--- source_url: "https://docs.netlify.com/build/functions/configuration/" title: "Configuration for functions | Netlify Docs" mirrored_at: 2026-08-10T01:06:42.086Z host: docs.netlify.com cited_in_42a: true mirror_canonical: "https://index.42a.ai/docs.netlify.com/build/functions/configuration/index" --- > **Original source:** https://docs.netlify.com/build/functions/configuration/ This page documents the settings you can customize to control how your functions are built, deployed, and executed, along with the default values that apply when you leave a setting unspecified. Select your function language: ## Default values Unless customized, every function deploys with: Setting Default Configurable? Region `cmh` (US East, Ohio) 1 Yes — [Region](#region) Memory 1024 MB Yes — [Memory or vCPU](#memory-or-vcpu) Synchronous execution limit 60 seconds No Scheduled execution limit 30 seconds No Background execution limit 15 minutes No Buffered request/response payload 6 MB 2 No Streamed response payload 20 MB No Background request/response payload 256 KB No - Sites created before October 4, 2023 may have a different default region. Check your current configuration in [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). - Requests with binary payloads such as image uploads are Base64-encoded, which adds approximately 30% overhead — effectively reducing the binary request payload size limit to 4.5 MB. Beyond these defaults, additional capabilities like [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity) can be enabled by [contacting your account manager](https://www.netlify.com/support/). By default, every function is available at `https:///.netlify/functions/`. Use the `path` property in the function's `config` to route it to one or more custom URLs. ``` import type { Config, Context } from "@netlify/functions"export default async (req: Request, context: Context) => { const { city, country } = context.params return new Response(`You're visiting ${city} in ${country}!`)}export const config: Config = { path: "/travel-guide/:city/:country",} ``` When you set a custom `path`, the function is only available at that path — not at the default `/.netlify/functions/` URL. To configure multiple paths, set `path` as an array. ``` export const config: Config = { path: ["/cats", "/dogs"],} ``` `path` supports the web platform [`URLPattern`](https://developer.mozilla.org/en-US/docs/Web/API/URL_Pattern_API) syntax for wildcards and named groups. Named groups are exposed to the function on `context.params`. ``` export const config: Config = { path: ["/sale/*", "/item/:sku"],} ``` Use `excludedPath` to carve exceptions out of a `path` pattern. Accepts a single string or an array of strings, each starting with `/`. ``` export const config: Config = { excludedPath: ["/product/*.css", "/product/*.js"], path: "/product/*",} ``` ### Prefer static files [Section titled “Prefer static files”](#prefer-static-files) By default, a function runs for any request to its configured paths regardless of whether static files exist there. To let static assets on the CDN win when they exist, set `preferStatic: true`. ``` export const config: Config = { path: ["/product/:sku", "/item/:sku"], preferStatic: true,} ``` By default, a function responds to every HTTP method. Use the `method` property to restrict it to specific methods. ``` export const config: Config = { method: ["GET", "POST"], path: "/items",} ``` This feature is available on all [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans. Netlify offers several regions for deploying your serverless functions. You may want to customize the region for the following reasons: - **Optimize performance.** Deploying serverless functions close to their data sources, such as a database or another backend service, can greatly reduce roundtrip time for data retrieval resulting in faster response times for your users. - **Ensure compliance.** In some cases, data protection laws and industry-specific regulations may require that sensitive data processing happens within specific regions. - **Use Private Connectivity.** Static IP addresses for [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity/) are available in only some regions. Regions are identified by airport code. By default, Netlify deploys functions for new sites to `cmh` (Ohio) — a common choice for many database providers, which optimizes performance for most cases. You can change the region through the Netlify UI to any of the following: Airport code Region `cmh` US East (Ohio) `dub` EU (Ireland) `fra` EU (Frankfurt) `gru` South America (São Paulo) `iad` US East (N. Virginia) `lhr` EU (London) `nrt` Asia Pacific (Tokyo) `pdx` US West (Oregon) `sfo` US West (N. California) `sin` Asia Pacific (Singapore) `syd` Asia Pacific (Sydney) `yul` Canada (Central) In addition to the above self-serve regions, the following are available through support-assisted configuration: Airport code Region `cdg` EU (Paris) `mxp` EU (Milan) If you want your site to use one of the above regions, please [contact support](https://www.netlify.com/support/). ### From the Netlify dashboard [Section titled “From the Netlify dashboard”](#from-the-netlify-dashboard) Setting the region through the Netlify UI applies to all functions on your site. 1. Go to [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). 