Stacks - 2026 Pricing, Features, Reviews & Alternatives

Stacks is a cloud-based all-in-one business platform that consolidates seven tools — CRM, email marketing, review management, invoicing, scheduling, support desk, and tasks and time tracking — into a single web-based environment accessed via a custom subdomain. All modules operate on one shared contact record, one unified inbox, and one login, eliminating data silos across business functions. The core platform is free forever with unlimited users and no per-user fees, making it viable for solo operators and teams scaling up to 300 members without incremental subscription costs.

Stacks supports contact CSV import and connects to third-party email sending providers including Brevo, Resend, and SendGrid. An automation builder is included across all plans. The Sales CRM covers pipeline, deal, and contact management; Email Marketing handles campaigns and sequences; the Invoicing module supports estimates, invoices, and payment collection via a connected Stripe account; Scheduling manages bookings and availability; the Support Desk handles tickets and a help center; and Tasks and Time covers to-dos and time tracking. Review management enables reputation monitoring and review collection. Because all seven modules share a single contact record, a lead's complete history — emails, payments, appointments, and support tickets — is accessible from any module without switching tools or re-entering data.

An optional AI Pro tier extends AI functionality beyond the 50 one-time shared credits available on the free plan. Supported AI capabilities include drafting emails and follow-ups, scoring and prioritizing leads, drafting replies to customer reviews, reading invoices and receipts from photos and converting them to records, and answering questions about business data. The AI Pro tier also removes platform branding from customer-facing pages and adds priority support. Stacks carries no ads and does not sell user data, positioning it as a cost-consolidation alternative to maintaining separate subscriptions across tools such as a dedicated CRM, email platform, scheduling tool, invoicing service, and support desk.