Paste OpenAPI/Swagger, Postman, GraphQL, gRPC, AsyncAPI, RAML or API Blueprint — and get any other format back, validated and honest about anything that can’t be carried across. No account, no upload, no install.
What it is
Migrating an API description between spec versions usually means installing a toolchain or pasting your spec into someone’s server. This does it in the browser tab — instantly, and privately.
Parsing and conversion happen locally in a Web Worker. Your spec never leaves the page — verified: a full conversion fires zero network requests.
Downgrades lose features. Every dropped or approximated construct is surfaced as a warning — you’re never handed a silently-broken spec.
Conversions are tested against a real OpenAPI/Swagger validator, with a regression suite covering the awkward edge cases.
How it works
Rather than a maze of pairwise converters, every spec is normalised into one canonical representation — OpenAPI 3.1 — and then written out to whatever you asked for. Add a format once as an importer and an exporter, and it converts to and from everything else.
Honest about fidelity
Upgrades are essentially lossless. Downgrades trade away features the older spec can’t express — and the tool tells you exactly which, instead of pretending nothing changed.
Version upgrades within the OpenAPI family carry everything across.
Type unions, webhooks, multiple examples, JSON-Schema-2020 keywords, callbacks — each collapse or drop is warned.
Postman, AsyncAPI, GraphQL, gRPC, RAML and API Blueprint convert too — structurally different formats, mapped best-effort with clear warnings.
Coverage
| Format | As source | As target | Status |
|---|---|---|---|
| Swagger 2.0 | Yes | Yes (lossy) | Live |
| OpenAPI 3.0.x | Yes | Yes | Live |
| OpenAPI 3.1.x | Yes | Yes | Live |
| Postman Collection v2.1 | Yes | Yes | Best-effort |
| AsyncAPI 2.x / 3.x | Yes | Yes | Best-effort |
| GraphQL SDL | Yes | Yes | Best-effort |
| gRPC / Protobuf (proto3) | Yes | Yes | Best-effort |
| RAML 1.0 / 0.8 | Yes | Yes | Best-effort |
| API Blueprint | Yes | Yes | Best-effort |