Stack AI vs Relevance AI (2026): Build the Tool, or Hire the Workforce?

The verdict in one line: Both build no-code AI agents, but they sell different dreams. Stack AI hands you a visual workshop to build internal LLM tools with enterprise-grade security. Relevance AI hands you an "AI workforce" — a team of digital staff that pass jobs between each other. For the typical Australian buyer, Relevance AI wins: it scored 20/25 to Stack AI's 16/25, and it is the only one of the two that hosts your data in Sydney.

The tension: a workshop, or a workforce?

These two tools sit in the same category and solve the same broad problem — automating recurring work with AI agents. But they frame that problem in opposite ways, and the framing tells you who each one is for.

Stack AI sells you a builder. You drag nodes onto a canvas, wire them together, and ship an internal LLM tool. The mental model is engineering: you are constructing software. Stack AI's strength is what sits underneath that builder — SOC 2 Type II, ISO 27001, HIPAA, on-premise deployment. It is a workshop built for an IT department.

Relevance AI sells you staff. Its headline feature is "Workforce" — a manager agent that delegates to specialist agents, each with a role, escalating to a human when needed. The mental model is hiring: you are assembling a team of digital workers. You describe the job in plain English and the platform drafts the agent for you.

One asks "what tool do you want to build?" The other asks "what worker do you want to hire?" That difference runs through everything below — and for an Australian buyer, it lands hardest on price and data residency.

We have reviewed both in full. This piece compares them head-to-head; it does not re-score them.

What they cost in Australia (AUD + GST)

Here is the catch that applies to both: neither prices in Australian dollars. Both bill in USD with no AUD toggle, so every figure carries currency risk. We convert at US$1 ≈ A$1.40 and show the GST-inclusive landed cost, because international digital services bought for business use generally fall under Australia's GST rules.

The single most important row is the empty one. Stack AI publishes no mid-tier paid plan — confirmed on its pricing page as at 28 June 2026. You get a capped free tier or a "call sales" Enterprise quote, and nothing in between. A Melbourne small business that outgrows 500 runs a month has no card-swipe upgrade path. That is a structural gap, not an oversight: Stack AI is built for procurement, not self-serve.

Relevance AI gives you a real ladder — Pro at about A$27 a month, Team at about A$328 a month, then Enterprise. You can start small and grow without a sales call. The Free plan that used to sit below Pro was retired and closed to new signups in September 2026 (verified 23 Sep 2026), so the ladder now starts at Pro; Stack AI's free tier is currently the only no-cost way into either.

But Relevance AI's meter carries its own warning. Since a September 2025 overhaul, it splits billing into Actions (each tool run) and Vendor Credits (the underlying model cost, passed through at no markup). The Pro plan's 30,000 actions a year is roughly 82 a day — and a single busy agent can burn that in an afternoon. Top-ups run about US$40 per 1,000 extra Actions. The bill is honest, but it is hard to forecast.

The honest GST line, for both: neither vendor bills in AUD or against an ABN on its public plans, so we cannot confirm exact GST handling at checkout from a primary invoice. Treatment depends on whether you are registered and have supplied your ABN. Confirm the FX and GST with your accountant before you commit either way.

Feature diff: where they actually differ

On the surface both do the same things — no-code builder, LLM-agnostic, integrations, human-in-the-loop checkpoints. The differences are in emphasis.

Read that table and the split is clear.

Stack AI is deeper on deployment and compliance. Four deployment models including fully air-gapped on-premise, plus ISO 27001 and HIPAA, make it the stronger pick for a buyer whose security team has hard, audited requirements. Our review scored its Feature Depth 4/5 and Reliability & Support 4/5 on the strength of that stack.

Relevance AI is deeper on the agent model itself. Its Workforce layer — agents delegating to agents — is one of the more mature multi-agent implementations available, and "Invent" lowers the on-ramp for a non-technical operator more convincingly than Stack AI's bare canvas. Our review scored its Feature Depth a full 5/5, best-in-class.

