What Is a Preview Deployment?

Vercel builds three environments: production (your domain), preview (every non-production branch), and development (local). A preview deploy is a full build with its own URL, so a reviewer can click through the change without running anything locally.

How Do You Turn On Previews?

They’re on by default once your repo is connected. Push a branch, open a pull request, and Vercel comments the preview link on the PR automatically. No configuration step exists to enable it — only settings that change behavior.

1. Push a feature branch to your connected repo.
2. Wait for the Vercel check to finish (usually under two minutes).
3. Open the preview URL from the PR comment.
4. Test the change; leave review comments tied to the live version.

How Do Preview Environment Variables Work?

Vercel lets you scope variables per environment. A preview build can point at a staging database while production points at the live one — the same code, different config. Set this in Project Settings → Environment Variables and choose which environments each variable applies to.

How Do You Keep Previews Private?

Preview URLs are public by default, which is a problem for unreleased features. Vercel’s password protection and Vercel Authentication (available on paid plans) gate previews behind a login. For sensitive projects, enable protection before inviting outside reviewers.

Where Do Previews Get Messy?

Cost creeps up when dozens of branches deploy at once on metered plans, and stale preview environments can accumulate if you never clean up. Preview builds also consume build minutes, so a repo with frequent tiny commits can burn through your quota. Squash and deploy deliberately.

Quick Summary

• Vercel creates a preview URL for every non-production branch automatically.
• Preview variables can point at a staging database, separate from production.
• Preview URLs are public unless you enable password protection.
• Build minutes and bandwidth are consumed by each preview.
• Great for review workflows; prune stale branches to control cost.

Why Deploy Next.js on Vercel?

Because Vercel builds the framework, it understands Next.js features natively — server components, route handlers, image optimization, and incremental static regeneration all work with zero config. Other hosts can run Next.js, but you often maintain the plumbing yourself.

How to Deploy Your Next.js App

1. Sign up at vercel.com with GitHub or GitLab.
2. Click Add New → Project and import your repo.
3. Vercel auto-detects Next.js and fills in the build command.
4. Add environment variables in the Project Settings if your app needs them.
5. Click Deploy. Builds finish in under two minutes for typical apps.

Every subsequent push to main redeploys production; every pull request gets its own preview URL.

How Do You Attach a Custom Domain?

Open Project Settings → Domains, add your domain, and either switch nameservers to Vercel or add the recommended A and CNAME records. SSL is issued automatically and renews without action. Apex and www can both point at the project, with one redirecting to the other.

Is Vercel Free?

The Hobby plan is free for personal, non-commercial projects and includes 100 GB of fast data transfer per month. Commercial use technically requires the Pro plan at $20 per member per month, which also raises limits and adds team features.

What Surprises People?

Vercel’s serverless functions are stateless and have execution time limits, so long tasks fail. Bandwidth on the Hobby plan is measured on fast data transfer and can be exceeded by image-heavy sites. And if your database is far from the function region, every query pays a latency tax — pick regions deliberately.

Is Vercel the Right Host?

Yes for Next.js, React, and static front-ends with light API routes. If you’re running Python, containers, or long-lived servers, another platform fits better. Vercel optimizes for front-end velocity, not general-purpose compute.

Quick Summary

• Vercel deploys Next.js from Git with automatic detection and previews.
• Custom domains get automatic SSL; point DNS at Vercel or use their records.
• Hobby is free (100 GB/mo) but limited to non-commercial use.
• Functions are stateless with short time limits.
• Best for Next.js/front-end; choose differently for containers or long-lived servers.