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Comparison · Mkt Auto
Buttondown vs Sulu
A side-by-side editorial comparison of Buttondown and Sulu — release velocity, themes, recent moves, and the top alternatives to consider.
Buttondown vs Sulu: at a glance
What is Buttondown?
Buttondown documents its events API, opening dashboard analytics to anyone who wants to pull them
The changelog is a near-daily log of two to four items, overwhelmingly fixes, many crediting the reporter by name. The newest entry breaks that shape: the events API is now documented, so deliveries, opens and clicks can be pulled programmatically at the same granularity the dashboard shows. Around it is the usual queue work — an RSS-to-email rollup bug traced to a 2023 kludge, duplicate subscribe-form options removed as a footgun, a change_email_address automation taught to skip cleanly when the address is already taken.
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.
Buttondown vs Sulu: editorial side-by-side
Buttondown
5.0MKT AUTO
Buttondown documents its events API, opening dashboard analytics to anyone who wants to pull them
◆ Current state
The changelog is a near-daily log of two to four items, overwhelmingly fixes, many crediting the reporter by name. The newest entry breaks that shape: the events API is now documented, so deliveries, opens and clicks can be pulled programmatically at the same granularity the dashboard shows. Around it is the usual queue work — an RSS-to-email rollup bug traced to a 2023 kludge, duplicate subscribe-form options removed as a footgun, a change_email_address automation taught to skip cleanly when the address is already taken.
◆ Where it's heading
The through-line has been converting quiet-wrong behaviour into loud-correct behaviour: automations that skipped sends silently, resubscribes that changed state without saying so, cross-posts marked failed after they published. Documenting the events API is the same instinct pointed outward — data the product already had, made reachable instead of implied. The editor still generates the largest share of reported bugs, and that has not changed.
◆ Prediction
Expect the API surface to keep getting documented rather than expanded, since the events endpoint already existed, and the editor to keep producing the bulk of the fix queue at the current near-daily cadence.
Sulu
5.0MKT AUTO
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 Buttondown 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 Buttondown or Sulu.
GetResponse
Ecommerce blocks keep landing while open tracking gets a regulatory escape hatch
Gumloop
The reporting layer arrives, and it counts what agents did and what they cost.
Customer.io
The AI agent moves into Slack, so operating Customer.io no longer means opening it.
n8n
Four release lines in parallel, and nearly every patch lands on the agent builder.
AWeber
AWeber keeps moving email marketing out of its own console and into whatever tool you already have open.
See all Buttondown alternatives → · See all Sulu alternatives →
Recent activity from Buttondown and Sulu
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoButtondownEvents API documented: pull deliveries, opens and clicks
- 2d agoButtondownMulti-select signup fields and self-syncing Bluesky cards
- 3d agoButtondownSilent automation skips fixed; re-adding unsubscribers keeps them pending
- 6d agoButtondownFaster draft sends; Word paste no longer locks the editor
- 7d agoButtondownBlank line above a table can be deleted
- 9d agoButtondownFont picker becomes a searchable specimen panel
- 1mo agoSuluSulu 3.0.8 validates selection filter params at build time
- 1mo agoSuluSulu 2.6.25 adds a redirect after SSO login
- 2mo agoSuluSulu 3.0.7 fixes smart-content filtering and speeds up indexing
- 2mo agoSuluSulu 2.6.24 upgrades CKEditor to version 48
- 3mo agoSuluSulu 3.0.6 migrates tag names to IDs with Doctrine migrations
- 3mo agoSuluSulu 2.6.23 moves to CKEditor 47 LTS and preps Symfony 8
Frequently asked questions
What is the difference between Buttondown and Sulu?
They serve adjacent needs but don't currently overlap on shipped themes. Buttondown and Sulu are shipping at a similar cadence (velocity 5.0 vs 5.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Buttondown better than Sulu?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Buttondown and Sulu are shipping at a similar cadence (velocity 5.0 vs 5.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Mkt Auto products to evaluate alongside.
What are the best alternatives to Buttondown?
Top Buttondown alternatives in Mkt Auto are ranked by recent ship velocity. Browse the "Buttondown alternatives" section above for the current picks, or visit /alternatives/buttondown 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.