Intermediate
How to configure multi-region function deployment on Vercel
Quick Answer
Configure multi-region function deployment on Vercel by adding region specifications to your vercel.json file and using the functions configuration property. You can specify different regions for individual functions or set a default region for all functions.
Prerequisites
- Active Vercel account with Pro or Enterprise plan
- Existing Next.js or Node.js project with serverless functions
- Basic understanding of serverless functions and regions
- Git repository connected to Vercel
1
Create or update your vercel.json configuration file
In your project root, create a
vercel.json file if it doesn't exist. This file will contain all your deployment configuration including region settings. Ensure the file is in your project's root directory alongside your package.json.Tip
Use a JSON validator to check your vercel.json syntax before deployment to avoid configuration errors.
2
Configure default region for all functions
Add the
functions property to your vercel.json with a default region setting:{
"functions": {
"pages/api/**/*.js": {
"regions": ["iad1", "fra1", "syd1"]
}
}
}Tip
Start with regions closest to your primary user base for better performance.
3
Set region-specific function configurations
Configure individual functions for specific regions by targeting exact file paths:
{
"functions": {
"pages/api/users.js": {
"regions": ["iad1", "fra1"]
},
"pages/api/analytics.js": {
"regions": ["syd1", "hnd1"]
}
}
}Tip
Deploy user-facing functions to multiple regions while keeping admin functions in fewer regions to optimize costs.
4
Choose appropriate regions based on user location
Select regions strategically using Vercel's available options:
iad1 (US East), sfo1 (US West), fra1 (Europe), hnd1 (Asia-Pacific), syd1 (Australia). Consider your analytics data to determine where most requests originate from.Tip
Use 2-3 regions maximum per function to balance performance and cost-effectiveness.
5
Configure environment variables per region
Set region-specific environment variables through the Vercel Dashboard under Settings → Environment Variables. Use the Region dropdown to assign different values per region. This is useful for database connections or region-specific API endpoints.
Tip
Use consistent naming conventions like DATABASE_URL_US and DATABASE_URL_EU for clarity.
6
Deploy and verify multi-region configuration
Push your changes to trigger a deployment, or run
vercel --prod locally. Check the deployment logs in the Vercel Dashboard to confirm functions are deployed to specified regions. The Functions tab will show regional distribution.Tip
Use the Vercel CLI command 'vercel logs' to monitor function execution across different regions.
7
Test function performance across regions
Use tools like Vercel's built-in analytics or external services to test response times from different geographical locations. Access your deployed functions and monitor the Analytics tab in your Vercel Dashboard to see regional performance metrics.
Tip
Test during peak hours in different time zones to get realistic performance data.
8
Monitor and optimize regional deployment
Review function invocation data in the Vercel Dashboard Analytics section. Look for patterns in regional usage and adjust your
vercel.json configuration accordingly. Remove underutilized regions to optimize costs while maintaining performance.Tip
Set up monitoring alerts for function errors or high latency in specific regions.
Troubleshooting
Functions not deploying to specified regions
Verify your
vercel.json syntax is correct and the file paths match your actual function locations. Check that you're on a Pro or Enterprise plan, as multi-region deployment isn't available on Hobby plans.High latency despite multi-region setup
Check if you're using the correct region codes in your configuration. Ensure your database or external APIs are also geographically distributed, as functions may still need to connect to distant resources.
Environment variables not working in specific regions
Verify environment variables are set for each target region in the Vercel Dashboard. Use the
vercel env ls command to check which variables are available in which regions.Increased costs after multi-region deployment
Review your function usage analytics and remove regions with low traffic. Consider consolidating similar functions or using edge functions for simpler operations that don't require full regional deployment.
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