LDAP provisioning maps users and groups to roles before inviting the team.
- Stream mapping: Plan which Slack channels become streams and which become topics, since the mapping shapes how history reads after import.
- Retention and exports: Set the data retention and export policy in the server configuration so the team knows what persists.
- Adoption support: Publish posting norms and assign owners to watch topic naming during the first month.
Before cutover, confirm with Zulip's documentation for your server version which import and identity settings apply, and test them on a copy of the organization.
Capabilities side by side
This table compares Slack and self-hosted Zulip across licensing, identity, threading, import, mobile notifications and support. Items marked as facts to confirm depend on Slack's current plan terms or Zulip's current documentation, so check them before a renewal decision. The main takeaway is that Zulip's identity features are available on the self-hosted server without a paid plan, while Slack's export and retention rights depend on the plan you hold.
| Capability | Slack | Zulip (self-hosted) |
|---|---|---|
| License | Proprietary SaaS, no self-hosted option | Apache License 2.0 |
| Self-hosting | Not available; runs only in Slack's cloud | Self-hosted on Ubuntu or Debian, in Docker, or on prebuilt DigitalOcean and Render images |
| SAML and SSO | Available on paid plans; confirm which tier includes SSO for your organization | SAML with IdP-initiated SSO and Single Logout, no paid plan needed; Keycloak and Authentik guides exist |
| LDAP and Active Directory sync | Confirm current directory sync options with Slack's documentation | LDAP including Active Directory with data synchronization, included in the self-hosted server |
| SCIM provisioning | Confirm current SCIM support and the plan that includes it | SCIM documented in Zulip's production documentation |
| Topic-based threading | Channels with threaded replies under messages | Every message has a topic inside a stream, designed for live and asynchronous conversation |
| Slack import | Not applicable; the source of the export | Imports Slack exports into streams and topics; confirm which message types and files carry over |
| Mobile push notifications | Included on all Slack plans | Free self-hosted Community plan limits mobile push to 10 users for most organizations; Basic plan at $3.50 per user per month billed monthly, per Zulip's plans page |
| App ecosystem | Large marketplace of apps and bots; confirm which apps you depend on in Slack's current directory | Integrations and bots exist, but Slack apps do not run unchanged; inventory and rebuild each one |
| Admin and vendor support | Vendor-managed cloud with plan-based support; confirm your tier | You run the server; paid support on Business plan with email and chat support, per Zulip's plans page |
Where your messages live and who controls them
Slack keeps your messages in its cloud under its retention rules and export tiers. A self-hosted Zulip server puts the messages, the identity links and the export decisions inside your own infrastructure, which also makes you responsible for running and evidencing them. The cards below cover each of those decisions in turn.
Where message data sits
In Slack, messages, files and member data live in Slack's cloud, so your residency position depends on the plan and the region terms you hold. With self-hosted Zulip, the database, uploaded files and backups sit on servers you choose, whether in your own data center or a provider account you control. Ask your team to map every location where message content, uploads and backups are stored, including any object storage and log sinks, before you compare it with Slack's terms.
Hosting models to choose from
Zulip can be installed directly on Ubuntu or Debian Linux, run in Docker through the docker-zulip project, or launched from prebuilt images for DigitalOcean and Render. Direct installs give the operator the most control over the host, while containers simplify rebuilds but add a layer to patch. Pick the model with your platform team before you size storage and backups, because the choice changes who applies operating system and runtime updates.
Identity through your own IdP
Zulip's self-hosted server supports SAML, LDAP with Active Directory synchronization and SCIM without a paid plan, so sign-in can run through your own identity provider. Zulip's documentation includes setup guides for Keycloak and Authentik as SAML identity providers. Confirm which IdP holds the authoritative user list, how deprovisioning reaches Zulip, and who owns the SAML certificates and their renewal dates.
Export and retention ownership
On Slack, the export tier decides what you can take out, since private channels and direct messages need Business+ or Enterprise and custom exports are Enterprise-only. Zulip's self-hosted server is yours to back up and query, and its help center documents importing data from Slack, Mattermost and Rocket.Chat. Decide who sets retention and legal hold on the server, and test a restore before you rely on it as the record.
Compliance evidence and auditors
DeployOpen prepares the configuration, access records, backup evidence and runbooks that a compliance assessment will ask for, mapped to the controls your framework requires. DeployOpen does not issue audit reports, attestations or certifications, and independent auditors or certification bodies decide whether your controls meet a standard. Ask your assessor early which evidence they will accept from a self-hosted chat server, since Slack's vendor attestations do not transfer to your own system.
