Which open-source chat replaces Zoom Team Chat on your own servers
If a Zoom renewal, licensing change or data residency rule has made the bundled persistent chat a separate decision, the main self-hosted options are Mattermost, Rocket.Chat and Matrix with Element. Each can be linked to a self-hosted Jitsi Meet or BigBlueButton server so that conversations and meetings stay on infrastructure you control. Chat and meetings are separate components, so this is a two-part project rather than a single swap: you choose a chat platform, then decide how its calls and meeting links reach your meeting server. Meeting replacement itself is covered on the Zoom Jitsi and BigBlueButton pages, so this section concentrates on the chat decision.
The first check is identity. Mattermost gates SSO (SAML, OIDC, OAuth) and AD/LDAP user sync behind its Professional plan and above, while Rocket.Chat's free Starter plan includes LDAP, Active Directory and single sign-on for up to 50 users. Synapse supports OpenID Connect, SAML2 and CAS. Confirm which of these your directory and sign-in policy require before you compare prices. The second check is scale and high availability: Mattermost high availability is limited to its Enterprise and Enterprise Advanced plans and needs shared file storage on each node, and Rocket.Chat's multi-instance and microservice designs require a paid plan. Ask each vendor for the exact plan that covers your user count and availability target.
Your total cost is the chat software or subscription, plus the servers, database, storage and backups, plus the staff time to upgrade and operate the platform. Upgrade cadence is the recurring cost most often underestimated. Rocket.Chat's standard releases are supported for 6 months and LTS releases for 12 months, and Synapse drops support for Python and PostgreSQL versions once they reach upstream end of life. Mattermost publishes a server release on the 16th of each month, with Extended Support Releases such as v11.7 for longer windows. Before you decide, plan a migration test using your own Slack or other chat export, and ask DeployOpen or any implementer for a written scope covering identity, linking to your meeting server, backups and upgrades.
How Zoom Team Chat capabilities map to open-source options
This table compares the persistent chat capabilities of Zoom Team Chat with Mattermost, Rocket.Chat and Matrix with Element. Read each row for the free tier limits and the points where you must confirm support in the version you plan to run before committing.
| Capability | Mattermost | Rocket.Chat | Matrix with Element |
|---|---|---|---|
| Persistent channels and direct messages | Core channels and direct messages are part of the open server. Confirm the feature set of your chosen edition in the editions documentation. | Core messaging is in the free Community workspace, which allows up to 100 concurrent users. Confirm the limit against your edition. | Rooms and direct messages are core to Synapse. Element clients provide the user interface. Confirm room features against your client version. |
| File sharing | Included in the server. Storage location must be shared (S3-compatible or NAS) when running high availability. | Included in core messaging. Plan storage and retention for uploaded files on your own servers. | Supported through the homeserver media store. Plan media storage and retention on your own servers. |
| Search | Included in the server. Search replicas are available for scaling reads on high availability clusters. | Included in core messaging. Large deployments should confirm search performance against their reference architecture. | Message search depends on the homeserver database. Confirm search behavior and limits for your Synapse version. |
| Guest and external access | Guest access is a configurable feature. Confirm how guest accounts are licensed in your edition. | Guest access is configurable. Confirm user counts against the Starter cap of 50 users. | Federation links servers across organizations. Restrict it with federation_domain_whitelist if you need closed access. |
| SSO and directory sync | SSO (SAML, OIDC, OAuth) and AD/LDAP user sync are included from the Professional plan per the pricing page. | LDAP and Active Directory authentication and SSO are on the free Starter plan. Group mapping for LDAP and SAML is listed on paid plans. | Synapse supports OpenID Connect, SAML2 and CAS. Directory sync needs confirmation for your identity provider. |
| Admin and retention controls | Retention and compliance features depend on edition. Confirm which controls your plan includes before migration. | Retention is on Starter. Tamper-evident audit trails are listed on paid plans. | Retention and admin tooling vary by homeserver setup. Confirm the controls you need in the Synapse configuration manual. |