So: Stack AI wins the compliance checklist; Relevance AI wins the actual job of building and running agents. For most Australian buyers, the second matters more — unless you are in a regulated industry where the first is a gate you cannot pass.

Australian fit: the deciding ground

This is where the two part company hardest, and it is the criterion this publication weighs most heavily.

Origin. Stack AI is a US company — MIT-founded, Y Combinator-bred, and as of 28 May 2026 owned by Asana, which paid US$75 million and is folding the product into its own platform. Relevance AI was founded in Sydney in 2020 and is still Sydney-headquartered, backed in part by Australian investors. In a category dominated by US names, that homegrown story is rare.

Data residency — the decider. Relevance AI lets you choose your hosting region at signup: AU (Sydney), US or EU, locked once chosen. For a business that needs customer data to stay onshore, that is a serious advantage almost no global rival matches. Stack AI publishes no Australian hosting region for its standard product; its docs note you can choose an AWS region for data-residency needs, but no specific Australian region is confirmed as default or available. The only safe onshore route on Stack AI today is the on-premise/VPC option — which means an Enterprise sales process, not a signup.

AUD billing. A wash, and a disappointing one. Neither offers native AUD billing. Both quote and charge in US dollars. For a Sydney-built company, Relevance AI's USD-only billing is its single biggest local-fit miss — but it is the same miss Stack AI makes, so it does not separate them.

GST. Identical treatment for both: US-billed SaaS, GST handling dependent on your registration and ABN, not confirmable from a primary invoice. Neither has an edge here.

Support. Relevance AI's Sydney head office implies AEST-hours support — a quiet advantage over a US tool that answers at 3am Australian time — though a dedicated AU SLA is not confirmed from a primary source. Stack AI's free tier is Discord-only; dedicated support is an Enterprise feature, with no confirmed Australian-hours SLA.

The scores reflect the gap. Stack AI scored Australian Fit 2/5 — US company, USD-only, no published onshore region, community-only free support. Relevance AI scored Australian Fit 4/5 — Sydney-built, Sydney data residency, SOC 2 Type II, docked only for USD billing. That two-point swing is the whole ballgame.

It also has a hard consequence under our scoring gate. Stack AI's 2/5 Australian Fit means that — regardless of its raw total — it cannot be a five-star tool and cannot be named a category Top Pick. Relevance AI's 4/5 clears that gate. To be excellent for Australians, a tool has to be excellent for Australians.

The scoreboard

Neither of these is re-scored here; both numbers come straight from our full reviews.

Both land in the four-star band. But Relevance AI sits four points clear, wins three of the five criteria outright, ties two, and loses none. Stack AI does not beat it on a single line.

Who buys which

Buy Relevance AI if you are a typical Australian operator. A consultant, an agency, a property manager, a mid-market team with a repeatable, high-volume job to automate — lead qualification, inbound triage, research-and-draft pipelines. You get a real pricing ladder starting at about A$27 a month, the strongest multi-agent model in the category, plain-English agent creation, and — the clincher — the option to keep your data in Sydney. Start on Pro, scope one workflow tightly, and watch the Actions meter.

Buy Stack AI only in a narrow case: you are an enterprise or regulated buyer — finance, healthcare, legal — with an IT function, a procurement process, and a security team that demands ISO 27001, HIPAA, or fully air-gapped on-premise deployment. There, Stack AI's compliance stack and four deployment models earn their keep, and the lack of a self-serve plan is irrelevant because you were always going to negotiate a contract. Even then, nail down an Australian data region in writing before you sign, and factor in the open question of where Asana takes the product next.

For everyone in between — the curious small business owner, the solo operator dipping a toe in — neither is a casual purchase. Both demand process-design thinking that "no-code" undersells. But if you are going to invest that effort, invest it in the tool that hosts your data onshore and lets you pay by the month.