Support and patching responsibility
Slack operates the service, its security patches and its uptime, so your team mainly manages users and settings. A self-hosted Zulip server moves operating system patching, Zulip upgrades, database maintenance and incident response to your staff or to a support partner. Zulip's paid Business plan includes email and chat support for SAML and AD/LDAP sync, and the release cadence is visible on the releases page, for example Zulip Server 12.3 published on September 21, 2026. Write down who receives release notices and who approves each upgrade.
What Slack's export plan decides before you move
Your Slack plan decides how much of your history can leave Slack at all, so confirm it before you choose a target. Every Slack plan can export messages and file links from public channels. Exporting private channels and direct messages requires Business+ or Enterprise, and custom exports by member or conversation are limited to Enterprise. If your workspace is on Free or Pro, plan on the public channel history being the only complete set you can take out through the standard export, and treat private channels and DMs as data you may never receive. Check the current export options with your workspace owner and the Slack help center article on exporting workspace data before you start.
Those export limits flow straight into what Zulip's importer can bring across. Zulip documents a Slack import path, and the completeness of that import depends on what Slack hands it. Ask which channels, private groups and direct messages are present in the export file, and map them to Zulip streams and topics on paper before the first test run. Confirm that the export contains the users and file attachments you need, because a partial export leaves gaps that are hard to fill after cutover, when Slack may already be closed to members. Run the import against a copy in a staging Zulip server first, and compare message counts per channel with the source.
Time also matters. Slack's Free plan shows 90 days of message and file history, and Slack states that content on Free workspaces older than one year is permanently deleted. A small team on Free may therefore lose older history with no way to recover it from Slack. Teams in that position should request the export now rather than after a renewal or a plan change, and should record which plan the workspace is on today. Waiting for the next billing cycle can turn a routine migration into a data recovery exercise.
What Slack and self-hosted Zulip cost to run
Slack bills per seat and per plan tier, while self-hosted Zulip moves the bill to servers, storage, administration and optional paid support. The cards below separate what is one-time from what recurs, so a quote can be compared line by line with your current Slack invoice.
Slack seats and plan tier
On the Slack side, the recurring cost is the number of paid seats multiplied by the plan tier you need. Export access is the tier question: private channels and direct messages need Business+ or Enterprise, and custom exports by member or conversation are Enterprise-only. Check which tier your compliance team actually needs before comparing totals, because a lower tier may not allow the export you plan to take on exit.
Server hosting, storage and backups
Self-hosting Zulip replaces seat fees with infrastructure you pay for directly: compute, database and cache capacity, object or disk storage for uploads, and backups kept off the primary host. Costs rise with message volume, file attachments, retention length and the number of backup copies you keep. Ask your cloud or data center team to price a production sizing and a tested restore, not just a single server.
Free Community plan push limit
Zulip's free self-hosted Community plan includes all features, but mobile push notifications are limited to 10 users for most organizations. Teams above that size either accept no push alerts on phones or move to a paid per-user plan for notifications. Confirm your headcount and how many staff rely on mobile alerts before deciding that the free plan covers your needs.
Basic and Business per-user prices
Zulip's published per-user prices are the reference point for paid self-hosted support. Basic costs 3.50 dollars per user per month billed monthly and includes unlimited mobile notifications. Business costs 6.67 dollars per user per month billed annually or 8 dollars billed monthly, with a 25-user minimum, and adds email and chat support for SAML, AD/LDAP sync and data exports. Enterprise pricing is custom, so request it in writing if you need it.
DeployOpen fixed-scope setup
DeployOpen plans, implements, integrates, hardens and documents a self-hosted Zulip deployment, usually as a one-time fixed-scope engagement agreed in writing before work starts. Ongoing support, upgrades and testing are separate retainers. DeployOpen does not publish a price list, so the quote follows from the written scope, which should list the Slack import, identity integration, backup testing and handover documentation as separate deliverables.
Administrator time and upgrades
Administrator time is the cost most often left out of comparisons. Someone must run upgrades, watch the Zulip release cadence, maintain LDAP or SAML integration, manage user lifecycle and handle incidents. Ask for a monthly administration estimate from your own platform team, and include who covers on-call and how upgrades are tested before they reach production.
How a move from Slack to Zulip runs
The sequence confirms what your Slack plan can export, moves history into a self-hosted Zulip server, and retires Slack only after users, identity and notifications work on the new system. Each step ends with a check you can verify before the next one starts.
