Subsecond — Autonomous Shopify
Mobile Speed Engine.
Cut mobile load times under 1.5s, defer bloated scripts, and eliminate lost ad spend.
$199/mo after trial. Cancel anytime. No live theme risk, ever.
<1.5s
Target mobile LCP
0
Live theme mutations without approval
14 days
Free trial, full teardown included
The product
One agent. One job. Done safely.
Subsecond doesn't touch your live storefront — it stages a complete speed refactor in a draft theme, and only ships once you approve it.
Sub-1.5s mobile LCP
Subsecond refactors critical CSS, image pipelines, and script order until your largest contentful paint lands under 1.5 seconds on real mobile networks.
WebP/AVIF conversion, automatically
Every oversized hero, banner, and product image is converted to a responsive WebP/AVIF srcset — no manual re-uploading, no theme knowledge required.
Render-blocking scripts, deferred
Klaviyo, Yotpo, TikTok pixels, and other app-embed scripts are analyzed and deferred so they stop blocking your first paint.
Draft-theme only, always
Every refactor is staged in an unpublished draft theme. Nothing ships to your live storefront without your explicit approval.
How it works
From free teardown to live speed, in three steps.
Free teardown
Drop in your domain. Subsecond runs a real mobile PageSpeed audit and shows you exactly what's costing you conversions.
1-click Shopify OAuth
Connect your store in one click. We request draft-theme-only scopes — never write access to your live theme.
Draft refactor + human approval
Subsecond stages the full speed refactor in a draft theme. You review the before/after, then approve with a 4-digit PIN to go live.
Client safety firewall
Your live store is never at risk.
Every agent in the unthrottle.ai fleet is built against the same human-in-the-loop firewall. Nothing mutates your live theme, prices, or ad budgets without a founder-approved PIN.
- ✓Zero live theme mutations — all refactors staged in unpublished drafts
- ✓Founder PIN gate required before anything reaches your live storefront
- ✓One daily briefing at 08:30, zero noisy intra-day pings unless it's P0
- ✓Hard-capped LLM & API spend — never a surprise infrastructure bill
Simple pricing
$199/month
One store. Unlimited draft refactors. Weekly ROI proof cards.
No setup fees. No credit card risk to your live theme, ever.