OpenAPI Diff Tool

Compare two OpenAPI specifications side by side. Detect breaking changes, classify semver impact, and get actionable migration guides — instantly, in your browser.

Open the Playground

What You Get

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Breaking Change Detection

Identifies 17 types of breaking changes including removed endpoints, type changes, removed enum values, and new required parameters.

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Semver Classification

Automatically classifies changes as MAJOR, MINOR, or PATCH and computes the next version number based on the spec's current version.

Migration Guides

Every breaking change includes a step-by-step migration guide so your team knows exactly what to update in client code.

Three Ways to Diff

1

Browser Playground

Paste two specs into the Playground and click Analyze. No install, no account, no API keys. Results in milliseconds.

2

CLI

Run diffs locally or in CI with one command.

$ npx delimit-cli diff old.yaml new.yaml
3

GitHub Action

Automatically diff your OpenAPI spec on every pull request and block merges on breaking changes.

uses: delimit-ai/delimit-action@v1

Supported Formats

OpenAPI 3.0OpenAPI 3.1Swagger 2.0YAMLJSON

Try It Now

No install required. Paste your specs and see what changed.