Confirm export plan and inventory the workspace
Your team confirms which Slack plan you are on and what that plan allows you to export. Public channels can be exported on every plan, while private channels and direct messages need Business+ or Enterprise, and custom exports by member or conversation are Enterprise-only, according to Slack's export documentation. In the same step, list channels, members, admins, guests, integrations, bots and custom emoji so you know what must be rebuilt. The output is a signed-off inventory that states which conversations are missing from the export, if any.
Export workspace data from Slack
A Slack workspace owner or admin with export rights runs the export from Slack's administration settings and downloads the archive. Check that the archive contains the channels and date range you agreed to, and record any private conversations that the plan did not cover. The output is a stored, access-controlled archive kept in your own storage, with a note of the gaps that the export cannot fill.
Run the Zulip Slack import on a test server
Your platform team installs Zulip on infrastructure you control, using the self-hosting route that fits your environment, and runs the Slack importer from Zulip's import documentation against the archive on a non-production instance. Review the import log for skipped files or users. The output is a test realm that loads without errors and whose user and message counts match the inventory.
Map Slack channels to Zulip streams and topics
Decide which Slack channels become Zulip streams, which become topics inside a single stream, and who can see each stream. Zulip's topic model changes how conversations are grouped, so review busy channels with the teams that use them. Agree the naming rules and the stream permissions with channel owners. The output is a signed mapping document that channel owners approve.
Configure SAML or LDAP and SCIM provisioning
Your identity team connects Zulip to your identity provider using SAML, or LDAP and Active Directory synchronization, and sets up SCIM provisioning where your environment requires it. Zulip's production documentation covers these options, and guides exist for Keycloak and Authentik as SAML identity providers. Test sign-in, single logout and the removal of a test user. The output is a test login path that deprovisions accounts as expected.
Test mobile push notifications and plan the paid tier
Test push notifications on the mobile apps for a pilot group. Zulip's free self-hosted Community plan limits mobile push notifications to 10 users for most organizations, so confirm the user count and whether the Basic plan's unlimited notifications are needed, using Zulip's plans page for current terms. Ask Zulip for a written quote for the paid tier if required. The output is a documented notification decision and a confirmed pilot result.
Run both systems side by side and cut over
Keep Slack available in read-only mode for your agreed overlap period while pilot teams work in Zulip, and rebuild integrations and bots on Zulip as a separate workstream, since they are not carried over by the import. Announce the cutover date, move remaining teams, and point links, bookmarks and onboarding materials to Zulip. The output is a cutover record showing that new conversations happen only in Zulip.
Retire Slack access and archive what remains
Once the cutover record is signed, remove Slack user access, cancel the Slack plan at the point your contract allows, and keep the export archive under your retention policy. Confirm with your compliance lead which records must be kept and for how long. The output is a closed Slack workspace, a retained archive and a handover document that lists what your team owns going forward.
Questions buyers ask before choosing Zulip
What does a self-hosted Zulip deployment cost compared with Slack plans?
Zulip's server software is free to download and run, so the cost is the infrastructure, the administrator time and any paid support you choose. The Zulip plans page lists Basic at $3.50 per user per month billed monthly and Business at $6.67 per user per month billed annually or $8 billed monthly with a 25-user minimum, while Enterprise pricing is custom. Those are Zulip's subscription prices for support and mobile notifications, not for the software itself. Compare them with your Slack per-seat bill, then add the servers, backups, storage, email delivery and the staff hours to patch and upgrade. Ask Zulip or your partner to quote the support tier that matches your user count, and treat the free Community plan as the baseline, not the total.
How long does a Slack to Zulip migration take?
The duration depends on the size of the export, how many channels and users you bring across, whether you need private channels and direct messages, and how much cutover planning your teams need. Zulip's help center documents an import path from Slack, but the time it takes in your environment is not a figure this page can give you. The Slack export plan matters most, because private channels and direct messages only come out of Slack on Business+ or Enterprise. Ask for a written scope that lists the workspaces, channels, history period, integrations and cutover approach before agreeing on any timeline. A fixed-scope engagement with written deliverables is the usual way to pin that down.
Can an internal team run Zulip without a partner?
Yes, many teams run Zulip with in-house staff, provided they have Linux administration skills and someone accountable for upgrades. Zulip can be installed directly on Ubuntu or Debian, in Docker through docker-zulip, or on prebuilt images, and the server is the same software Zulip Cloud customers use. Zulip Server 12.3 was published on September 21, 2026, so plan for regular upgrades and check the release notes before each one. The harder parts are usually identity integration, email and mobile push configuration, backups, and the import itself. Decide early which of those your team will own, and whether a retainer for upgrades and testing fits your staffing model.