| Mobile and desktop clients | Official mobile and desktop clients are available. Confirm client versions match your server release. | Official mobile and desktop clients depend on a supported server version. Unsupported versions can lose client connectivity. | Element provides mobile and desktop clients. Confirm feature parity with your Zoom app needs. |
| Bots and integrations | Integration support is part of the platform. Confirm plugin and webhook availability for your edition. | Marketplace and Omnichannel integrations stop working after a version reaches end of life. | Bridges connect to other chat networks. Each bridge is a separate component to install and maintain. |
| In-chat calls | Calls in the free Entry tier are limited to 40 minutes. Longer calls need a paid plan or a self-hosted Jitsi link. | Calls are not part of the chat core. Link to a self-hosted Jitsi or BigBlueButton room. Confirm integration steps. | Element Call provides voice and video inside Matrix and is included in Element Server Suite Community. Confirm capacity. |
Which self-hosted chat fits which organization
Each option below replaces the persistent chat that comes with Zoom Workplace in a different way, with different operating models and licenses. All three can sit beside a self-hosted Jitsi Meet or BigBlueButton server, so chat and meetings can run inside the same network boundary. The right choice depends on your licensing rules, your database skills and how many users you expect to support.
Mattermost for a single-binary team
Mattermost runs as a single Linux binary with PostgreSQL as its database, which keeps the first deployment small and easy to reason about. Its compiled binaries are MIT licensed, but high availability with redundant application servers, database servers and load balancers is available only on the Enterprise and Enterprise Advanced plans. Before you commit, confirm which features you need for your user count, and plan shared file storage on S3, an S3-compatible service or NAS for any cluster, since local storage will not work across nodes. Also note that the free Mattermost Entry tier limits calls to 40 minutes, so check that against your meeting habits.
Rocket.Chat for MongoDB operators
Rocket.Chat keeps its core under the MIT license, but the apps/meteor/ee and ee directories fall under a separate enterprise license, so review that boundary with your legal team. Version 8.x requires MongoDB 8.0 or later running as a replica set, and a three-member replica set is strongly recommended for high availability. Reference architectures move from one instance up to 500 concurrent users, to load-balanced instances above that, and to Kubernetes above 5,000 users, but the multi-instance and microservice designs need a paid plan. Plan upgrades carefully, because unsupported versions can lose connections to the official mobile and desktop clients.
Matrix with Synapse and Element
Matrix is a federated protocol, so Synapse can talk to other homeservers on port 8448 or through delegation on port 443, and federation can be restricted with the federation_domain_whitelist setting. Synapse is AGPL-3.0 licensed, and Element's Server Suite Community includes Element Call for voice and video alongside it. Synapse 1.143.0 and later require PostgreSQL 14 or newer, and rolling back is difficult because schema changes between releases can be hard to undo. Confirm whether you need federation at all, since disabling it is a single configuration choice and changes your threat model.
How the chat links to Jitsi or BigBlueButton without leaving Zoom
In a Jitsi setup, the chat is a separate system that only needs a meeting URL to post. Your team decides how the room link appears in chat: a bot, a slash command, or a staff member pasting it into a channel. Before you commit to a chat product, confirm whether it has a native Jitsi integration or needs a plugin or incoming webhook, and who maintains that component after upgrades.
- HTTPS first: Jitsi's self-hosting guide states that HTTPS is necessary for multimedia to work, so the Jitsi host needs a valid certificate before any chat link is tested.
- Room naming: Choose a predictable room naming pattern for channels or teams so links are easy to recognize and do not collide with other meetings.
- Identity: Chat accounts and Jitsi display names are separate. Confirm which authentication options your Jitsi version supports and how the chat user name maps to the name shown in the room.
- Guest access: Test that a link posted in chat opens a room for an external participant without a Zoom account or a chat login.
