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Fern

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Generate and publish SDKs and create stunning API documentation from your API specification.

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Reviews onG2
1 review tracked

The Bottom Line

Entry price

Free plan available, paid tiers above

Biggest pro

Generates high-quality, language-idiomatic SDKs, saving significant development time.

Biggest con

No free tier available, requiring a commitment to a paid plan.

TL;DR - Fern

  • Generates idiomatic SDKs in multiple languages from API specifications.
  • Automates the creation of interactive, SEO-optimized API documentation.
  • Saves engineering time and enhances the developer experience for API consumers.
Pricing: Free plan available
Best for: Growing teams

What is Fern?

Editorial review
Fern is a platform that helps companies elevate their developer experience by automating the generation of SDKs and creating comprehensive API documentation. It allows users to start with an API specification (OpenAPI, AsyncAPI, OpenRPC, gRPC, or Fern Definition) and automatically generate client libraries in multiple languages, including TypeScript, Python, Go, Java, Ruby, C#, and PHP. Beyond SDK generation, Fern also provides a robust documentation platform. It enables users to create SEO-optimized, versioned API documentation with features like API key injection, access control, and interactive API explorers. The platform supports docs-as-code workflows, allowing documentation to be versioned and released using Git, and offers customization options with JavaScript, CSS, and React components. Fern aims to save engineering time and improve the developer experience for API consumers.

Available on: Web

how we evaluateSourcebuildwithfern.com ↗

Pros & Cons

Pros

  • Generates high-quality, language-idiomatic SDKs, saving significant development time.
  • Provides a comprehensive and customizable documentation platform with advanced features.
  • Supports various API specification formats, offering flexibility.
  • Includes built-in features like OAuth, pagination, and retries in generated SDKs.
  • Offers enterprise solutions with dedicated support for perfecting OpenAPI specs and launching SDKs.

Cons

  • No free tier available, requiring a commitment to a paid plan.
  • Swift and Rust SDK generation are listed as 'coming soon', limiting current language support.

Ratings Across the Web

5(1 reviews)

Fern holds an aggregate rating of 5 out of 5 from 1 reviews across G2, last checked September 22, 2026.

G21 reviews
5/5

Ratings aggregated from independent review platforms. Learn more

Preview

Key Features

SDK Generation (TypeScript, Python, Go, Java, C#, PHP, Ruby)Supports OpenAPI, AsyncAPI, OpenRPC, gRPC, Fern Definition specsCustom code extension for generated SDKsAutomated package publishing to registries (npm, pypi, maven)OAuth 2.0 authentication support in SDKsServer-sent events (SSE) support in SDKsAutomatic pagination in SDKsPolymorphism (Unions) handling in SDKs

Pricing Plans

Pricing checked Sep 20, 2026

Hobby

Free

  • $0/month official, free forever
  • 2 team members
  • 250 AI credits
  • Custom domain, password docs

Team

$150/month

  • $150/month official
  • Yearly toggle saves 25%
  • 5 members, 1,000 AI credits
  • PDF exports, version switcher

Enterprise

Custom

  • Quote
  • SSO, RBAC, self-host
  • Remove Fern branding
Calculate your costView full pricing

Is Fern worth the price?

76/100

Fern Docs Hobby is $0 forever: 2 members, 250 AI credits, custom domain, password-protected docs.

Team is $150/month. Yearly toggle saves 25% (they do not print the yearly cash total).

Enterprise is a quote: visitor auth, RBAC, translations, self-host, remove branding. This is best for a solo OpenAPI site at $0, or a small team that will actually use the 1,000 credits at $150.

Hidden Costs & Gotchas

Team yearly is 25% off. They do not print the yearly dollar total. Do the math at checkout.

Hobby is 2 members and 250 AI credits. Over that is Team or Enterprise.

How Fern's pricing compares

At $150/mo, Fern is mid-range of its 4 direct competitors ($19 to $349/mo across the set).

Postman
$19
Stoplight
$56
Apiary
$99
Fern
$150
ReadMe
$349

Entry paid plan, monthly. Pricing checked Sep 20, 2026.

Reviews

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Best Fern Alternatives

Top alternatives based on features, pricing, and user needs.

View full list →
Postman logo
PostmanFreemium

API platform for building and using APIs

4.6
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StoplightFreemium

Visually design, manage, and publish OpenAPI specs

4.4
Kong logo
KongFreemium

Route, secure, and observe APIs with a scalable platform

4.2
SwaggerHub logo
SwaggerHubPaid

Design, test, and govern AI-ready APIs with enhanced collaboration and automation.

4.2
ReadMe logo
ReadMeFreemium

Developer documentation platform

4.5
Apiary logo
ApiaryFreemium

Design and document APIs before you code

4.3
See all developer tools →

Still deciding?

Most buyers shortlist 2 or 3 tools before committing. Pull a side-by-side comparison or browse the full alternatives shortlist below.

All Fern alternatives6+ tools ranked, pricing + verdict per pickFern vs PostmanHead-to-head: features, pricing, who winsFern vs StoplightHead-to-head: features, pricing, who winsFern vs KongHead-to-head: features, pricing, who wins

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Fern FAQ

How does Fern help improve the developer experience for API consumers?

Fern elevates the developer experience by automating the generation of client libraries in multiple languages, such as TypeScript, Python, and Java, directly from an API specification. It also provides comprehensive, interactive, and SEO-optimized API documentation, making it easier for developers to understand and integrate with APIs.

Which teams would benefit most from using Fern?

Teams focused on API development and developer relations would find Fern most beneficial, as it streamlines the creation of high-quality SDKs and robust API documentation. It is particularly useful for engineering teams looking to save development time and improve the onboarding experience for API consumers.

How does Fern compare to ReadMe for API documentation?

Fern provides a comprehensive documentation platform with features like API key injection and access control, similar to ReadMe. However, Fern also automates the generation of language-idiomatic SDKs directly from various API specifications, a core capability that complements its documentation offerings.

What kind of API specifications does Fern support for generating SDKs?

Fern supports a wide array of API specification formats for generating SDKs, including OpenAPI, AsyncAPI, OpenRPC, gRPC, and its own Fern Definition. This flexibility allows users to leverage existing specifications to automate client library creation.

What are the current limitations regarding language support for SDK generation in Fern?

While Fern supports major languages like TypeScript, Python, Go, Java, Ruby, C#, and PHP for SDK generation, support for Swift and Rust is currently listed as 'coming soon'. This means users requiring SDKs in these specific languages may need to wait for future updates.

How is Fern priced?

Fern is offered as a paid product and does not include a permanently free tier. Users interested in the platform will need to commit to one of its paid plans to access its features for SDK generation and API documentation.

Can Fern integrate with existing development workflows for documentation?

Yes, Fern supports docs-as-code workflows, enabling documentation to be versioned and released using Git, which integrates well with existing development practices. It also offers customization options with JavaScript, CSS, and React components for tailored documentation experiences.

Source: buildwithfern.com

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