Plays nice with your stack.
Production-safe at Plus volume.
Spar reads from GA4 and Clarity, routes through GrowthBook or Intelligems, and ships through Shopify's theme app extensions. We don't ask to replace anything. We slot in.
Want to kick the tires first? Start a 14-day free trial on one of your stores.
Three questions every Plus team asks before saying yes.
Here is how Spar answers each one.
One bad variant on a high-traffic day is real money.
When the store does six figures an hour, a checkout-breaking test isn't a learning. It's a refund queue. Most growth tools don't acknowledge this. They ship theme rewrites, set traffic to 50/50, and call it a day.
Procurement always asks the questions.
Every new vendor is a six-week tour through security review, data residency, DPA, vendor risk. A growth tool that can't answer the questions doesn't get added. It gets dropped from the shortlist.
Your stack already tests.
You pay for GrowthBook or Intelligems or Convert. You have GA4, Clarity, Klaviyo. The question isn't whether you need another platform. It's whether anything new earns the integration cost. Spar does.
Spar connects your stack rather than replacing it.
Spar reads the data you already collect, ships through the test platforms you already use, and lands on Shopify through the surfaces Shopify already supports.
GA4
events, funnels, anomalies
Klaviyo
audience exports both directions
Microsoft Clarity
session recordings, heatmap signals
GrowthBook
routes test exposures
audience signals and ads conversions
Judge.me
reviews, voice-of-customer signals
Shopify
catalog in, variants via theme app extension and app proxy
Intelligems / Convert
routes test exposures
Spar
Reads, decides, routes, ships.
Warehouse sync coming soon. Integration availability current as of June 2026. Full list on the integrations page.
What we actually do, and how we promise to do it.
Four capabilities, each engineered to clear procurement on the first call.
Production-safe variants
Variants are scoped JavaScript rather than theme rewrites. Rollback is one screen. You can cap exposure, exclude high-cart users, and stop a test from the same place you started it. Bad variants are always possible. The blast radius is not.
Procurement-ready posture
DPA on request. Encryption in transit and at rest. A public security page that walks your vendor-review team through how we handle data, access, and incident response, in the level of detail their checklist expects.
Founders in Slack, 90 days
Not a CSM. Not a queued ticket. The founders are in your Slack while you ramp, answering architecture questions in hours and shipping the integration fixes you ask for. You know who is on the other end of every message.
Slots into your test stack
If you already test with GrowthBook, Spar routes exposures through it. Same for Intelligems and Convert when you have one. We do not insist you adopt our experiment engine to use the rest of the platform.
Spar for other kinds of team
Each one says, plainly, what Spar does for that shape of work and which plan it lands on.
Founders
One store, no growth team, lots of leverage on $500.
In-house ecommerce
Lean DTC team. Spar carries the audit, idea, and mockup load.
Agencies
Multiple clients in one workspace. Per-store math we work out on the call.
SaaS teams
Pro for small teams, Enterprise once SSO and a custom credit pool matter.
The growth tool your security team won't reject.
Talk to the people building Spar. We'll cover the integration map, the security posture, and the rollback story. No SDR, no script.