- Upgrade path: Confirm that the chat plugin or webhook is tested against each Jitsi and chat release, since a mismatch can break link posting.
Check the full path from a chat message to a connected browser on a network outside your office, because certificate and firewall problems often appear only there.
BigBlueButton meetings are created through its API, and room management for most organizations happens in Greenlight, which is BigBlueButton's room manager front end. Chat does not create rooms on its own. The usual pattern is that each user has a persistent Greenlight room, and the chat either carries that room link or calls the BigBlueButton API through a bot. Plan room management and chat accounts as two separate administrative areas.
- Greenlight rooms: Each user or group gets a persistent room link that staff can share in chat channels or direct messages.
- Separate accounts: Greenlight accounts and chat accounts are managed in different systems. Confirm in the BigBlueButton documentation which authentication options your version supports, and whether they can be aligned with your identity provider.
- Server requirements: BigBlueButton 4.0 needs at least 16 GB of memory, 8 CPU cores, 500 GB of disk for recordings, UDP ports 16384 to 32768 and 250 Mbit/s symmetrical bandwidth. Links posted in chat send more participants to the same server.
- Network access: Confirm that the UDP range is reachable from the networks where guests will join before you publish links widely.
- Recording retention: Rooms shared in chat can generate recordings, so set retention and storage limits before rollout.
Confirm whether your chat product needs a bot or webhook to call the BigBlueButton API, or whether staff will paste Greenlight links manually, since that choice determines who supports the integration.
Matrix with Element is the option in this set where chat and voice and video can share one stack. Element Call provides voice and video for Matrix rooms and is included in Element Server Suite Community alongside Synapse, so a room conversation can move into a call without a separate meeting server. Jitsi Meet or BigBlueButton remain useful for classes, webinars or larger structured meetings, so decide where each one fits.
- Single stack: Synapse hosts the messages and Element Call handles calls, which reduces the number of systems that have to be linked and monitored.
- Shared identity: Synapse supports single sign-on through OpenID Connect providers, SAML2 and CAS, so one identity provider can sign users into chat and calls.
- Federation control: The
federation_domain_whitelistsetting restricts federation to listed domains, and an empty list disables it. The documentation also recommends firewalling the federation listener. - Licensing: Synapse is distributed under AGPL-3.0, and Element Server Suite Community is the packaging to confirm with Element, including current terms for calls and support.
- Meeting size: Confirm that Element Call meets your participant counts and quality targets in a test before you retire an existing meeting server.
Verify that single sign-on, call quality and federation settings all work from the networks your users actually use before you announce the change.
What running a self-hosted chat server takes after go-live
The recurring cost of a self-hosted chat server is mostly staff time and the infrastructure underneath it, not a license fee. Start by listing the components each candidate needs and who owns each one. For Mattermost, that is the application server and its PostgreSQL database. A high availability cluster adds redundant application servers, redundant database servers and redundant load balancers, and it requires shared file storage on Amazon S3, an S3-compatible service or a NAS mounted on every node, because local file storage will not work correctly and risks corrupting files. High availability is also limited to the Enterprise and Enterprise Advanced plans, so ask Mattermost whether your chosen tier includes it before you size the cluster. For Rocket.Chat, the database is MongoDB 8.0 or later running as a replica set, with three members strongly recommended for high availability. Each of these is a one-time build cost followed by a recurring cost for compute, storage, backups and the people who patch them.
