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How much does it cost to build an app like Slack?

A team chat MVP like Slack typically costs $28k–42k and takes 15–21 weeks, covering web, Android and iOS apps with workspaces, public and private channels, threads, direct messages, file sharing, search, per-seat billing and an admin console.

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2026 estimate · first release

$28k–$42k

Timeline
15–21 weeks
MVP features
8 core features
Typical team
5-7 people: product manager, designer, a web developer, a Flutter or React Native developer, 2 backend developers, QA

Cumulative cost by tier

  • MVP$28k–$42k
  • + Growth$40k–$57k
  • + Scale$90k–$177k

Productivity · cost guide

Where the money goes in an app like Slack.

Slack is a trademark of its owner. Nexzem is not affiliated with Slack; the name only describes the type of product. Figures are 2026 estimates for building a comparable product with an experienced Indian team, converted to USD, not what any company spent.

Team chat is a business product, and businesses buy differently from consumers. They ask about single sign-on, data retention, exports, audit logs and where data is stored before they ask about emoji. They also expect the tool to connect to everything else they use. That combination of real-time messaging, deep search, integrations and enterprise controls is what puts even the first release in the mid-sized band of our app cost calculator.

New team chat products usually target a group that general tools serve poorly: frontline and shift workers, regulated industries that need self-hosting, a vertical such as healthcare or construction, or a company that wants chat built into its own platform. Our SaaS development team scopes the first release around that buyer.

Live estimate

Pick a scope, watch the estimate move.

Features are grouped into three tiers you would ship in order. Each tier maps to a band in our app cost calculator, so the numbers agree everywhere on this site.

MVP

+$28k–$42k

First public release

  • Workspaces and sign-inEmail and Google or Microsoft sign-in, invites, guest accounts and workspace settings.
  • Channels and direct messagesPublic and private channels, group and one-to-one messages, mentions and reactions.
  • ThreadsReply in threads with follow and unfollow, so channels stay readable.
  • Files and previewsUpload and preview images, PDFs and documents, with virus scanning and storage limits.
  • SearchFull-text search across messages and files with filters by channel, person and date.
  • NotificationsPush, desktop and email alerts with per-channel preferences, keywords and do-not-disturb.
  • Per-seat billingFree and paid plans with seat counts, invoices and upgrades.
  • Admin consoleMembers, roles, channel management, retention settings and exports.

Growth

+$12k–$15k

After launch traction

  • Integrations and bot APIIncoming webhooks, slash commands, OAuth apps and connectors for common tools.
  • Audio and video huddlesDrop-in calls with screen sharing through a WebRTC SFU.
  • AI search and summariesAnswers from workspace messages with links to sources, and channel and thread recaps.
  • Desktop appsWindows and macOS apps with native notifications and multiple workspaces.
  • Workspace analyticsActive members, message volume and channel activity for admins.

Scale

+$50k–$120k

Market leader territory

  • SSO, SCIM and enterprise adminSAML or OIDC single sign-on, automated provisioning and multi-workspace organisations.
  • Compliance and eDiscoveryLegal holds, retention policies, exports, audit logs and data loss prevention.
  • Shared channels across companiesChannels shared between organisations with separate admin control.
  • Workflow automation and AI agentsNo-code workflows and AI agents that act in connected tools through governed integrations.
  • Data residency and customer-managed keysRegion selection and encryption keys controlled by the customer.

Timeline

From kickoff to the app stores.

15–21 weeks and $28k–$42k for the first release, planned in two-week sprints with a demo at every milestone.

  1. 01Discovery

    2–3 wks · $3k–$4k

    Target buyer, security requirements, tenancy model, retention rules, integration priorities and architecture.

  2. 02UX and UI design

    3–4 wks · $5k–$7k

    Sidebar, channel, thread, search, files and admin flows on web and mobile.

  3. 03Build

    7–10 wks · $15k–$24k

    Real-time service, channels and threads, files, search, notifications, billing and admin console.

  4. 04QA and pilot

    2–3 wks · $3k–$5k

    Permission and tenancy tests, load tests, security testing and a pilot with real teams.

  5. 05Launch

    1–1 wks · $2k–$2k

    Store submissions, onboarding emails, monitoring and launch support.

Then Growth: +8–12 weeks, +$12k–$15k. Integrations and a bot API, huddles, AI search and summaries, desktop apps and workspace analytics.

Then Scale: +16–28 weeks, +$50k–$120k. SSO and SCIM, compliance and eDiscovery, shared channels, workflows and AI agents, data residency and customer-managed keys.

