If you searched for a Mio alternative in 2026, you're not alone. Mio was the category-defining product for cross-platform chat federation from 2018 through 2024. Google transferred its enterprise messaging interoperability endorsement away from Mio in August 2025, and Mio wound down operations shortly after.

That left a real gap: teams that relied on Mio to bridge Slack and Microsoft Teams suddenly needed a new path forward — without a six-month migration project.

This guide covers what changed, what to evaluate in a replacement, and where TetherChat fits for teams that want direct bridging with sender attribution on both sides.

What Mio did (and why teams used it)

Mio routed messages between chat platforms — primarily Slack, Microsoft Teams, Google Chat, and Zoom. For many organizations, it was the only practical way to keep two sides of a partnership or acquisition talking without forcing everyone onto one platform.

The limitation that frustrated buyers over time: Mio's hub model. For some platform pairs (especially Slack ↔ Teams), both organizations often needed a shared intermediary environment. That added dependency, procurement friction, and a single point of failure.

What to look for in a Mio replacement

When you evaluate Mio alternatives, focus on criteria that matter in production — not feature checklists on a sales deck.

Direct bridging vs. hub routing. Can Slack and Teams connect without both sides sharing Google or Zoom? Direct bridges reduce infrastructure dependency and simplify security reviews.

Sender attribution. Bridged messages should show the sender's name and avatar — not a generic "Incoming Webhook" label or a single shared bot identity on every post.

Bidirectional thread sync. One-way notification pipes are not collaboration. You need replies, threads, and context flowing both ways.

Data handling. If you handle sales conversations, support tickets, or M&A discussions, ask where message content is stored. TetherChat does not store message content — messages are routed in real time, with routing metadata (message IDs for threads, edits, and reactions) retained as needed. File attachments may pass through encrypted transit storage during delivery.

Time to value. Enterprise sales cycles measured in weeks are fine for Fortune 500 procurement. For a team that needs a bridge live before Friday's client call, self-serve setup matters.

Platform breadth. If you only need Slack ↔ Teams, a focused tool works. If you also have Discord communities, developer channels, or acquired subsidiaries on different tools, evaluate whether one vendor covers all pairs.

Mio alternatives worth evaluating in 2026

| Option | Best for | Watch out for | |--------|----------|---------------| | TetherChat | Slack ↔ Teams ↔ Discord bridging with sender attribution; free beta; setup often in about 5–10 minutes | SOC 2 Type II audit in progress (not yet certified) | | NextPlane OpenHub | Google-endorsed Google Chat ↔ Teams workflows | Sales-gated; less self-serve | | Conclude | Slack-native Slack ↔ Teams for teams already deep in Slack | Limited to two platforms | | Slack Connect / Teams External Access | Both orgs on the same platform | Useless when one side is on a different app |

Why teams choose TetherChat over hub-based tools

TetherChat connects Slack, Microsoft Teams, and Discord as official apps on each platform. Bridged messages are delivered with the sender's name and avatar on the other side — not a DIY incoming webhook label.

Not DIY webhooks. Incoming webhooks create one-way, generically labeled posts that break conversational context.

No hub dependency. You don't need both organizations on Google Workspace or Zoom for the bridge to work.

No message content stored. TetherChat relays messages in real time without retaining conversation content — a meaningful difference for privacy-conscious teams.

Free during beta. Unlimited channel bridges, no credit card. Paid plans are coming with plenty of notice.

How to migrate from Mio to TetherChat

You don't need a big-bang cutover. Most teams run this playbook:

Identify your highest-pain channel — the one where missed messages cause the most damage (sales deal room, support escalation, integration war room).
Install TetherChat on Slack (or Discord) and in Microsoft Teams. Allow time for workspace admin approval if required.
Create a Tether with /tether in your Slack or Discord channel. Copy the Tether ID.
Connect from Teams by adding TetherChat as a channel tab and entering the same Tether ID in the configuration form.
Run both bridges in parallel during a transition week if needed, then retire the Mio connection.

For a detailed walkthrough, see our Slack to Teams bridge guide or the step-by-step tutorial.

Compare before you commit

Read our full comparison page for TetherChat vs webhooks, DIY bots, and automation platforms. For more on what changed in the category, see TetherChat vs Slack Connect.

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Ready to replace Mio? Connect Slack to Teams — free beta, no credit card required. Setup often takes about 5–10 minutes per workspace.