Stack AI vs Fillout
A detailed comparison to help you choose between Stack AI and Fillout.
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Verdict: Fillout wins
Fillout scores 4.1/5, edging out Stack AI at 3.5/5. Small-to-mid teams that want Typeform-grade form design with far cheaper scaling and native two-way sync into Airtable, Notion or Salesforce.
Stack AI Build AI workflows and apps without code | Fillout Build forms and surveys without code in minutes | |
|---|---|---|
| Rating | 3.5 (1 review) | 4.1 (1 review) |
| Pricing Model | freemium | freemium |
| Starting Price | Free tier available | Free tier available |
| Best For | Enterprise and IT-led teams building secure internal AI tools and document workflows — particularly those already using Asana — who can run a pilot and negotiate a custom contract. | Small-to-mid teams that want Typeform-grade form design with far cheaper scaling and native two-way sync into Airtable, Notion or Salesforce. |
| Free Tier | ||
| API Access | ||
| Team Features | ||
| Open Source | ||
| Tags | free tierno codesso | free tierno codeapi access |
| Visit Stack AI → | Visit Fillout → |
Stack AI
Pros
- + Model-agnostic node canvas: any LLM behind the graph, with structured JSON outputs validated in-flow in my build
- + Document AI with working citations — outputs pointed at the right source PDFs in my spot checks
- + Enterprise compliance posture: Trust Center, HIPAA BAA path, on-prem deployment and dedicated infrastructure on Custom
- + Genuinely free entry point at 500 runs/month with no card, plus live docs, Academy, changelog and public status page
- + Acquired by Asana (May 2026) — potential distribution and workflow integration upside for teams already in that ecosystem
Cons
- - Acquired by Asana for a reported $75M in May 2026 — roadmap and pricing stability need contractual clarity before multi-year deals
- - No self-serve paid tier: 500 runs/2 projects on Free, then custom-negotiated pricing with nothing published in between
- - Third-party pricing roundups disagree wildly ($49–$199/mo) and are not vendor-confirmed — do not budget from aggregators
- - Denser, less polished UI than consumer-grade builders; overbuilt for simple FAQ-style use cases
- - Free tier (500 runs) is about one serious build-and-debug session — too tight for a real evaluation month
Fillout
Pros
- + Free plan collects 1,000 responses/month with unlimited forms, questions and seats — verified against Typeform's 10/month free cap
- + No per-seat charges on any tier, so billing tracks usage instead of headcount
- + Bidirectional Airtable/Notion mapping with URL-parameter pre-fill and conditional display — form-as-front-end for internal systems
- + Deep free-tier feature set: conditional logic, payments, scheduling, PDF generation, workflows and resume-in-progress submissions
- + Pricing matrix is published server-side with concrete limits (20 MB vs 1 GB file ceilings) rather than hidden behind sales calls
Cons
- - Custom domains require the $75/month Business tier (annual billing) even for teams that need little else
- - Response caps (1,000/2,000/5,000) push you up tiers fast if a form catches traffic; only Business is uncapped
- - Partial submissions — recovery of abandoned entries — are gated to Business, where small teams need them most
- - Address autocomplete, enrichment and SMS/email verification are paid add-ons on top of plan prices
- - Hosted only: no self-hosting or on-prem option for teams with data-residency constraints
Frequently Asked Questions
Which is better, Stack AI or Fillout?▼
Fillout scores higher at 4.1/5 vs 3.5/5 for Stack AI, making it the better-rated option in our comparison.
What is the difference between Stack AI and Fillout?▼
Stack AI: Stack AI is a drag-and-drop platform for building AI agents and internal applications, aimed at enterprise deployment and compliance. Fillout: Fillout builds forms, surveys and quizzes without code and writes responses into tools such as Airtable, Notion and Salesforce.
Is Stack AI or Fillout more affordable?▼
Stack AI starts at €0/mo, Fillout starts at €0/mo. Check the comparison table above for current pricing.
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