next-upgrade

To upgrade Next.js safely, read package.json for current versions, apply official codemod transforms first, update Next.js and React dependencies, then run build and runtime checks to catch migration errors.

The best way to use Next.js codemods is running npx @next/codemod transforms before updating package dependencies, ensuring automated breaking changes are resolved first, followed by manual fixes from the version-specific migration guide.

You need to run codemods during any major or incremental Next.js release upgrade to automatically handle breaking changes and apply required migrations before you update dependencies in package.json.

Yes, you can upgrade Next.js and React dependencies together, but you must align them with official migration guidance and run @next/codemod transforms first to ensure next.config and package dependencies match the target version.

A Next.js build fails after updating package.json when required codemods are skipped or next.config is misaligned, making it necessary to run version-specific migration steps and codemod transforms before validating the build.

Yes, the Next.js upgrade process requires manual changes after running codemods, because you must resolve remaining breaking changes from the official upgrade guide and perform build and runtime checks to verify the migration.