There's no single cheapest Stainless alternative — the answer changes with team size, because pricing units differ (per seat, per API, per endpoint, per SDK, or a flat project rate). Below is the math at three team sizes using only publicly listed prices as of September 2026. Where a vendor doesn't publish a number — Stainless past its free tier, Fern past its free tier, and Speakeasy's self-serve pricing — that's stated explicitly, because that itself is the point: you can't price-compare what isn't published.
A pricing comparison assumes you can actually buy the thing — as of September 2026, you can't sign up for Stainless. Per Stainless's own announcement, Stainless is joining Anthropic, and new signups, projects, and SDKs stopped the day that post went live; the company says it's winding down its hosted SDK generator and docs platform. WorkOS's coverage summarizes the effect bluntly: the hosted SDK generator is going away. The $0 Stainless rows in the tables below are historical reference, not a live price you can act on today. Your spec and stainless.yml are still yours — see the migration guide.
The rule for this post
Every price below is either quoted from the vendor's public pricing page (fetched directly) or marked as not public. No estimates, no "probably around." If a vendor gates pricing behind "contact sales," this post says so instead of guessing a number.
Team size 1: solo builder, one API
One person, one OpenAPI spec, evaluating before committing money.
| Tool | Monthly cost | What it gets you |
|---|---|---|
| Sourced | $0 | Unlimited previews, 2 hosted noindex docs sites, TS + Python SDKs |
| Fern | $0 | Docs, "free forever," per their pricing page |
| Scalar | $0 | Docs + landing page, 1 SDK ≤25 endpoints, ≤3 APIs |
| ReadMe | $0 | Starter: custom domain, interactive reference |
| GitBook | $0 | 1 site, 1 user, MCP server |
| Stainless | $0 | ≤25 endpoints, 5 generators, no docs |
| Speakeasy | $0 | 1 SDK, ≤50 methods |
| Bump.sh | $50 | No free plan for non-OSS projects — Basic starts here |
| Redocly | $10 | Pro, 1 seat, 1 project, 100 pages — docs only, no SDK generation |
| OpenAPI Generator / Kiota | $0 | Unlimited, self-hosted, self-maintained |
At this size, almost everything is free except Bump.sh (no free tier for non-open-source projects) and Redocly (no free plan at all — Pro starts at $10/seat/month for docs only, with SDK generation not part of that product). Sourced's row is also the only free tier among the platforms compared here that pairs unlimited previews with no credit card. The Stainless row is included for reference only — see above.
Team size 2: small team, 2–3 people, wants a custom domain
The team has outgrown "evaluating" and needs at least one production docs domain.
| Tool | Monthly cost | Basis |
|---|---|---|
| Sourced | $99 | Launch plan — 1 API project, hosted docs, custom domain, npm/PyPI publishing |
| Redocly | $30 | Pro, 3 seats × $10/seat — docs and hosting only, no SDK generation |
| GitBook | $89 | Premium $65/site + $12/user × 2 additional users |
| Bump.sh | $120 | Pro — 30 API docs, 50 MCP tools, custom domain |
| ReadMe | $250 | Pro, billed annually — team collaboration, private docs |
| Scalar | $150–$300 | Pro at $150/mo covers docs + 1 SDK ≤100 endpoints for up to 15 APIs; a second SDK language adds another $150/mo add-on |
| Fern | Not public | Only Free ($0) and Enterprise (custom, "Book a demo") are listed — no published price between them |
| Stainless | Not public | Exceeding the free plan auto-enrolls a 30-day trial of a paid plan; no dollar figure is shown on the pricing page |
| Speakeasy | Not public | Pricing page no longer lists self-serve tiers |
This is where the comparison stops being apples-to-apples. Redocly's $30/mo is docs hosting only — you'd still need a separate SDK generator. Scalar's $150/mo includes one SDK language; a second language is a separate $150/mo add-on, so two-language SDK coverage plus docs runs closer to $300/mo. Sourced's $99/mo bundles SDKs — Sourced's generated SDKs focus on TypeScript and Python today, the two ecosystems where teams publish first — plus docs and a custom domain in one price, which is the more relevant comparison if your API needs both.
