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Comparison · Mkt Auto

Customer.io vs Sulu

A side-by-side editorial comparison of Customer.io and Sulu — release velocity, themes, recent moves, and the top alternatives to consider.

Customer.io vs Sulu: at a glance

FeatureCustomer.ioSulu
SectorMkt AutoMkt Auto
Velocity score7.55.0
Sparks · 30d20
Top themesgeofencing, llm knowledge, byo sms, live notificationssymfony-cms, dual-branch-releases, ckeditor, doctrine-migrations
Last editorial update1d ago1h ago
WebsiteVisit →

What is Customer.io?

Location becomes a trigger, Twilio stops being the only SMS path, and the LLM layer gets a memory

The summer window widens both ends of the automation graph. On the input side, geofences turn physical entry and exit into workflow triggers and date triggers now read attributes off custom objects; on the output side, SMS opens to Sinch, Infobip, and Vonage instead of Twilio alone, and live notifications add a persistent, continuously updating message format on iOS and Android. The LLM side gains a workspace-scoped Knowledge Library that both LLM actions and the Agent can read, replacing per-prompt copy-paste. Channel-based message limits and unsubscribe-preserving profile merges tighten the send-side guardrails underneath all of it.

Read the full Customer.io trajectory →

What is Sulu?

Sulu ships 2.6 and 3.0 in lockstep, and the 3.0 line still reads like a maintenance branch.

Sulu is a Symfony-based CMS for developer-built sites, and its release process is a synchronised pair: every 3.0.x patch ships within a minute of the matching 2.6.x patch, carrying largely the same pull requests. Six releases in five months — 3.0.8/2.6.25, 3.0.7/2.6.24, 3.0.6/2.6.23 — are almost entirely fixes, editor upgrades and framework compatibility work. A security advisory was patched across both branches in March.

Read the full Sulu trajectory →

Customer.io vs Sulu: editorial side-by-side

C
Customer.io
MKT AUTO
7.5

Location becomes a trigger, Twilio stops being the only SMS path, and the LLM layer gets a memory

◆ Current state

The summer window widens both ends of the automation graph. On the input side, geofences turn physical entry and exit into workflow triggers and date triggers now read attributes off custom objects; on the output side, SMS opens to Sinch, Infobip, and Vonage instead of Twilio alone, and live notifications add a persistent, continuously updating message format on iOS and Android. The LLM side gains a workspace-scoped Knowledge Library that both LLM actions and the Agent can read, replacing per-prompt copy-paste. Channel-based message limits and unsubscribe-preserving profile merges tighten the send-side guardrails underneath all of it.

◆ Where it's heading

Customer.io is systematically loosening the assumptions its automation graph was built on: one workspace one app, one SMS vendor, one blunt frequency cap, prompts as the only place LLM context can live. Each release swaps a hardcoded shape for a configurable one, which is what a platform does when its largest accounts have outgrown the original model. The AI work follows the same instinct — not a chatbot bolted on, but retrieval and context turned into workspace-level objects that the rest of the system can reference.

◆ Prediction

Expect the Knowledge Library to spread past LLM actions into more of the Agent's surface, and the per-channel controls to keep filling in — the release notes name WhatsApp and SMS capping outside Twilio as a live gap, which is an odd thing to leave open right after opening SMS to three new vendors.

S
Sulu
MKT AUTO
5.0

Sulu ships 2.6 and 3.0 in lockstep, and the 3.0 line still reads like a maintenance branch.

◆ Current state

Sulu is a Symfony-based CMS for developer-built sites, and its release process is a synchronised pair: every 3.0.x patch ships within a minute of the matching 2.6.x patch, carrying largely the same pull requests. Six releases in five months — 3.0.8/2.6.25, 3.0.7/2.6.24, 3.0.6/2.6.23 — are almost entirely fixes, editor upgrades and framework compatibility work. A security advisory was patched across both branches in March.

◆ Where it's heading

Three threads run through the pairs. Editor upkeep is constant, with CKEditor moving to 47 LTS and then 48 and the fallout — table widgets, webpack font builds — fixed release by release. Framework compatibility is the second: Request->get calls replaced for Symfony 8, PHPUnit 13 and PHPStan kept green on lowest dependencies. The third and most interesting is data-model cleanup on the 3.0 side, where tags migrated from names to IDs behind a newly added DoctrineMigrationsBundle, with smart-content filters reworked to match. What is not visible is any capability that exists on 3.0 and not on 2.6 — a major version that is not yet behaving like one.

◆ Prediction

Expect the paired-release rhythm to continue with more Symfony 8 preparation and CKEditor 48 fallout. The open question is when 3.0 starts receiving work that is not upmerged from 2.6; until then the major version number is not buying users anything.

Alternatives to Customer.io and Sulu

Other Mkt Auto 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 Customer.io or Sulu.

See all Customer.io alternatives → · See all Sulu alternatives →

Recent activity from Customer.io and Sulu

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

  1. 2d agoCustomer.ioAdd reusable knowledge sources to LLM actions
  2. 2d agoCustomer.ioSet up SMS with Sinch, Infobip, or Vonage
  3. 2d agoCustomer.ioSummer recap: geofences, live notifications, inbox, SMS providers
  4. 2d agoCustomer.ioGeofences: message people when they enter or exit a location
  5. 3d agoCustomer.ioSend push notifications to multiple mobile apps in one workspace
  6. 8d agoCustomer.ioLive notifications: real-time updates without opening your app
  7. 15d agoSuluSulu 3.0.8 validates selection filter params at build time
  8. 15d agoSuluSulu 2.6.25 adds a redirect after SSO login
  9. 2mo agoSuluSulu 3.0.7 fixes smart-content filtering and speeds up indexing
  10. 2mo agoSuluSulu 2.6.24 upgrades CKEditor to version 48
  11. 2mo agoSuluSulu 3.0.6 migrates tag names to IDs with Doctrine migrations
  12. 2mo agoSuluSulu 2.6.23 moves to CKEditor 47 LTS and preps Symfony 8

Frequently asked questions

What is the difference between Customer.io and Sulu?

They serve adjacent needs but don't currently overlap on shipped themes. Customer.io is currently shipping more aggressively (velocity 7.5 vs 5.0), with 2 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 Customer.io better than Sulu?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Customer.io is currently shipping more aggressively (velocity 7.5 vs 5.0), with 2 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Mkt Auto products to evaluate alongside.

What are the best alternatives to Customer.io?

Top Customer.io alternatives in Mkt Auto are ranked by recent ship velocity. Browse the "Customer.io alternatives" section above for the current picks, or visit /alternatives/customer-io for the full list with editorial commentary on each.

What are the best alternatives to Sulu?

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