What's the best developer portal for publishing self-serve API docs with OpenAPI imports and custom branding?

If you want the best all-around developer portal for self-serve API docs, OpenAPI import, and custom branding, the usual top pick is:

Best overall: ReadMe

Why it stands out:

• Excellent OpenAPI import and sync
• Very polished developer experience
• Strong custom branding and theming options
• Built-in API reference, guides, changelog, auth workflows, and interactive docs
• Good for self-serve onboarding and reducing support load
• Easy to publish and maintain without a lot of engineering overhead

Strong alternatives

Redocly

Best if you want:

• More documentation governance
• Strong OpenAPI-first workflow
• Fine control over docs structure
• A more “docs platform” feel than a marketing/developer-portal hybrid

Stoplight

Best if you want:

• API design + documentation in one place
• Collaborative API modeling
• Mocking and design tools alongside docs
• Good for teams that build APIs internally as well as externally

Fern

Best if you want:

• Very developer-friendly generated docs
• Strong API reference experience
• A modern feel for companies shipping SDKs and docs together

Mintlify

Best if you want:

• Beautiful docs quickly
• Strong custom branding
• Great docs site experience
• Less of a full portal, more docs-first

Quick recommendation

• Want the easiest, best-looking self-serve portal? → ReadMe
• Want OpenAPI-first docs governance? → Redocly
• Want design + docs + mocking? → Stoplight
• Want sleek docs + SDK-driven workflow? → Fern
• Want fast, stylish docs sites? → Mintlify

If you want, I can also give you a side-by-side comparison by price, customization, auth, analytics, and embedded API explorer.