Synapse adds its own dependencies. Recent releases require PostgreSQL 14 or newer and Python 3.10 or newer, and a deployment that uses workers also needs Redis to relay replication between processes. Confirm the exact minimums against the current Synapse upgrade notes before you choose operating system packages, because Synapse drops support for Python and PostgreSQL versions once they reach upstream end of life. Also ask whether your organization needs database read replicas or search replicas, since each one is another server to run and monitor. The largest recurring cost is upgrade work. Mattermost publishes a new server version in binary form on the 16th of each month, so someone must test and apply monthly releases or choose the Extended Support Release track and plan around its support dates. Rocket.Chat standard releases are supported for 6 months and LTS releases for 12 months, and after end of life a version gets no security fixes and cloud services stop working. Rocket.Chat also warns that unsupported versions may lose connection to its official mobile and desktop clients. Synapse upgrades can be hard to roll back because of database schema changes, so budget staff time for a tested backup and a staging rehearsal before every upgrade. The cost drivers are the number of environments, the support window you choose, how many people on your team can perform upgrades, and whether you pay a vendor for support.
How to move channels, users and history off Zoom Team Chat
This sequence takes chat history, channels and people from Zoom Team Chat to a self-hosted workspace in a controlled order, so each stage can be checked before Zoom access is removed.
Inventory channels, members and retention needs
The admin lists every chat channel, direct message group and external guest in Zoom Team Chat, with owners, member counts and any retention or legal hold obligations. Zoom's recording formats documentation describes chat as TXT output, so the admin should also confirm how the Zoom export is structured on their account, including whether channel names, timestamps and file attachments are kept. The step is done when the inventory has an owner for each channel and a named decision on which history must be kept.
Export Zoom chat and confirm its structure
An account owner downloads the chat exports Zoom makes available and opens a sample in a text editor. Because chat text arrives as TXT rather than a structured format, the team should check whether each message carries sender, timestamp and thread context, and whether attachments are exported separately. Historical threads may need a conversion script before import. The step is done when a sample channel has been read end to end and the conversion gap is documented.
Confirm the target import path
The platform owner confirms which target fits the exported data. Rocket.Chat's import tools accept full Slack workspace exports, Slack users from CSV and a generic CSV importer, so Zoom chat would need to be converted to CSV. Mattermost data is migrated into Rocket.Chat by converting its export to CSV as well. Mattermost and Element/Synapse have their own import routes, which the team should verify against current documentation. The step is done when the chosen target and the required CSV layout are written down and tested against the sample.
Map users and directory groups
The identity owner matches each Zoom account to a directory identity, usually through Active Directory or LDAP, and decides which directory groups become team or channel membership. Guests and former employees are listed separately so they are not imported by default. Rocket.Chat's paid plans offer LDAP and SAML user group mapping, so the team should confirm which group features its chosen tier includes. The step is done when a mapping table covers every active Zoom user and every exception has an approver.
Pilot with one team
A single team with a known channel set imports its history into a test instance, and its members work in it for a short trial. The pilot checks that message order, timestamps, file links and user identities survive the import, and that people can find the right channels. Issues are logged with the import script version so fixes can be repeated. The step is done when the pilot team signs off on the content and the admin has a repeatable import procedure.
Set single sign-on before cutover
The identity owner connects the chat platform to the corporate identity provider so people sign in with their usual credentials. Synapse supports OpenID Connect, SAML2 and CAS, and Mattermost includes SSO from its Professional plan, while Rocket.Chat's SSO availability depends on the plan chosen. The team should confirm that account deprovisioning follows the directory, so a departed employee cannot keep access. The step is done when test accounts sign in and sign out through SSO and a disabled test account is refused.
Cut over channels and announce the date
The admin imports the remaining channels in the order set by the inventory, reruns the mapping, and tells members where to post from the cutover date. Zoom Team Chat is set to read only for the migrated channels while the final delta is imported. The step is done when each channel has a live counterpart, its members are added, and the owners confirm their channel content is complete.
Retire Zoom chat access
Once the owners confirm the import, the admin removes Zoom Team Chat posting rights, disables chat integrations and bots, and keeps a retained archive of the exported files under the retention rules set in the first step. Meeting links, recordings and notifications that still point to Zoom chat are updated. The step is done when Zoom chat is read only or disabled, the archive location is recorded, and the owners have signed off on the closure.
