Slack Pro alternatives: 6 free & open-source picks
Curated, verified, and actually free. No trials, no crippled tiers. Star counts and last-activity dates checked by hand, not scraped and forgotten.
Canales, hilos, archivos e integraciones para hasta cien usuarios simultáneos; MongoDB es el compañero oculto.
licenseMIT
runsyour server
installDeploy the Community workspace with Docker Compose, Podman, or Kubernetes
dataUsers, rooms, messages, and most metadata live in MongoDB; uploads live on local storage or a configured object-storage backend.
the catch vs Slack ProRocket.Chat Community covers channels, threads, files, and integrations, but it adds MongoDB operations, a 100-concurrent-user limit, and a much smaller ecosystem than Slack.
setupA production installation requires MongoDB, DNS/TLS, email, backups, upgrades, and enough capacity planning to stay within the Community plan's 100-concurrent-user limit.
facts verified 2026-08-10
Chat con forma de Slack para menos de 250 usuarios, autoalojado; la suscripción desaparece y aparece la guardia.
licenseMIT
runsyour server
installInstall the official Linux binary with PostgreSQL, then configure systemd, TLS/reverse proxy, SMTP, and file storage
dataChannels, posts, users, and configuration live in PostgreSQL; file attachments live in the Mattermost data directory or configured S3-compatible object storage.
the catch vs Slack ProMattermost Team Edition closely resembles Slack, but self-hosting adds database, email, storage, backup, upgrade, and uptime work while enterprise identity and compliance remain paid.
setupThe first obstacle is a real Linux service deployment, PostgreSQL, SMTP, DNS/TLS, storage, backups, and upgrades, not an app-store install.
facts verified 2026-08-10
Chat de equipo centrado en temas con historial completo y excelente búsqueda; sobreviven menos mensajes al paso.
Salas, hilos, archivos y llamadas cifradas en Matrix; el servicio público gratuito te evita gestionar un servidor.
licenseAGPL-3.0-or later OR GPL-3.0+
runsyour machine or their cloud
installUse a free Matrix account in Element Web/mobile/desktop, or deploy Element Server Suite on your own infrastructure
dataRooms, event history, account data, and media live on the selected Matrix homeserver; encrypted-room keys remain on clients and can be backed up through Matrix's key-backup system.
the catch vs Slack ProElement provides rooms, threads, files, calls, and encryption, but Matrix is less familiar and its workplace app and integration ecosystem is much smaller than Slack's.
setupThe clean hosted path is easy, but self-hosting the current Element Server Suite means operating a Matrix homeserver and its Kubernetes/Helm-based stack.
facts verified 2026-08-10
Cinco usuarios obtienen historial, archivos, tareas y llamadas uno a uno ilimitados; los equipos más grandes se topan con el muro de pago.
licenseproprietary, free
runstheir cloud
installHosted signup; use Chanty's web, desktop, or mobile clients
dataChats, task records, users, and files live in Chanty's cloud; workspace data export is a Business-plan feature rather than part of the free plan.
the catch vs Slack ProChanty Free offers unlimited history and useful tasks, but five-member capacity, no free data export, and a far smaller integration ecosystem make it a narrow Slack Pro substitute.
setupThere is no technical setup blocker, but the free workspace is limited to five members, so the sixth teammate forces a migration or payment.
facts verified 2026-08-10
Usuarios, canales e historial ilimitados con diez gigabytes en total; las reuniones grupales y las integraciones serias aún cuestan.
licenseproprietary, free
runstheir cloud
installHosted signup; use the browser or Pumble's desktop/mobile apps
dataMessages, channels, user records, and files live in Pumble's cloud; workspace owners can export public-channel data as a ZIP with message data and file links.
the catch vs Slack ProPumble Free keeps unlimited users and history, but group meetings, screen sharing, integration breadth, storage, and Slack's huge app ecosystem are materially weaker.
setupThere is no installation hurdle, but migration still requires inviting everyone and rebuilding channels and integrations; free exports exclude private channels and direct messages.
facts verified 2026-08-10
last updated 2026-08-10 · no votes, no pay-to-list · just what's real
| tool | license | running it | platforms | stars | active |
|---|---|---|---|---|---|
| Rocket.Chat Community | MIT | self-host, real ops | web, macos, windows, linux, ios, android, self-hosted | 45,900 | 2026-08 |
| Mattermost Team Edition | MIT | self-host, real ops | web, macos, windows, linux, ios, android, self-hosted | 38,700 | 2026-08 |
| Zulip | open source | self-host, real ops | web, macos, windows, linux, ios, android, self-hosted | 25,600 | 2026-08 |
| Element | AGPL-3.0-or later OR GPL-3.0+ | they host it | web, macos, windows, linux, ios, android, self-hosted | 13,300 | 2026-07 |
| Chanty Free | proprietary, free | they host it | web, macos, windows, linux, ios, android | — | — |
| Pumble Free | proprietary, free | they host it | web, macos, windows, linux, ios, android | — | — |
People still pay for Slack Pro because community software is valuable when members are already there and the operator does not have to own realtime reliability and abuse response. The recurring cost buys realtime delivery, notifications, abuse handling, search, media, permissions, mobile clients, backups, and community operations, not just the visible interface. If none of that applies to you, any pick above saves $105 a year.
Is there a free alternative to Slack Pro?
Yes: Rocket.Chat Community, Mattermost Team Edition, Zulip and 3 more. Every tool on this page is either open source or genuinely free to use long-term: no trials, no crippled tiers.
Should I just build my own Slack Pro?
Our verdict is NO TANTO. A consolation build is possible, but the paid product's decisive value sits outside a solo rebuild. For Slack Pro, run a small private team chat with channels, threads, files, and search. The hard boundary is existing team network, integrations, push delivery, enterprise controls, and global reliability, plus network, moderation, and communication infrastructure. If you'd rather build, the exact one-shot prompt is free at puedovibecodearlo.app/slack-pro.
