February 21, 2025 / 456 /

How to Use Next.js 14 and 15 in Separate Branches and Deploy to Netlify

I deployed my project using Next.js 15 and React 19 (experimental).

While testing on Netlify, I noticed the blog posts on the site loaded slower compared to a project using Next.js 14.2.3.

I decided to revert to Next.js 14.2.3 for better performance but wanted to keep Next.js 15 on my GitHub in the main branch while working on the older version in a new branch.

How I Go About It

1. Created a Branch for Next.js 14

   I created a new branch called nextjsV14 in my local Next.js 15 project:

   git checkout -b nextjsV14
   

2. Set Up Next.js 14.2.3

   To spin up a fresh Next.js 14.2.3 project:

   • I deleted everything in the Next.js 15 project folder except .git and .gitignore. This retained the repository’s tracking history.
   • Ran:

     pnpx create-next-app@14.2.3 .
     

     I used pnpx because I prefer pnpm. If you use npm, you can run:

     npx create-next-app@14.2.3 .
     

     The . specifies that the installation should happen in the current directory.

3. Fixed .gitignore and Installed Dependencies

   • I deleted and recreated .gitignore to ensure proper formatting, adding entries like node_modules to exclude unnecessary files from being pushed.
   • Installed dependencies with:

     pnpm install
     

     (or npm install if you prefer).

4. Tested Locally

   • Started the development server:

     pnpm dev
     

     (or npm run dev for npm users).
   • Verified the project at localhost:3000.

5. Committed and Pushed Changes

   • Staged and committed the files:

     git add .
     git commit -m "Initialized Next.js 14.2.3 project"
     

   • Attempted to push but encountered an error:

     fatal: The current branch nextjsV14 has no upstream branch.
     To push the current branch and set the remote as upstream, use:
         git push --set-upstream origin nextjsV14
     

   • Fixed the error by setting the upstream branch:

     git push --set-upstream origin nextjsV14
     

   • This pushed the code to the nextjsV14 branch. Any future changes can now be pushed using git push.

6. Updated Netlify

   • Logged into the Netlify dashboard, unlinked the repository, and linked it again to switch the branch from main to nextjsV14.

So here are the steps I took to successfully maintained both Next.js 15 and 14.2.3 projects in the same repository,

improved performance with the older version, and deployed it on Netlify.