The winner

For the typical Australian buyer, Relevance AI is the clear winner. It outscores Stack AI 20 to 16, it is the only one of the two built and hosted in Australia, and its "hire a workforce" model fits the operator who wants recurring jobs done — not an engineering team building internal tooling.

Stack AI is a genuinely strong piece of engineering with a best-in-class compliance stack. But it is built for a US enterprise procurement process, and it shows. For the 35-year-old Melbourne business owner this publication is written for, Relevance AI is the one to shortlist first.

Frequently asked questions

What's the real difference between Stack AI and Relevance AI?

Framing. Stack AI gives you a visual builder to construct internal LLM tools, with heavy enterprise security underneath. Relevance AI gives you an "AI workforce" — a team of agents that delegate jobs to each other. Same category, different mental model: build a tool versus hire a worker.

Which is better for an Australian small business?

Relevance AI. It has a priced ladder starting at about A$27/mo, while Stack AI publishes only a free tier and a "call sales" Enterprise quote with nothing in between. Relevance AI also lets you host data in Sydney.

Do either of them charge in Australian dollars?

No. Both bill in US dollars with no AUD toggle, so both carry currency risk. We convert at US$1 ≈ A$1.40. Confirm GST treatment with your accountant, as it depends on your registration and ABN.

Which one keeps my data in Australia?

Relevance AI — you choose AU (Sydney) hosting at signup, locked once chosen. Stack AI publishes no Australian region for its standard product; the only onshore route is its on-premise/VPC option on Enterprise.

What did each score in your reviews?

Relevance AI scored 20/25 (Very Good) and Stack AI scored 16/25 (Very Good). Stack AI's weak Australian Fit (2/5) also caps it below five stars and bars it from being a category Top Pick under our scoring gate.

Read next

• Our methodology — how we score
• Stack AI review (2026)
• Relevance AI review (2026)
• Relevance AI vs Lindy
• The best AI automation tools in Australia (2026 roundup)

Sources

Primary sources, checked 28 June 2026.

• Stack AI — Pricing (Free / Enterprise only; 500 runs/mo; no mid-tier): https://www.stackai.com/pricing (live-fetched 28 June 2026; today's Wayback capture queued — the save endpoint was rate-limiting at time of writing, and no prior snapshot of this URL exists)
• Stack AI — Security (SOC 2 Type II, ISO 27001, HIPAA, GDPR): https://www.stackai.com/security — Wayback 10 July 2026
• Relevance AI — Pricing (Free / Pro / Team / Enterprise; Actions + Vendor Credits): https://relevanceai.com/pricing (live page renders the Enterprise tier alone; Pro/Team figures cross-checked below. Latest Wayback snapshot 16 June 2026: https://web.archive.org/web/20260616073133/https://relevanceai.com/pricing — today's recapture queued)
• Relevance AI — Pricing & packaging docs (Actions vs Vendor Credits, top-up rates): https://relevanceai.com/docs/admin/subscriptions/new-pricing — Wayback 6 May 2026
• Relevance AI — Security & data residency, AU (Sydney) / US / EU region choice: https://relevanceai.com/docs/admin/security — Wayback 6 June 2026
• Asana — Press release: "Asana Acquires StackAI" (28 May 2026): https://asana.com/press/releases/pr/asana-acquires-stackai-adding-cross-system-execution-for-human-agent-teams/e7c73b97-ae8c-4e51-b927-189ccb184146 — Wayback 14 June 2026

Secondary (Relevance AI Pro/Team plan figures cross-check, used because the live pricing page rendered the Enterprise tier alone at time of fetch): - Lindy — Relevance AI pricing breakdown: https://www.lindy.ai/blog/relevance-ai-pricing — Wayback 16 February 2026

Scores and verdicts are carried verbatim from our full reviews and were not re-derived for this comparison: - Stack AI review (16/25): /stack-ai-australia-2026 - Relevance AI review (20/25): /review-relevance-ai-australia-2026

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