Buy Box lost and won, hijackers, suppressed listings, content and FBA fee changes. SentryKit sends each one the moment it happens, not on a 4-hour check. Buy Box alerts are included from $19/mo, and you pay per storefront, not per ASIN. Selling in Germany, Spain or anywhere in Europe? Alerts come in your language, with prices in your currency.
The six differences that decide the switch.
| Capability | SellerSonar | SentryKit |
|---|---|---|
| How fast alerts arrive | Every 4 hours on Pro, every 2 hours on Premium, hourly on Business and Enterprise. | Real-time on every plan. |
| Buy Box lost and won alerts | Not on Pro ($19.98/mo). You need Premium, from $39.98/mo. | Included on Starter, $19/mo. |
| What you pay for | ASIN and keyword caps: 150 ASINs on Pro, 300 on Premium, 500 on Business. | Storefronts. No ASIN or order caps, every marketplace included. |
| More than one Seller Central account | +$14/mo per extra account on Pro, Premium and Business. | 2 storefronts on Starter, 5 on Pro, then from +$19 each. |
| REST API and webhooks | Webhooks from Business ($74.98/mo). API on Enterprise only. | Included on every plan. |
| Free trial | 14 days. Full access costs $5; the free tier covers 5 ASINs and 10 keywords. | 14 days, full access, no credit card. |
SellerSonar prices are annual billing, from sellersonar.com/pricing, checked 4 October 2026.
Running client accounts? See how agencies use SentryKit →
Every alert carries the numbers you need to decide what to do next. Two examples, with sample data.
SellerSonar plans cap your ASINs and keywords: 150 ASINs on Pro, 500 on Business. SentryKit is priced on the storefronts you connect, so one plan covers your whole catalog in every marketplace, whether you list 200 ASINs or 20,000.
A Q4 spike or a flash sale never triggers an overage or a cutoff. Pricing follows your storefronts, not how many orders you process.
SellerSonar annual prices, from sellersonar.com/pricing, checked 4 October 2026: Pro $19.98/mo (150 ASINs, every 4 hours, no Buy Box lost/won) · Premium $39.98/mo (300 ASINs, every 2 hours) · Business $74.98/mo (500 ASINs, hourly) · Enterprise custom. Monthly billing is $23.98, $47.98 and $89.98.
Sellers shopping for a SellerSonar alternative usually evaluate one or two adjacent monitoring tools and a suite's alerts module before deciding.
Real-time alerts · No credit card · Cancel anytime
If you want to know the moment something changes, SentryKit is built for that. It sends real-time alerts for Buy Box lost and won, hijackers, suppressed listings, content and FBA fee changes on every plan, from $19/mo. SellerSonar's entry plan checks every 4 hours and leaves Buy Box lost/won alerts out until Premium.
SellerSonar's update frequency depends on the plan: every 4 hours on Pro, every 2 hours on Premium, and hourly on Business and Enterprise. SentryKit sends alerts in real time on every plan, including the $19 Starter plan.
SellerSonar prices by ASIN and keyword count: Pro $19.98/mo, Premium $39.98/mo and Business $74.98/mo on annual billing, with Enterprise on request. SentryKit prices by storefront: Starter is $19/mo for 2 storefronts and Pro is $49/mo for 5, with no ASIN or order caps. Buy Box lost and won alerts, the REST API and webhooks are included on both plans.
Yes. SentryKit covers Amazon.de, Amazon.es, Amazon.fr, Amazon.it, Amazon.co.uk and more on every plan. Alerts arrive in your own language, and every price shows in the marketplace's currency, so a seller on Amazon.de or Amazon.es sees alerts in German or Spanish with prices in EUR.
Start the 14-day free trial, no credit card needed. Connect your Seller Central account and alerts start across your whole catalog. You can run both tools side by side during the trial and compare the alerts on real events, then pick Starter or Pro based on how many storefronts you run.
Yes. Connect every client account in one workspace and send each brand's alerts to the account manager who owns it. Pro includes 5 storefronts, then from +$19 each. SellerSonar charges +$14/mo for each extra account on Pro, Premium and Business.
