# Fillout vs Formstack (slim)

> Fillout scores 52.2 (D) on agent readiness against Formstack's 49 (D), and leads in 4 of 7 scored categories. Formstack leads on schema & documentation, agent ergonomics and security & auth. Both do forms responses. Category scores, facts, verdicts and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/fillout-vs-formstack.md (~2,250 tokens) · this version ~730 tokens · JSON https://www.anchorterminal.com/compare/fillout-vs-formstack.json · canonical https://www.anchorterminal.com/compare/fillout-vs-formstack
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-08

Fillout scores 52.2 (D) on agent readiness against Formstack's 49 (D), and leads in 4 of 7 scored categories. Formstack leads on schema & documentation, agent ergonomics and security & auth. Both do forms responses.

- Fillout: D 52.2, rank #567 of 722 · https://www.anchorterminal.com/tools/fillout.min.md
- Formstack: D 49, rank #616 of 722 · https://www.anchorterminal.com/tools/formstack.min.md
- Fillout, good for An agent that reads form responses, files submissions on a person's behalf or subscribes a webhook to a form someone has already built. Ahead on Reliability, 70 against 63; Payments & pricing, 30 against 15; Maintenance & community, 46 against 20; Transparency & trust, 69 against 64.
- Formstack, good for An organisation that already runs Formstack Forms, has bought the API add-on and wants an agent to build forms, read or search submissions and manage signed webhooks, including HIPAA and PCI use. Ahead on Schema & documentation, 69 against 63; Agent ergonomics, 52 against 47; Security & auth, 43 against 37.

| Category | Fillout | Formstack |
| --- | --- | --- |
| Reliability (16%) | 70 | 63 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 63 | 69 |
| Agent ergonomics (13%) | 47 | 52 |
| Security & auth (14%) | 37 | 43 |
| Payments & pricing (10%) | 30 | 15 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 46 | 20 |
| Transparency & trust (7%) | 69 | 64 |

| Fact (where they differ) | Fillout | Formstack |
| --- | --- | --- |
| Vendor | Restly, Inc. (trading as Zite) | Intellistack, LLC |
| Hosted endpoint | `https://api.fillout.com/v1/api` | `https://www.formstack.com/api/v2025` |
| Auth | OAuth or key | Token |
| Pricing | Freemium | Paid |
| Price for forms responses | $15 per month (plan) | not published |
| Licence | Proprietary service under Fillout's terms of service. The TypeScript API client on GitHub is MIT | Proprietary service under the Intellistack Software Services Agreement. No vendor SDK or open-source client was found |
| Last release | none | 2026-06-18 |
| Terms last updated | 2022-07-02 | couldn't be read |
| Privacy policy last updated | 2025-10-07 | couldn't be read |
| Customer content may train models | not found in the text | couldn't be read |
| Terms restrict automated access | not found in the text | couldn't be read |
| Terms restrict benchmarking | yes | couldn't be read |
| Terms or service can change without notice | yes | couldn't be read |
| Arbitration or class-action waiver | yes | couldn't be read |
| Popularity | 1.8k npm/wk | none |