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Comparison · Comms

Converse.js vs Slack

A side-by-side editorial comparison of Converse.js and Slack — release velocity, themes, recent moves, and the top alternatives to consider.

Converse.js vs Slack: at a glance

FeatureConverse.jsSlack
SectorCommsComms, Collab
Velocity score0.06.3
Sparks · 30d01
Top themesxmpp, omemo-encryption, e2e-usability, pubsub-apiagents, mcp, developer-platform, marketplace
Last editorial update1mo ago15d ago
WebsiteVisit →Visit →

What is Converse.js?

Converse.js 14 lands OMEMO:2 — the browser XMPP client catches up on modern encryption.

Converse.js reached 14.0.0 in June 2026 after a tight beta train, and the release is defined by one thing: support for OMEMO:2, the current revision of XMPP's end-to-end encryption. The surrounding work is all encryption ergonomics — per-chat encryption state remembered across chat-close and re-login, an explicit error surfaced for undecryptable messages instead of silently dropping them, the toggle hidden on untrusted devices, and original filenames preserved on encrypted image download. New PubSub API methods for create, subscribe and unsubscribe round out the release.

Read the full Converse.js trajectory →

What is Slack?

Slack raises the Marketplace bar back to ten installs while the agent platform consolidates.

Slack's developer platform runs two tracks. The agent build-out has produced a spark roughly every two weeks since June — MCP client, a skills plugin targeting Claude Code and Cursor, and Slack Code — and now has a consolidation date attached: assistant_view is deprecated in February 2027, replaced by an Agent Sessions API. The second track is platform administration and tooling, and this window belongs to it: Marketplace submissions again require at least ten installed active workspaces, held throughout the review, after a period at a lower temporary threshold. The CLI has shipped three times since late July.

Read the full Slack trajectory →

Converse.js vs Slack: editorial side-by-side

C0.0

Converse.js 14 lands OMEMO:2 — the browser XMPP client catches up on modern encryption.

◆ Current state

Converse.js reached 14.0.0 in June 2026 after a tight beta train, and the release is defined by one thing: support for OMEMO:2, the current revision of XMPP's end-to-end encryption. The surrounding work is all encryption ergonomics — per-chat encryption state remembered across chat-close and re-login, an explicit error surfaced for undecryptable messages instead of silently dropping them, the toggle hidden on untrusted devices, and original filenames preserved on encrypted image download. New PubSub API methods for create, subscribe and unsubscribe round out the release.

◆ Where it's heading

The project is closing the gap between having encryption and having usable encryption. Almost every OMEMO change in this cycle is about failure modes users previously had to guess at: a silently dropped message, an encryption toggle offered where it cannot work, an abandoned bundle that never self-healed. That is the work a client does when its encryption is no longer a demo but something people depend on daily. Dropping client-compress for native browser APIs points the same way — fewer bundled dependencies in a security-sensitive path.

◆ Prediction

Expect the 14.x line to settle into interoperability fixes as OMEMO:2 meets other XMPP clients in the wild, with the new PubSub API the most likely base for the next feature layer.

Slack logo
Slack
COMMSCOLLAB
6.3

Slack raises the Marketplace bar back to ten installs while the agent platform consolidates.

◆ Current state

Slack's developer platform runs two tracks. The agent build-out has produced a spark roughly every two weeks since June — MCP client, a skills plugin targeting Claude Code and Cursor, and Slack Code — and now has a consolidation date attached: assistant_view is deprecated in February 2027, replaced by an Agent Sessions API. The second track is platform administration and tooling, and this window belongs to it: Marketplace submissions again require at least ten installed active workspaces, held throughout the review, after a period at a lower temporary threshold. The CLI has shipped three times since late July.

◆ Where it's heading

The install requirement moving back up is a distribution decision arriving in the middle of a platform push, and the two point the same way. Slack is making it easier to build agents and harder to list one, which favours developers who already have distribution — existing workspace tools and vendors — over a new app hoping the Marketplace supplies its first users. Combined with the assistant deprecation and the Agent Sessions API, the platform is narrowing on one agent surface and one class of builder rather than widening the funnel.

◆ Prediction

The threshold is described as a return from a temporary lower bar rather than a new policy, so the open question is what replaces the Marketplace as the discovery path for an app that cannot reach ten workspaces on its own. These entries do not answer it.

Alternatives to Converse.js and Slack

Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Converse.js or Slack.

See all Converse.js alternatives → · See all Slack alternatives →

Recent activity from Converse.js and Slack

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 16d agoSlackUpdated installation requirement for Slack Marketplace apps
  2. 17d agoSlackCLI adds app-approval status checks and custom app icons
  3. 28d agoSlackAnnouncing Slack Code
  4. 28d agoSlackAgent Sessions API replaces assistant_view, deprecated Feb 2027
  5. 1mo agoSlackAnnouncing the Slack MCP and Skills Plugin
  6. 1mo agoSlackCLI adds manifest diff and a Block Kit preview command
  7. 2mo agoConverse.jsOMEMO:2 encryption support ships in Converse 14
  8. 2mo agoConverse.jsOMEMO bundle self-healing and new PubSub API methods
  9. 3mo agoConverse.jslibomemo.js dependency bump
  10. 3mo agoConverse.jsclient-compress replaced with native browser APIs
  11. 3mo agoConverse.jsFirst beta carrying the OMEMO usability fixes
  12. 3mo agoConverse.jsReaction attribution and MUC JID parsing fixes

Frequently asked questions

What is the difference between Converse.js and Slack?

They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is Converse.js better than Slack?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.

What are the best alternatives to Converse.js?

Top Converse.js alternatives in Comms are ranked by recent ship velocity. Browse the "Converse.js alternatives" section above for the current picks, or visit /alternatives/converse-js for the full list with editorial commentary on each.

What are the best alternatives to Slack?

Top Slack alternatives in Comms are ranked by recent ship velocity. Browse the "Slack alternatives" section above for the current picks, or visit /alternatives/slack for the full list with editorial commentary on each.