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Fillout vs Formstack

Fillout scores higher on the AgentReady, 56/100 against 37/100. They differ on 10 of the 41 signals. Which ones decides whether an agent can adopt them without a person watching.

What each one is

Fillout. Fillout is an all-in-one form solution for creating forms, quizzes, and surveys.

Formstack. Formstack is a platform for creating forms, documents, and eSignatures that are designed to work together.

Where Fillout is ahead

Fillout passes clear product positioning, public docs discoverable and package / cli discoverable, and Formstack does not. That is discover, whether an agent can find the product at all without being told it exists.

It also holds adopt: no mandatory sales call, agent-compatible signup flow, fast time to first request, copyable quickstart and official typescript sdk. Formstack misses those.

And on operate, structured, predictable output. Formstack misses it.

Where Formstack is ahead

Formstack passes llms-full.txt / full agent docs, and Fillout does not. That is discover, whether an agent can find the product at all without being told it exists.

What neither does

Both fail mcp discoverable, openapi / spec quality, authentication documented, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented, programmatic credential creation, official python sdk, cli available, mcp integration available, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified. If your agent needs any of those, you will be building it yourself either way.

Score, pillar by pillar

The AgentReady splits into four pillars, scored separately, because a product can be easy to find and still impossible to adopt.

Discover. Fillout leads 80 to 53. Fillout misses llms-full.txt / full agent docs, mcp discoverable; Formstack misses clear product positioning, public docs discoverable, mcp discoverable, package / cli discoverable.

Understand. Both sit at 38/100 here. Fillout misses openapi / spec quality, authentication documented, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented; Formstack misses openapi / spec quality, authentication documented, request examples provided, response examples provided, errors and status codes documented, limits / constraints documented.

Adopt is whether an agent can get a key and make its first successful call without a human in the loop. Fillout leads 60 to 20. Fillout misses programmatic credential creation, official python sdk, cli available, mcp integration available; Formstack misses no mandatory sales call, agent-compatible signup flow, programmatic credential creation, fast time to first request, copyable quickstart, official typescript sdk, official python sdk, cli available, mcp integration available.

Operate. Fillout leads 47 to 35. Fillout misses machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified; Formstack misses structured, predictable output, machine-readable errors, retry behavior documented, idempotency support, rate-limit behavior predictable, agent compatibility verified.

Pricing

Fillout starts at $15/mo and has a free tier. Formstack starts at $83/mo with no free tier.

Signal by signal

Which to pick

Fillout clears more of the signals an agent needs, so it is the safer default for unattended use. Full profiles: Fillout and Formstack. Alternatives to each: Fillout, Formstack.

An agent can fetch this as data: POST /v1/compare {"slugs": ["fillout", "formstack"]}