Understanding Fluid Compute on Vercel

Fluid compute is Vercel's next-generation execution model for Functions that provides a hybrid solution combining the flexibility of serverless with the efficiency of server-like capabilities. 12

What is Fluid Compute?

Fluid compute offers a blend of serverless flexibility and server-like capabilities, overcoming the limitations of both traditional approaches. Unlike standard serverless architectures that can face issues like cold starts and limited functionalities, Fluid compute delivers advantages of both worlds. 1

Key Benefits of Fluid Compute

Optimized Concurrency

Multiple invocations can share a single function instance, allowing for more efficient resource usage. This is especially valuable for I/O-bound tasks like fetching embeddings, querying vector databases, or calling external APIs. 13

Dynamic Scaling

Fluid compute automatically optimizes existing resources before scaling up to meet traffic demands. This ensures low latency during high-traffic events and cost efficiency during quieter periods. 12

Background Processing

After fulfilling user requests, you can continue executing background tasks using waitUntil. This allows for a responsive user experience while performing time-consuming operations like logging and analytics in the background. 12

Cold Start Optimizations

Fluid compute reduces cold starts through:

• Bytecode caching: Automatically pre-compiles function code to minimize startup time
• Pre-warmed instances: Keeps functions ready to handle requests without cold start delays 12

Cross-Region Failover

Ensures high availability by first failing over to another availability zone within the same region if one goes down. If all zones in that region are unavailable, Vercel automatically redirects traffic to the next closest region. 12

How to Enable Fluid Compute

To enable Fluid compute:

1. Navigate to your project in the Vercel dashboard
2. Click on the Settings tab and select the Functions section
3. Scroll to the Fluid Compute section and enable the toggle
4. Redeploy your project to apply the changes 13

Supported Runtimes

Fluid compute is currently available for:

• Node.js (version 20+)
• Python 13

Default Settings by Plan

Fluid Compute includes default settings that vary by plan:

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