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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

FeatureButtondownSulu
SectorMkt AutoMkt Auto
Velocity score5.05.0
Sparks · 30d00
Top themesnewsletters, account security, api permissions, accessibilityai disclosure, media provenance, two-factor auth, api deprecations
Last editorial update3d ago2mo ago
WebsiteVisit →Visit →

What is Buttondown?

Buttondown closes an API send loophole and blocks confirmation-email floods in its daily fixes.

Buttondown is a newsletter platform run on a daily-changelog cadence of small fixes. Over the last week it added sign-in limits, two-factor lockouts and auto-disabled failing webhooks, then closed a gap where API keys without sending access could still send through POST /v1/emails. It also stopped bots from signing one inbox up to many newsletters at once, and raised text contrast in light and dark mode.

Read the full Buttondown trajectory →

What is Sulu?

Sulu adds AI disclosure fields to media, shipped to both supported lines the same minute

Sulu is a Symfony-based CMS for developer-built sites, released as a synchronised pair: every 3.0.x patch ships within a minute or two of the matching 2.6.x patch, carrying largely the same pull requests. The 3.0.9 / 2.6.26 pair is the most substantive in months. Media assets gain Origin and AI Disclosure information, delivered as a doctrine migration with new columns and an updated form metadata snapshot, and the AI platform integration now reports a reason when it turns a request down. Two-factor setup adds an authenticator app (TOTP) flow and a Google Authenticator method, and a deprecation batch retires AbstractRestController, RestControllerTrait, ApiWrapper and the persistence component repositories and traits.

Read the full Sulu trajectory →

Buttondown vs Sulu: editorial side-by-side

B
Buttondown
MKT AUTO
5.0

Buttondown closes an API send loophole and blocks confirmation-email floods in its daily fixes.

◆ Current state

Buttondown is a newsletter platform run on a daily-changelog cadence of small fixes. Over the last week it added sign-in limits, two-factor lockouts and auto-disabled failing webhooks, then closed a gap where API keys without sending access could still send through POST /v1/emails. It also stopped bots from signing one inbox up to many newsletters at once, and raised text contrast in light and dark mode.

◆ Where it's heading

The daily polish is running on two tracks: account and API security (rate limits, 2FA lockout, API key permissions, abuse protection) and accessibility (screen-reader support, keyboard navigation, now contrast). Both point at a product being hardened for larger and more compliance-sensitive senders, not at new features.

◆ Prediction

Expect more permission and abuse fixes alongside further accessibility passes, still shipped as daily batches of small fixes.

S
Sulu
MKT AUTO
5.0

Sulu adds AI disclosure fields to media, shipped to both supported lines the same minute

◆ Current state

Sulu is a Symfony-based CMS for developer-built sites, released as a synchronised pair: every 3.0.x patch ships within a minute or two of the matching 2.6.x patch, carrying largely the same pull requests. The 3.0.9 / 2.6.26 pair is the most substantive in months. Media assets gain Origin and AI Disclosure information, delivered as a doctrine migration with new columns and an updated form metadata snapshot, and the AI platform integration now reports a reason when it turns a request down. Two-factor setup adds an authenticator app (TOTP) flow and a Google Authenticator method, and a deprecation batch retires AbstractRestController, RestControllerTrait, ApiWrapper and the persistence component repositories and traits.

◆ Where it's heading

Three threads run through the pairs and their balance has shifted. Editor and framework upkeep continue — Symfony 8 request bag replacements, PHPStan baselines kept green — but this release adds two things that aren't maintenance. The media provenance work puts AI disclosure into the content model itself rather than leaving it to editors, which is the shape of a CMS preparing for disclosure obligations. The controller and repository deprecations point the other way, at an API layer being cleared out ahead of whatever 3.x becomes, since 3.0 has otherwise read like a maintenance branch alongside 2.6.

◆ Prediction

Expect the deprecated REST controller and persistence layers to be removed in a future major, since deprecating four API surfaces in one release is how Sulu signals a rewrite is staged. Whether the AI disclosure fields are surfaced on the delivery side or stay editorial metadata isn't visible in these entries.

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.

See all Buttondown alternatives → · See all Sulu alternatives →

Recent activity from Buttondown and Sulu

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

  1. 3d agoButtondownHigher-contrast text, badges and links in light and dark mode
  2. 4d agoButtondownBlocks bots flooding an inbox with confirmation emails
  3. 5d agoButtondownAPI keys without send access can no longer send via POST /v1/emails
  4. 6d agoButtondownSign-in rate limits, 2FA lockout, auto-disabled failing webhooks
  5. 7d agoButtondownKeyboard navigation for lists; LGPD clauses added to DPA
  6. 8d agoButtondownFixes link colors, DNS checks and editor typing lag
  7. 2mo agoSuluMedia gains AI disclosure and origin fields; TOTP 2FA lands
  8. 2mo agoSulu2.6.26 mirrors 3.0.9 with AI disclosure and TOTP setup
  9. 3mo agoSuluSulu 3.0.8 validates selection filter params at build time
  10. 3mo agoSuluSulu 2.6.25 adds a redirect after SSO login
  11. 5mo agoSuluSulu 3.0.7 fixes smart-content filtering and speeds up indexing
  12. 5mo agoSuluSulu 2.6.24 upgrades CKEditor to version 48

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.