Trade-offs that decide between chat options
The three chat platforms differ most on scale, availability, federation, client compatibility and upgrade effort. Each card below names one decision and the fact that drives it, so you can match the platform to your user count, uptime needs and operating capacity before you pick a link to your Jitsi or BigBlueButton server.
User count sets the Rocket.Chat architecture
Rocket.Chat's reference architectures suggest one instance with a MongoDB replica set for up to 500 concurrent users. Multiple load-balanced instances linked by NATS are suggested above 500, and Kubernetes microservices with the official Helm chart above 5,000. The multi-instance and microservice designs require a paid plan, so a free Starter or Community workspace stops at the single-instance design. Ask for your peak concurrent user count before you choose.
High availability requires the Mattermost Enterprise tier
Mattermost high availability uses redundant application servers, database servers and load balancers, and it is available only on the Enterprise and Enterprise Advanced plans. A cluster also needs shared file storage on S3, an S3-compatible service or NAS mounted on every node, because local file storage risks corrupting files. If uptime targets are strict, price the paid tier and the shared storage into the design from the start.
Federation needs an explicit domain allowlist
Synapse federates by default on port 8448, and an organization that wants chat with partners must decide which domains may join. The federation_domain_whitelist setting limits federation to listed domains, and an empty list disables it. The docs also recommend firewalling the federation listener. Mattermost and Rocket.Chat do not offer Matrix-style federation, so this decision applies only if you choose Matrix with Element.
Mobile and desktop clients after upgrades
Rocket.Chat warns that an end-of-life version may lose the ability to connect with the official mobile and desktop clients, so staying on a supported line is a user-facing requirement, not just a security one. Confirm with each vendor which client versions work with your server version before you schedule an upgrade, and test a pilot group on the newest client after every change.
Upgrade cadence and rollback limits
Mattermost publishes a new server binary on the 16th of each month, and its ESR line receives longer support. Synapse upgrade notes warn that rolling back can be difficult because schema changes between releases are not always reversible, and Synapse drops support for Python and PostgreSQL versions once they reach upstream end of life. Plan a tested database backup and a staging upgrade path before every release, and assign an owner to track end-of-life dates.
What buyers ask before replacing Zoom Team Chat
What does replacing Zoom Team Chat cost in effort, and which parts are free?
The software license is the smallest part of the bill for most organizations. Mattermost and Rocket.Chat both have free editions, and Matrix servers such as Synapse are distributed under AGPL-3.0 with no license fee for the core. The recurring costs are servers, storage, backups, database administration, upgrades and staff time. Paid items appear when you need features the free tier lacks, such as high availability, air-gapped deployment, or audit features. Mattermost prices its plans by seat license and publishes no prices, and Rocket.Chat prices its paid plans by quote. Ask both vendors for written prices for your user count, and ask DeployOpen for a fixed-scope quote that lists each deliverable separately.
How long do a pilot and cutover take, and what sets that duration?
No supplied figure fixes a duration, so the answer depends on your scope. The main drivers are the number of users and channels, how many identity providers must be connected, whether chat history must be migrated, how many integrations and bots must be rebuilt, and how many change windows your security and operations teams allow. A pilot usually covers one department with real workflows and a rollback path. Cutover then moves users in groups and runs Zoom Team Chat in read-only mode for a period. Ask for the timeline in the written scope, with milestones tied to acceptance tests rather than calendar dates alone.
Can our own team run the platform without outside help?
Yes, if you have people who can operate Linux servers, PostgreSQL or MongoDB, reverse proxies, certificates and backups, and who can apply upgrades on schedule. Mattermost ships as a single Linux binary, which keeps the application footprint small, but high availability requires redundant application servers, database servers and load balancers, and that is available only on its Enterprise and Enterprise Advanced plans. Rocket.Chat's support lifecycle means unsupported versions lose security fixes and may stop connecting to official mobile and desktop clients, so upgrades are a permanent duty. Decide before the pilot who owns patching, monitoring and on-call, and whether outside support is a retainer or a one-off.
