5 Common Mistakes When Configuring Vercel for Your Next Project

When you're diving into a new project and choosing Vercel for your deployments, the excitement can sometimes cloud your judgment. It's easy to overlook critical configuration steps that can lead to headaches down the line. We've been there, and we've made these mistakes ourselves. Here are the top five pitfalls to avoid when configuring Vercel in 2026.

1. Ignoring Environment Variables

The Mistake: Many developers skip setting up environment variables properly, which can result in broken builds or failed API calls in production.

What to Do: Ensure you define all necessary environment variables in the Vercel dashboard. This includes API keys, database URLs, and any other sensitive information.

Our Take: We learned this the hard way when our production build failed because we forgot to add an API key. Now, we always double-check our environment settings before deploying.

2. Misconfiguring the Build Command

The Mistake: Using incorrect build commands can lead to deployment failures or unexpected behavior in your application.

What to Do: Verify that your build command is correctly specified in the Vercel settings. Common commands include npm run build or next build, depending on your framework.

Limitations: Not all frameworks are straightforward. If you're using a custom setup, ensure that your command reflects the structure of your project.

3. Overlooking Custom Domains and Redirects

The Mistake: Forgetting to configure custom domains and redirects can lead to users landing on the wrong pages or seeing error messages.

What to Do: Set up your custom domain in Vercel and configure any necessary redirects in the vercel.json file or through the dashboard.

Our Take: We once launched a project without proper domain setup, resulting in a lot of confused users. Now, we prioritize this step to avoid traffic loss.

4. Not Taking Advantage of Preview Deployments

The Mistake: Some developers don’t utilize Vercel's preview deployments, which can lead to under-testing before going live.

What to Do: Use preview deployments to test changes in a live environment before merging them into your main branch. This helps catch issues early.

Cost Consideration: Vercel offers this feature in all plans, but heavy usage can lead to increased costs if you exceed the limits.

5. Failing to Optimize for Performance

The Mistake: Skipping performance optimizations can lead to slower load times, which can hurt user experience and SEO.

What to Do: Leverage Vercel's built-in features like image optimization and static site generation. Use tools like Lighthouse to analyze performance.

Our Experience: We initially neglected performance optimizations, leading to a sluggish app. Now, we make it a point to review performance metrics after every deployment.

Conclusion: Start Here

To avoid these common mistakes, take the time to carefully configure your Vercel settings. Double-check your environment variables, build commands, domain setups, and performance optimizations. By following these steps, you can ensure a smoother deployment process and a better experience for your users.

If you're looking for more tips on tools and configurations, check out our podcast where we share our experiences and lessons learned while building in public.