Team size 3: growth-stage team, multiple APIs, ~10 people
Several API projects, a full team reviewing changes, custom domains live.
| Tool | Monthly cost | Basis |
|---|---|---|
| Sourced | $349 | Scale plan — more API projects, more hosted docs sites, team capacity, production custom domains |
| Redocly | $240 | Enterprise, 10 seats × $24/seat — docs and governance only, no SDK generation |
| GitBook | $357 | Ultimate $249/site + $12/user × 9 additional users |
| Scalar | $600+ | Business plan, up to 25 APIs, 1 SDK ≤250 endpoints, 10 seats — additional SDK languages are separate add-ons on top |
| Bump.sh | Not public | Custom tier past Pro is "Contact Sales" |
| ReadMe | Not public | Enterprise is contact-sales only |
| Fern | Not public | Enterprise, "Book a demo" |
| Stainless | Not public | Enterprise pricing not listed |
| Speakeasy | Not public | Pricing page is contact-sales/enterprise only |
At this size, five of nine vendors compared don't publish a number at all. The ones that do (Sourced, Redocly, GitBook, Scalar) are priced on different units — flat project tiers, per-seat, per-user, and API-count-plus-endpoint-caps respectively — so "cheapest" depends heavily on how many seats and APIs your team actually has.
Why so many prices aren't public
Contact-sales gating past a certain size is normal in this category — Stainless, Fern, Speakeasy, Bump.sh (past Pro), and ReadMe (past Pro) all do it. It usually means the vendor negotiates on endpoint count, seat count, or SLA terms per customer. The honest version of "cheapest alternative" content names this instead of inventing a number: if a vendor won't publish a price, you can't include it in a fair comparison, and asking their sales team for a quote is the only way to get a real figure for your team size.
Honest scope
Price-per-month is not the same as cost-per-outcome. Redocly's per-seat docs pricing looks cheap at small team sizes but doesn't generate SDKs at all — you'd add a second tool and a second bill. Scalar's per-SDK-language add-on pricing means multi-language coverage compounds fast. If your requirement is genuinely "docs only, cheapest possible," Redocly or GitBook's free tier likely wins. If it's "docs plus SDKs in one bill," compare Sourced's flat per-project pricing against the sum of a docs tool plus a separate generator, not against the docs tool alone.
FAQ
Is Sourced the cheapest option overall?
It depends on what you're buying. For docs-plus-SDKs in one price, Sourced's $99/mo Launch plan is priced lower than stacking a docs tool with a paid SDK add-on in the team-size-2 comparison above. For docs-only at small team sizes, Redocly's per-seat Pro plan can be cheaper.
Why don't you list a dollar amount for Stainless, Fern, or Speakeasy above the free tier?
Because none of the three publishes one on their pricing page as of September 2026. Stainless auto-enrolls overage into an unpriced trial; Fern's pricing page shows only Free and custom Enterprise; Speakeasy's pricing page is now contact-sales/enterprise-only.
Does "free" count as "cheapest"?
Only if the free tier actually covers your use case. See the free Stainless alternatives post for what each free tier excludes before you rely on it long-term.
Are open-source generators cheaper than all of these?
In dollar terms, yes — OpenAPI Generator and Kiota are free with no tiers. The tradeoff is your own engineering time for hosting, publishing, and maintenance; see the open-source alternative post.
Why is Scalar's pricing hard to compare directly?
Because SDK languages are priced as add-ons on top of the base plan — a two-language SDK plus docs costs more than the headline Pro price alone.
Where can I see exact current Sourced pricing?
Sourced vs Stainless pricing has the current numbers; they can change, so treat this post's figures as a September 2026 snapshot.
Run the numbers for your team
Create hosted docs from your repo free to see the actual output before comparing bills, or start free with a spec upload. Validate the spec first with the OpenAPI validator — a clean spec is free either way, and it's what every one of these tools needs before generation.