Staxly

Loops vs GrowthBook

Email marketing for SaaS — loops, transactional, campaigns in one
vs. Open-source feature flags + experimentation — Warehouse Native

Loops websiteGrowthBook website

Pricing tiers

Loops

Free
1,000 subscribed contacts. 4,000 sends/month. All features. Loops footer on emails.
Free
Paid — 1.5k
1,500 contacts. Unlimited sends. No footer.
$15/mo
Paid — 5k
5,000 contacts. Unlimited sends.
$49/mo
Paid — 10k
10,000 contacts.
$99/mo
Paid — 25k
25,000 contacts.
$199/mo
Paid — 50k
50,000 contacts.
$349/mo
Custom
>100k contacts — contact sales.
Custom
Loops website

GrowthBook

Open Source (Self-Host)
MIT-licensed. Unlimited everything. Community support.
$0 base (usage-based)
Cloud — Starter (Free)
Up to 3 users. Unlimited flags + experiments. Warehouse Native included.
Free
Cloud — Pro
$40/user/month. Up to 50 users. Advanced stats, visual A/B editor, CUPED, sequential testing, bandits.
$40/mo
Cloud — Enterprise
Custom. Unlimited users, SSO/SAML, approval flows, data pipelines, exportable audit logs.
Custom
Self-Host Enterprise
Open Source + Enterprise license. Visual A/B editor, advanced metrics, SSO/SAML, approvals, training.
Custom
GrowthBook website

Free-tier quotas head-to-head

Comparing free on Loops vs oss on GrowthBook.

MetricLoopsGrowthBook
No overlapping quota metrics for these tiers.

Features

Loops · 12 features

  • API KeysScoped keys for testing vs production.
  • Audiences (Segments)Filter contacts by properties + event behavior.
  • Campaign AnalyticsOpen/click/unsubscribe rates, heatmaps, A/B significance.
  • CampaignsOne-off broadcasts to audience segments. Schedule + A/B test subject.
  • ContactsContact records with custom properties (strings, numbers, booleans, dates).
  • Email EditorVisual block-based + Markdown + HTML modes.
  • EventsSend events to trigger loops/journeys or filter audiences.
  • Loops (Automations)Event-triggered automation flows with delays + conditions.
  • Mailing ListsOpt-in lists with subscribe/unsubscribe preferences per list.
  • Template LibraryPre-built templates for SaaS use cases (onboarding, digest, launch).
  • Transactional APISend transactional emails (receipts, password resets) via /transactional endpoin
  • WebhooksSubscribe to contact/event changes.

GrowthBook · 15 features

  • Approval FlowsRequire reviewer approval on flag changes. Enterprise.
  • Audit LogsFull change history. Exportable on Enterprise.
  • Dimensions & SlicingBreak down experiment results by user dimensions.
  • Edge SDK SupportCloudflare Workers, Lambda@Edge, Fastly, Akamai EdgeWorkers, Netlify Edge.
  • ExperimentsA/B/n with CUPED variance reduction + sequential testing.
  • Feature FlagsBoolean + string + number + JSON flags with targeting.
  • Feature Reviews (PR-style)Draft → review → approve flag changes.
  • Guardrail MetricsAuto-monitor key metrics during experiments.
  • Metric CatalogDefine + reuse metrics across experiments.
  • Multi-Armed BanditsAdaptive traffic allocation. Pro+.
  • Safe RolloutsGuarded gradual rollouts with automatic rollback.
  • SSO / SAMLEnterprise SSO for cloud + self-host EE.
  • Sticky BucketingUser stays in variant even after eligibility changes.
  • Visual A/B Test EditorNo-code DOM editor for web experiments. Pro+.
  • Warehouse NativeConnect your warehouse + run experiments against your events data.

Developer interfaces

KindLoopsGrowthBook
SDK@loops/loops, loops-pyEdge SDKs (CF Workers / Lambda@Edge / Fastly / Akamai), growthbook-android, growthbook-flutter, growthbook-go, growthbook-java, growthbook-node, growthbook-php, growthbook-python, growthbook-ruby, growthbook-swift, sdk-javascript, sdk-react
RESTLoops REST APIGrowthBook REST API
OTHERWebhooksWebhooks
Staxly is an independent catalog of developer platforms. Outbound links to Loops and GrowthBook are plain references to their official websites. Pricing is verified against vendor pages at publication time — reconfirm before buying.

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