Rspamd
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Comparison · Comms
Delta Chat vs Slack
A side-by-side editorial comparison of Delta Chat and Slack — release velocity, themes, recent moves, and the top alternatives to consider.
Delta Chat vs Slack: at a glance
What is Delta Chat?
Delta Chat is quietly replacing its email identity with relays
Delta Chat desktop v2.65.0 adds pinned messages, message multiselect actions and a System default language option, and hides individual reactions from channel owners. v2.62.0 changed more of the foundation: relays can be removed, the default relay setting is gone, onboarding adds several relays, and email addresses are no longer shown for profiles. Contacts are also no longer shown as verified.
What is Slack?
Slack now hosts any A2A agent without Slack-specific code.
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
Delta Chat vs Slack: editorial side-by-side
Delta Chat
5.0COMMS
Delta Chat is quietly replacing its email identity with relays
◆ Current state
Delta Chat desktop v2.65.0 adds pinned messages, message multiselect actions and a System default language option, and hides individual reactions from channel owners. v2.62.0 changed more of the foundation: relays can be removed, the default relay setting is gone, onboarding adds several relays, and email addresses are no longer shown for profiles. Contacts are also no longer shown as verified.
◆ Where it's heading
The project is removing email from what users see and from how they think about identity, with relays taking its place as multi-path infrastructure. Fetching from every relay and sending through the fastest one treats a relay as replaceable, which matters for a federated messenger. Around that, the client keeps closing feature gaps with mainstream messengers through pinning, channel reactions and better group notification handling.
◆ Prediction
Expect further relay management work, as the core notes show this is where the structural change is. Channels are the next most active surface, with reaction privacy already changing there.
Slack
6.3COMMSCOLLAB
Slack now hosts any A2A agent without Slack-specific code.
◆ Current state
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
◆ Where it's heading
Slack is lowering the cost of putting outside agents in front of its users: first skills as code, then MCP pointers for coding agents, now a standard protocol in place of the Slack app model for agents. The platform is positioning itself as the place where agents built anywhere meet the people who use them.
◆ Prediction
Expect more A2A follow-ups, such as agents appearing in Slackbot or skills surfaces and richer Agent Card features, given how fast the agent releases have stacked up since October.
Alternatives to Delta Chat 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 Delta Chat or Slack.
Twilio
Twilio's voice AI stops cutting callers off mid-sentence, using its own turn-taking model.
Salesmsg
Salesmsg adds call-back requests and a one-click Emergency Stop for all outbound texts.
Element
Element 1.12.35 follows the call picture-in-picture release with one desktop storage fix.
Krisp
Krisp moves call transcripts and live captions to cloud transcription in KrispCX 2.84.4.
Misskey
Misskey 2026.11 ships: a leaner start script, and Node.js 22 no longer boots.
See all Delta Chat alternatives → · See all Slack alternatives →
Recent activity from Delta Chat and Slack
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 4d agoSlackBring your A2A agents to Slack ⚡
- 8d agoSlackWork Objects embeds require the slack-mcps.com frame ancestor
- 10d agoSlackSlack CLI 4.13 tells coding agents about Slack MCP and Skills
- 10d agoSlackSlack Skills Plugin installs in Claude Code from its own marketplace
- 12d agoSlackUpdated low-usage submission criteria for Slack Marketplace apps
- 15d agoSlackSlack CLI 4.12.0, the fourth CLI release in October
- 17d agoDelta ChatPinned messages arrive; channel reactions become anonymous totals
- 1mo agoDelta ChatMulti-relay onboarding; email addresses leave the profile list
- 2mo agoDelta ChatFixes the 2.59.0 unread-sync bug; Arabic, Telugu, Slovenian added
- 3mo agoDelta ChatChannel post reactions and experimental Team Profiles
- 3mo agoDelta Chatv2.57.0 release preparation
- 3mo agoDelta ChatOAuth removed; group member search and command palette added
Frequently asked questions
What is the difference between Delta Chat and Slack?
They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), 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 Delta Chat 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 5.0), 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 Delta Chat?
Top Delta Chat alternatives in Comms are ranked by recent ship velocity. Browse the "Delta Chat alternatives" section above for the current picks, or visit /alternatives/deltachat 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.