What does Zulip need from our identity and infrastructure teams?
Identity and infrastructure teams usually own most of the critical setup. Zulip's production documentation covers LDAP, including Active Directory with data synchronization, SAML with IdP-initiated SSO and Single Logout, and SCIM, with guides for Keycloak and Authentik as SAML identity providers. Your identity team needs to decide the authoritative directory, which groups map to Zulip roles, and how deprovisioning happens when someone leaves. Infrastructure teams should plan hosting, TLS certificates, DNS, outbound email for account and notification traffic, storage, backups and network access for mobile clients. Confirm each item against the production requirements page before scoping, because the exact configuration depends on your directory and your network.
Do Slack integrations carry over to Zulip?
Assume that most Slack integrations and bots will need to be rebuilt rather than copied across. Zulip's help center documents importing data from Slack, and the import brings over the messages and conversation history it supports. Apps, slash commands, incoming webhooks and bots live outside the export, so each one needs an owner, a target Zulip integration or webhook, and a test before cutover. Build an inventory of every app connected to Slack, then sort them into those you still need, those Zulip already covers and those you can retire. Ask the import documentation for the exact mapping of channels to streams and topics before you agree which history goes across.
Do mobile push notifications need a paid plan above 10 users?
For most organizations, yes. Zulip's free self-hosted Community plan includes all features but limits mobile push notifications to 10 users. Unlimited mobile notifications require a paid plan, with Basic at $3.50 per user per month billed monthly according to the Zulip plans page. The Business plan also covers email and chat support for SAML, AD/LDAP sync and data exports. Before you commit, count the users who will need push on their phones, not the total headcount, and confirm with Zulip how the limit applies to your deployment. Teams that only need desktop or web notifications may have a different cost picture.
When staying on Slack is the sounder choice
Staying on Slack is the better choice when your value depends on things a self-hosted Zulip server does not give you by default. The most common case is Slack Connect. If your work runs through shared channels with customers, vendors or partners who already sit in Slack, moving to a separate Zulip server means those external people must join your server or you must rebuild the shared space, and that negotiation falls on you. The same applies to a large catalog of Slack apps, bots and workflows that your business relies on daily. Zulip's integrations and API are capable, but every app you rely on has to be confirmed, reconfigured or replaced, and the Slack import does not carry integrations across. Before deciding, list the external workspaces you share channels with and the apps that post into critical channels, and check each one against Zulip's supported integrations in the Zulip documentation.
Staying on Slack also makes sense when you want someone else to run the service. Slack is a managed cloud product, so patching, backups, uptime and scaling are the vendor's responsibility. With Zulip, the switching effort is front-loaded: you plan the server, configure SSO through SAML or LDAP, run the import, retrain users on topics and cut over. After that, operating the server is a recurring job covering OS and Zulip upgrades, database and file backups, certificates, monitoring and on-call response. Zulip ships new server releases regularly, so ask whether your team can keep pace with them, or whether a retainer for upgrades and support fits better. If you have no one to own that work, the total cost of a self-hosted server can exceed the Slack plan it replaces, even when the license is free.
How DeployOpen helps evaluate and move your team to Zulip
DeployOpen plans, implements, integrates, hardens, backs up, documents and supports self-hosted open-source platforms inside your own infrastructure. For Slack vs Zulip, we start with a written scope that tests how your teams actually use channels, topics and private conversations before any server is built.
How we scope
- Inventory which Slack channels, private conversations and apps your teams depend on today
- Confirm which Slack export plan you hold and what that export can actually include
- Agree the hosting target, identity provider and user count in a written, fixed scope
How we build
- Deploy Zulip on your chosen infrastructure, whether direct on Linux, in Docker or on your cloud
- Configure SAML, LDAP or SCIM against your identity provider and test sign-in before rollout
- Import the Slack export, map channels to streams and topics, and verify the results
How we hand over
- Document the server build, upgrade path, backup and restore steps for your own administrators
- Provide a test report covering imported history, permissions, notifications and integrations
- Run a handover session so your team can operate Zulip without outside help
How we support
- Offer ongoing support, upgrades and continuous testing as a retainer after handover
- Track new Zulip releases and plan upgrades in a scheduled, tested change window
- Ask any quote to itemize setup, migration, hosting, support and staff time separately
