A modern alternative to Swagger Editor

Swagger Editor defined the category. OASForge keeps what made it great — code on the left, live rendered docs on the right — and rebuilds the rest for how specs are written today.

Side by side

CapabilityOASForgeSwagger Editor
Dark themeNative, four palettesNo
Works fully offlineYes — PWA and a single-file buildPartially
“Try it out” without a backendYes — built-in stateful mock serverNo
Quick fixes on validation issuesYes, one clickNo
Postman collection importYes, automaticNo
Insert menu for OpenAPI structureYesNo
Version history with diffYes, in local storageNo
OpenAPI 3.2 awarenessYesDepends on version
Account requiredNeverNo

The mock server changes how you demo

The default server in the preview is an in-browser mock: POST really creates records (kept in memory), GET lists them back, PUT/PATCH/DELETE update and remove. Endpoints without stored data answer with schema-derived examples. You can demo a realistic API flow from a laptop with no network at all.

Honest limits

OASForge is a client-side workbench: it does not generate server stubs or client SDKs the way swagger-codegen integrations do, and very large multi-file specs must be bundled into one document first. For writing, validating, mocking and sharing a spec, it does more — with nothing to install.

No signup, no install — the editor runs entirely in your browser.

Open the OASForge editor