Tech stack

A current stack for an app like Slack.

What we would reach for in 2026. Every layer has alternatives; the right pick depends on your team, budget and markets.

  • Clients

    • React or Next.js web app
    • Electron or Tauri desktop
    • Flutter or React Native

    One web client powers browser and desktop; phones share one codebase.

  • Real-time backend

    • Elixir (Phoenix), Go or Node.js
    • WebSockets
    • FCM and APNs

    Many long-lived connections per workspace, with push and email for people who are away.

  • Data

    • PostgreSQL with tenant isolation
    • Redis or Valkey
    • Object storage for files

    A clear tenant boundary in every table and query is the foundation for enterprise security reviews.

  • Search

    • OpenSearch or Elasticsearch
    • Embeddings and hybrid search for AI answers

    Fast keyword search respecting channel permissions, plus semantic retrieval for AI answers.

  • Identity and integrations

    • SAML and OIDC SSO
    • SCIM provisioning
    • OAuth 2.0 apps and webhooks
    • MCP for AI tools

    Enterprises connect identity and tools in standard ways, and AI agents need governed access to the same tools.

  • Cloud and ops

    • AWS, Azure or Google Cloud
    • Terraform
    • OpenTelemetry + Grafana
    • Sentry

    Infrastructure as code and good observability make SOC 2 audits and regional deployments manageable.

Cost drivers

What moves the number.

Most of the price is engineering time. These are the parts of this product that take the most of it.

  1. 01

    Multi-tenancy and permissions

    Every message, file and search result must respect workspace and channel boundaries. Designing tenant isolation correctly from the start is far cheaper than retrofitting it; our guide to multi-tenant SaaS architecture covers the options.

  2. 02

    Search at depth

    Teams expect to find a message from last year in seconds, with permissions applied. Indexing messages and files, and keeping the index in sync with edits and deletions, is substantial backend work.

  3. 03

    Integrations

    Buyers judge team chat by how it connects to their tools. Webhooks, a bot API, OAuth apps and a handful of first-party connectors are a product in their own right.

  4. 04

    Enterprise requirements

    SSO, SCIM, retention, legal holds, exports, audit logs and data residency often decide large deals. They sit in the scale tier but should be planned in the data model from day one.

  5. 05

    Security reviews

    Business customers send security questionnaires and ask for a SOC 2 report. Budget for security testing, policies and audit preparation alongside the code.

  6. 06

    AI with permissions

    AI answers must only use messages the asking user can see. Permission-aware retrieval, source links and admin controls for AI are what make it usable in companies.

Monetisation

How products like this make money.

Decide the model before the build: it changes the payment flows, the admin panel and sometimes the app store rules you work under.

  • 1

    Per-seat subscriptions

    Monthly or annual price per active member, with a free tier limited by history or integrations.

  • 2

    Enterprise plans

    Higher prices for SSO, compliance, data residency and support commitments.

  • 3

    AI add-on

    Search answers, recaps and agents sold as an upgrade per seat or by usage.

  • 4

    Self-hosted licences

    Annual licences for organisations that must run chat in their own infrastructure.

Deep dive

Pick the buyer general tools ignore

General team chat is dominated by large suites, so a new product needs a clear reason to exist. Strong options include frontline teams who work on phones in shifts, regulated organisations that need on-premise or sovereign hosting, industries that need chat tied to their records, and software companies that want chat embedded in their own product for their customers.

Each of those buyers changes the MVP. Frontline teams need shift-aware notifications and simple onboarding without corporate email. Regulated buyers need retention, exports and audit logs early. Embedded chat needs an SDK and an API rather than a standalone app. Our product discovery work makes that choice explicit before the build starts.

How real-time delivery and unread state work

Each client keeps a WebSocket open to the real-time service and subscribes to the workspaces it belongs to. A new message is stored, assigned a sequence number within its channel and pushed to connected members; members who are away receive push or email according to their preferences. Clients that reconnect ask for everything after the last sequence they saw.

Unread counts and mention badges look trivial and are not. Each member has a read position per channel, updated across devices, and badges must agree on web, desktop and phone. Store read positions separately from messages and update them in batches to keep write volume manageable.

  • Make message sends idempotent with a client-generated ID, so retries never duplicate messages.
  • Fan out to connected clients only; let disconnected clients catch up on reconnect.
  • Treat edits and deletes as events so search, previews and notifications stay consistent.

Integrations, bots and AI agents

Team chat becomes a hub when other tools can post into it and act from it. The basics are incoming webhooks, slash commands, interactive buttons and an OAuth app model with scoped permissions. Connectors for a few tools your buyers use, such as issue trackers, CRMs and calendars, deliver value on day one.

