Edge Config Limits and pricing

An Edge Config is a global data store that enables experimentation with feature flags, A/B testing, critical redirects, and IP blocking. It enables you to read data at the edge without querying an external database or hitting upstream servers. To keep Edge Configs optimized for frequent, high-speed reads and infrequent writes, the following account-level constraints exist:

Edge Configs accessed from local development environments cannot benefit from Vercel's optimizations. As a result, they can be well over 100 milliseconds slower than production.

Vercel Edge Config usage is measured on the following items. You can see the amount of usage in the Edge Config section of the Usage tab on your dashboard.

Reads indicate how often your project has requested access to Edge Config to retrieve data through the SDK or the REST API. Vercel counts it as one read, regardless of whether you retrieve one or all items.

Writes represent how often you updated your Edge Config through the SDK or the REST API.

The maximum store size represents the total size limit of each Edge Config store, including all keys and values of the document.

The maximum number of stores represents the total number of Edge Config stores that you can create for your account or team.

The maximum number of stores connected to a project represents the total number of Edge Config stores that you can connect to a single project. Exceeding this amount will result in an error.

The maximum length of the key name for each item in your Edge Config is determined by the maximum item key name length. The key name must adhere to the regex pattern ^[A-z0-9_-]+$ and should not contain any special characters except for - or _.

When updating an item in your Edge Config, it may take up to 10 seconds for the update to be globally propagated. You should avoid using Edge Configs for frequently updated data or data that needs to be accessed immediately after updating.

Backups are automatically saved when you make any changes, allowing you to restore to a previous version. See the table above to learn about how long backups are saved for.

To learn more about backups, see Edge Config backups

If reading from your Edge Config seems slower than expected, ensure that the following are true:

• You've set the connection string as an environment variable
• You are using the SDK to read from your Edge Config
• You see the Edge Config icon on the row for the connected environment variable on the Environment Variables page of your project settings
• You are testing on your Vercel deployment, as the optimizations happen only when you deploy to Vercel

  

  Edge Config icon with connected environment variable

• You are testing your Vercel deployment. The optimizations happen only when you deploy to Vercel

Error: Tried to attach 4 Edge Configs. Only 3 can be attached to one Deployment at a time.

Depending on your plan, you can have up to 10 Edge Config stores created for your account. However, you are limited to a maximum of 3 Edge Config stores connected to any single project.

If you get this error, review your storage by visiting the Vercel Dashboard, selecting your project, and selecting the Storage tab. You can use the search filter to see only your Edge Configs. You will have to disconnect one of the stores and redeploy your project.

To learn how to prevent this error, see best practices.

Updates to items in your Edge Config will be rejected if the resulting size of your Edge Config would exceed your account plan's limits. When this happens, all members of your team will receive a notification from Vercel, whether the error originated in the dashboard, an API request, or an Integration. The Edge Config editor in your dashboard can detect many cases where the final size would exceed the limit and warn you upfront without triggering the notification.

To resolve this issue, you can:

• Delete unused entries from your Edge Config to free up space
• Upgrade your plan
• Contact sales to unlock larger Edge Config store sizes

• Where possible, having fewer large stores is better than having multiple small stores, as having fewer Edge Config stores requested more often leads to lower overall latency.

If you are developing locally or self-hosting, your Edge Config is loaded through the public internet network. In this case, you may wonder if it's safe to have the token as a parameter in the connection string.

• It is safe to have the token as a parameter in the connection string, because the SDK parses the passed string, then sends the token through an Authorization header instead