What do identity, network and database teams need to provide?
Identity staff connect the platform to your directory and single sign-on. Mattermost includes SSO and AD/LDAP user sync from its Professional plan, and Rocket.Chat's free Starter plan includes LDAP, Active Directory and single sign-on. Network staff must publish HTTPS endpoints, open the ports your chosen deployment uses, and plan how mobile and federated access reaches the server. For Matrix, federation listens on port 8448 by default, and delegation can serve the domain on port 443. Database staff run PostgreSQL for Mattermost and Synapse, or MongoDB 8.0 or later as a replica set for Rocket.Chat, along with replication, backups and restore tests. Ask each team for a sign-off list before the pilot starts.
Can chat history and files move out of Zoom Team Chat?
Usually only partly, and the answer depends on what your Zoom export contains and which target you choose. Rocket.Chat's import tools accept full Slack workspace exports, Slack users from CSV and a generic CSV importer, and Mattermost data is migrated by converting its export into CSV. Zoom's own export formats differ from Slack's, so confirm with Zoom what chat data your account can export and in what format, then test a sample conversion before committing. Meeting recordings are a separate problem: Zoom saves MP4, M4A, TXT, VTT and caption files, which you can download and archive, but they will not appear as chat history in the new platform. Plan storage for them and confirm the retention rules you must keep.
Do the Mattermost or Rocket.Chat free tiers cover our needs?
They can cover small teams with basic messaging, but the limits matter. Mattermost Entry is free, and its calls are limited to 40 minutes, while SSO, AD/LDAP sync and high availability sit on paid plans. Rocket.Chat's free Starter plan allows up to 50 users and includes LDAP, Active Directory, SSO, MFA, end-to-end encryption and retention, but air-gapped deployment and multi-instance designs need a paid plan. The free Community workspace allows up to 100 concurrent users with core messaging. Compare the feature list against your compliance, audit and availability requirements, and get a written statement of what each tier includes before you decide.
Which features does Zoom Team Chat have that need a separate plan?
Map each Zoom Team Chat feature you use, such as channels, file sharing, retention, admin controls and integrations, to a target feature and its license tier before the pilot. Rocket.Chat's paid plans list tamper-evident audit trails and automated failover, and Mattermost's Enterprise plans add high availability and FIPS 140-3 compliance. Matrix on Element Server Suite Community includes Element Call for voice and video alongside Synapse, which may matter if you want chat and calls together. Confirm each mapping in writing with the vendor, because features and plan boundaries change between releases.
How DeployOpen scopes and delivers a chat replacement
DeployOpen plans, implements, integrates, hardens, documents and supports self-hosted open-source platforms inside your own cloud accounts, data centers or air-gapped networks. For a Zoom Team Chat replacement, that means agreeing in writing which chat platform, which meeting link and which identity setup are in scope before any work starts.
How we scope
- Written scope lists the chat platform, user count, channels and any data import from Zoom Team Chat exports.
- Scope states how chat links to your Jitsi or BigBlueButton server, including HTTPS and domain setup.
- Scope names identity integration, such as SSO and directory sync, and which plan features it depends on.
How we build
- We deploy the chosen platform in your environment with its database, file storage and reverse proxy configured.
- We configure the meeting integration so chat users can start calls on your self-hosted video server.
- We run functional and security tests on authentication, file access, federation or licensing settings in scope.
How we hand over
- Deliverables include architecture notes, configuration records, backup and restore procedures and admin runbooks.
- We document the upgrade path for the chosen release line, including support end dates you confirm with the vendor.
- Handover covers administrator training on user onboarding, retention settings and monitoring of the chat service.
How we support
- Engagements are fixed-scope, with scope, deliverables and timelines agreed in writing before work starts.
- Ongoing support, upgrades and continuous testing are available as a retainer after handover.
- Quotes follow from the written scope, so ask us to itemize build, testing, documentation and retainer effort separately.
