Vercel Environment Variables Not Loading in Deployment
Your application builds successfully but environment variables aren't available at runtime in Vercel. Features depending on env vars fail in production, though they work in local development.
Environment variables don't load in Vercel when they're not properly configured in project settings, use incorrect naming conventions, or are set for wrong deployment environments.
Error Messages You Might See
Common Causes
- Environment variables not added to Vercel project settings (must be set in UI, not just .env)
- Variables set for wrong environment (e.g., production-only but accessing in preview deployment)
- Using .env file instead of Vercel Settings, and .env not committed (ignored by git)
- Variable names not prefixed with NEXT_PUBLIC_ for client-side access
- Redeployment not triggered after changing env vars, using cached build
How to Fix It
Set in Vercel UI: Go to Project Settings > Environment Variables. Add each variable for Production, Preview, Development as needed.
Restart deployment: After changing env vars, trigger new deployment: push to git or click 'Redeploy' button in Vercel.
Client-side vars: Prefix with NEXT_PUBLIC_: NEXT_PUBLIC_API_URL=https://api.example.com
Server secrets: Don't prefix secrets: DATABASE_URL=postgres://... keeps them server-only.
Real developers can help you.
Tejas Chokhawala
Full-stack engineer with 5 years experience building production web apps using React, Next.js and TypeScript.
Focused on performance, clean architecture and shipping fast.
Experienced with Supabase/Postgres backends, Stripe billing, and building AI-assisted developer tools.
Pratik
SWE with 15+ years of experience building and maintaining web apps and extensive BE infrastructure
Alvin Voo
I’ve watched the tech landscape evolve over the last decade—from the structured days of Java Server Pages to the current "wild west" of Agentic-driven development. While AI can "vibe" a frontend into existence, I specialize in the architecture that keeps it from collapsing.
My expertise lies in the critical backend infrastructure: the parts that must be fast, secure, and scalable. I thrive on high-pressure environments, such as when I had only three weeks to architect and launch an Ethereum redemption system with minimal prior crypto knowledge, turning it into a major revenue stream.
What I bring to your project:
Forensic Debugging: I don't just "patch" bugs; I use tools like Datadog and Explain Analyzers to map out bottlenecks and resolve root causes—like significantly reducing memory usage by optimizing complex DB joins.
Full-Stack Context: Deep experience in Node.js and React, ensuring backends play perfectly with mobile and web teams.
Sanity in the Age of AI: I bridge the gap between "best practices" and modern speed, ensuring your project isn't just built fast, but built to last.
Stanislav Prigodich
15+ years building iOS and web apps at startups and enterprise companies. I want to use that experience to help builders ship real products - when something breaks, I'm here to fix it.
PawelPloszaj
I'm fronted developer with 10+ years of experience with big projects. I have small backend background too
Matthew Jordan
I've been working at a large software company named Kainos for 2 years, and mainly specialise in Platform Engineering. I regularly enjoy working on software products outside of work, and I'm a huge fan of game development using Unity. I personally enjoy Python & C# in my spare time, but I also specialise in multiple different platform-related technologies from my day job.
ISHANTDEEP SINGH
Senior Software Engineer with 7+ years of experience in React, JavaScript, TypeScript, Next.js, and Node.js. I’ve also worked as a tech lead for startups, owning end-to-end technical execution including architecture, development, scaling, and delivery. I bring a strong mix of hands-on coding, product thinking, and technical leadership, and I’m comfortable building products from scratch as well as improving and scaling existing systems.
Meïr Ankri
Full-stack developer specializing in React / Next.js / Node.js with 6+ years of experience. I've worked across various sectors including automotive (Reezocar/Société Générale), healthcare (Medical Link SaaS), and e-commerce (Glasman). I build web apps end-to-end, from architecture to production, with a focus on scalability, performance, and code quality. I also mentor junior developers and contribute to technical decisions and code reviews.
Matthew Butler
Systems Development Engineer @ Amazon Web Services
Victor Denisov
Developer
You don't need to be technical. Just describe what's wrong and a verified developer will handle the rest.
Get HelpFrequently Asked Questions
How do I add environment variables in Vercel?
Go to project > Settings > Environment Variables. Add each variable, select which environments (Production, Preview, Development) it applies to.
Should I commit .env file to git?
Never commit secrets. Commit .env.example with placeholder values. Use Vercel UI for actual secrets.
Why is API_KEY undefined in production?
Check 1) Variable set in Vercel Settings 2) Correct environment selected (Production vs Preview) 3) Deployment restarted after adding variable.