AI is the newest layer. Permission-aware search that answers questions with links to the source messages is the most useful first step, followed by recaps of busy channels. Agents that take actions in connected tools need governance: scoped credentials, approvals for sensitive actions and logs. Standards such as the Model Context Protocol make it easier to connect AI to tools consistently, and our AI agent development team builds on them.

Security, compliance and enterprise sales

Companies trust team chat with their most candid conversations, so security is part of the product. Encrypt data in transit and at rest, isolate tenants rigorously, log administrative actions and support SSO early. A SOC 2 report is a common requirement for mid-market and enterprise deals, and preparing for it shapes processes as much as code.

Compliance features follow buyers. Retention policies and exports matter for regulated industries, legal holds for litigation, data residency for European and public-sector customers and customer-managed keys for the most sensitive. Personal data in messages is covered by the GDPR and India's DPDP Act, so deletion and access requests must work across messages, files and search indexes.

Running costs

Text messages are cheap to store; files and search indexes are not. The main lines are connection servers, the database, file storage, the search cluster, push and email delivery, call infrastructure for huddles and AI inference. Free-tier limits on history and storage keep costs aligned with revenue.

Maintenance is roughly 15-20% of the build cost per year, plus infrastructure and the ongoing work of security reviews and compliance. Our application maintenance and support team usually stays involved as enterprise features are added.

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Related services and expertise.

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Building an app like Slack: questions

Something else on your mind? Ask a consultant and get a reply within one business day.

How much does it cost to build an app like Slack?

A team chat MVP with web, Android and iOS apps, workspaces, channels, threads, direct messages, files, search, billing and admin costs roughly $28k–42k with an experienced Indian team. Adding integrations, huddles, AI search and summaries, desktop apps and analytics brings the total to about $40k–57k. SSO and SCIM, eDiscovery, shared channels and data residency take the total past $90k. These are estimates for a comparable product.

How long does it take to build a team chat app?

About 15–21 weeks to a first release on web and mobile. Growth features typically add 8–12 weeks, and enterprise controls are a further phase driven by the customers you sign. Their security questionnaires often decide the order in which those features are built.

Should I build team chat or use an existing tool?

For internal use, an existing tool or a self-hosted open-source option is usually cheaper. Building makes sense when chat is your product, when you need it embedded in your own platform or when regulations require control that existing tools cannot offer. See SaaS vs custom software.

Can I offer a self-hosted version?

Yes, if you plan for it. Containerised services, configuration instead of hard-coded cloud services and an upgrade process customers can run themselves are needed. Self-hosted licences are a strong selling point for regulated buyers. Budget for support, because customers running your software on their own servers will need help with upgrades, backups and scaling.

How do AI features work in team chat?

Messages are indexed for semantic and keyword search, and a language model answers questions or writes recaps using only messages the user is allowed to see, with links to the sources. Agents that take actions in other tools need scoped credentials and approval steps.

What security features do business customers expect?

SSO, two-factor authentication, encryption in transit and at rest, audit logs, retention policies, exports, role-based admin and a SOC 2 report. Larger customers add SCIM provisioning, data residency and customer-managed keys.

Which tech stack suits a team chat app?

A React or Next.js web client wrapped for desktop, Flutter or React Native apps, an Elixir, Go or Node.js real-time service over WebSockets, PostgreSQL with tenant isolation, OpenSearch or Elasticsearch and object storage for files. See Firebase vs Supabase if you are considering a managed backend for a smaller product.

How do integrations work?

Through webhooks that post messages, slash commands and interactive buttons that call your service, and OAuth apps with scoped permissions. Most products also build a handful of first-party connectors for the tools their buyers rely on most. A public directory of apps, with review before listing, helps customers find integrations and protects them from poorly built ones.

How do team chat apps make money?

Per-seat subscriptions with a free tier, enterprise plans for compliance and security features, AI add-ons and self-hosted licences for organisations that must run their own infrastructure. Free tiers drive adoption, so limit history rather than core features.

Is Nexzem affiliated with Slack?

No. Slack is a trademark of its owner, and we use the name only to describe a type of product. The figures are estimates for building a comparable team chat app, not what any company spent.

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Planning an app like Slack?

Send us this scope and a consultant will turn it into a feature-level estimate for your market, usually within 48 hours of a free consultation.

Send this scopeTune it in the calculator
First release
$28k–$42k
To launch
15–21 weeks
Full scale
$90k+
Upkeep / year
15–20% of build