If you only need hosted API docs — not SDK generation — you don't need Stainless's per-generator pricing model at all. Docs-focused tools price and scale differently. As of September 2026, the closest fits are Mintlify (docs-first, generous free custom domain), ReadMe (full developer portal with metrics and changelog), Redocly (governance and API catalog at scale), and Sourced (docs generated straight from the same OpenAPI spec that also produces your SDK previews, free to try). Pick based on whether you need a portal, a catalog, or just clean docs plus SDKs later.
If Stainless's docs platform was on your shortlist, cross it off: as of September 2026 it isn't accepting new customers either. Per Stainless's own announcement, Stainless is joining Anthropic, and the company says it's winding down all hosted Stainless products — not just SDK generation — with new signups, projects, and SDKs stopped as of that post. WorkOS's coverage sums up the practical effect: the hosted SDK generator is going away. That leaves Mintlify, ReadMe, Redocly, and Sourced below as the live docs-only options; if you already have Stainless docs to move off of, see the migration guide.
Why "docs only" buyers hit friction with Stainless
Stainless prices around a "generator" unit — any single SDK, docs site, or MCP server counts against the same pool. On the free plan, that's up to 5 generators total and 5 seats, capped at 25 endpoints, with 100 preview builds a month and a 25/day rate limit (verified against stainless.com/pricing as of September 2026). If your docs site is one of those 5 generators, you're sharing quota with any SDKs or MCP servers you also spin up.
The free plan also excludes the things a docs-only buyer usually wants first: a custom domain, AI markdown rendering, custom JS/CSS, a full component library, password-protected docs, and removing the "powered by Stainless" mark. Those sit behind paid tiers. Stainless doesn't publish exact paid-tier pricing on its public page — plan names beyond Free appear but dollar amounts aren't shown in the static page content, so get a live quote before comparing costs directly.
If your actual need is "host our API reference well," that's a narrower job than what Stainless is built for, and a docs-first tool usually gets you further per dollar.
The docs-focused options
| Tool | Free tier | Custom domain on free | Best for |
|---|---|---|---|
| Mintlify | Starter, $0/mo, 5 editor seats | Yes | Docs-first teams that want AI features on a paid tier later |
| ReadMe | Starter, $0/mo | Yes | Full developer portal: metrics, changelog, forums, bi-directional sync |
| Redocly | No free hosted tier (Pro starts at $10/seat/mo) | N/A on Pro's base; custom domain is part of Reunite hosting | Governance, API catalogs, multi-API orgs |
| Sourced | Unlimited previews, up to 2 hosted noindex docs review sites and one hosted MCP server, no credit card | Custom domain ships with paid plans | Teams that want docs and typed SDKs generated from one OpenAPI spec |
(Verified against mintlify.com/pricing, readme.com/pricing, and redocly.com/pricing as of September 2026.)
Mintlify
Mintlify's free Starter tier includes the full platform, a custom domain, a web editor, authentication, an MCP server, and an API playground, with 5 editor seats. AI features (agent, assistant, automations) are Pro-only at $450/month with unlimited seats. If your docs are mostly static reference content and you don't need AI-assisted authoring yet, the free tier is a strong, no-nonsense starting point.
ReadMe
ReadMe's free Starter plan includes a custom domain, bi-directional sync, an interactive API reference, usage metrics, a markdown editor, customizable themes, and basic AI (AI dropdown, llms.txt, MCP server). Pro jumps to $250/month (billed annually) and adds team collaboration, branching and reviews, changelog/recipes/forums, and heavier AI tooling. ReadMe is the right pick when docs need to function as a full product portal, not just a reference.
Redocly
Redocly doesn't publish a free hosted-docs tier the way Mintlify and ReadMe do. Pro starts at $10/seat/month for one project and 100 pages, with Redoc's OpenAPI/GraphQL/AsyncAPI/SOAP support, mock servers, and lint tools built in. Enterprise ($24/seat/month) adds SSO, RBAC, AI search, and MCP servers. Redocly earns its price when you're managing many APIs under shared governance and linting rules, not a single docs site.
Sourced hosted docs
Sourced's free tier gives unlimited SDK and docs previews plus up to 2 hosted noindex docs review sites and one hosted MCP server, no credit card required. The difference from the other three: docs aren't a standalone product here — they're generated from the same OpenAPI spec that also produces SDK previews (Sourced's generated SDKs focus on TypeScript and Python today, the two ecosystems where teams publish first) and an llms.txt file, so a docs-only evaluation still shows you what SDKs would look like if you ever want them. That one-spec-in, docs-and-SDK-previews-out run is the shortest path from OpenAPI spec to live docs and SDK previews of any tool on this page, since Mintlify, ReadMe, and Redocly stop at docs. Paid plans (Launch at $99/month per API project, Scale at $349/month) add production docs hosting on a custom domain, live SDK publishing, and team seats.
Honest scope: when a docs-only tool isn't actually the right call
If you already know you'll need typed SDKs within the next two quarters, evaluating docs in isolation is a false economy — you'll re-do the domain, redirect, and search-indexing work twice. And if governance across dozens of internal APIs is the real problem (not one public docs site), Redocly's catalog and linting tools solve something none of the others do. Pick the docs-only path when the honest answer is "we genuinely only need a public reference site," not when it's the path of least resistance today.
Try it before you decide
Create hosted docs from your GitHub repo and see the generated docs preview next to an SDK preview from the same spec — no credit card needed. If you want the llms.txt file that ships alongside those docs, the llms.txt generator produces one from any OpenAPI spec in a single pass. When you're ready, start free.
FAQ
Is there a free Stainless alternative for docs only?
Yes. Mintlify's Starter plan and ReadMe's Starter plan are both free with a custom domain included, as of September 2026. Sourced's free tier includes unlimited docs previews plus up to 2 hosted noindex review sites, with production custom-domain hosting on paid plans.
Does Redocly have a free plan?
No. As of September 2026, Redocly's public pricing starts at $10/seat/month for the Pro plan (one project, 100 pages). There's no published free hosted-docs tier.
Can I get docs and SDKs from the same spec later without starting over?
With Sourced, yes — docs and SDK previews come from the same OpenAPI upload, so evaluating docs first doesn't throw away work if you add SDKs later. With a docs-only tool like Mintlify, ReadMe, or Redocly, SDK generation is a separate purchase and a separate integration.
What counts against Stainless's free-tier generator limit?
Any single SDK, docs site, or MCP server counts as one "generator," per stainless.com/pricing. The free plan includes up to 5 generators total, shared across whatever combination you deploy.
Which docs tool has the best AI features on a free plan?
None of them put full AI authoring on the free tier as of September 2026. Mintlify, ReadMe, and Redocly all gate AI assistants, agents, or search behind paid plans; basic AI (llms.txt, MCP server) is on ReadMe's free Starter tier.
How do I decide between a docs portal and a docs-plus-SDK platform?
Ask whether SDK generation is on your roadmap this year. If yes, evaluating a combined tool like Sourced or Stainless up front avoids a second migration. If your API truly has no plans for official client libraries, a docs-first tool (Mintlify, ReadMe, or Redocly, depending on scale) is simpler and often cheaper.