2. Select **Configure**. 3. Use the menu to select a new region. 4. Confirm with **Save**. 5. Redeploy your site to apply the new region configuration. Old deploys will continue to use the region configuration from when they were deployed. If your project has functions that need to run in different regions — for example, one function that processes data close to a database in Dublin while the rest of your functions run in Ohio — you can override the region per function in code. The function-level region takes precedence over the site-level region set in the UI. With in-source configuration: ``` import type { Config } from "@netlify/functions"export default async (req: Request) => { return new Response("Hello from Europe!")}export const config: Config = { path: "/eu-data", region: "dub",} ``` With `netlify.toml`: ``` [functions.eu_data] region = "dub" ``` ### When to set a region [Section titled “When to set a region”](#when-to-set-a-region) The `cmh` (Ohio) default is a deliberate choice. US East is centrally located for an international audience, has a broad provider ecosystem and gives most projects the lowest overall latency without any configuration. Overriding it has tradeoffs, so leave the default in place unless one of these applies: - Your function talks to a database or backend service in another region, and you can measure the roundtrip savings. - You have a compliance or data-residency requirement that pins processing to a specific region. - Your audience is concentrated in one region and your compute dependencies (database, backend services) live in that same region. A few constraints to know before you reach for `config.region`: - Each function runs in exactly one region. You can't deploy the same function to multiple regions for geo-routing. - If your project uses a framework adapter (e.g., Tanstack Start, Astro, Next.js) the function files are generated at build time and you can't add `export const config` to them. Use the [project-level UI setting](#from-the-netlify-dashboard) instead, which applies to all functions in the project including the generated ones. This feature is available on Credit-based [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans only. By default, Netlify functions run with 1024 MB of memory and a proportional amount of compute. For workloads that need more resources to run reliably — such as processing large payloads or running AI inference — you can configure each function with either `memory` or `vcpu`. Memory and vCPU scale together: pick more of one and you get more of the other. Set whichever maps more naturally onto how you think about your function — megabytes when memory pressure is the constraint, vCPUs when you care about compute — and Netlify sizes the other side automatically. The two are mutually exclusive; set one, not both. With in-source configuration: ``` import type { Config } from "@netlify/functions"export default async (req: Request) => { return new Response("Doing more, faster")}export const config: Config = { memory: "2gb", // or memory: 2048 path: "/heavy",} ``` With `netlify.toml`: ``` [functions.heavy] memory = "2gb" ``` The `memory` property accepts either a number of megabytes or a human-friendly string with a unit (`"2gb"`, `"1024mb"`, case-insensitive). Allowed range: 1024 to 4096 MB. The `vcpu` property accepts a number between 0.5 and 2.0. The endpoints map to: - `vcpu: 0.5` → 1024 MB - `vcpu: 2.0` → 4096 MB Values in between scale linearly. ### When to set memory or vCPU [Section titled “When to set memory or vCPU”](#when-to-set-memory-or-vcpu) The 1024 MB default fits most functions, and raising it has a direct cost impact: function billing scales linearly with the configured size. Treat `memory` and `vcpu` as deliberate levers, reaching for them when: - You know the workload is memory- or compute-intensive — for example, local AI inference, image or PDF manipulation, large JSON or CSV processing, or anything CPU-bound. - You're hitting out-of-memory errors or timeouts caused by the function's own work, rather than by waiting on an external service or database. If you're unsure, start with the default and only tune after you have a measurement that justifies the change. For granular control over which files are bundled in your executable function artifacts, use the `netlify.toml` properties `external_node_modules` and `included_files`. Visit the [file-based configuration](https://docs.netlify.com/build/configure-builds/file-based-configuration/#functions) doc for details. ``` [functions] # Flags "package-1" as an external node module for all functions. external_node_modules = ["package-1"] # Includes all Markdown files inside the "files/" directory. included_files = ["files/*.md"] ``` ## Node.js version for runtime [Section titled “Node.js version for runtime”](#nodejs-version-for-runtime) For all Node.js functions deployed on or after May 15, 2023, the default functions runtime is based on the [Node.js version used for the build](https://docs.netlify.com/build/configure-builds/manage-dependencies/#node-js-and-javascript). The Node.js version used for the build must be a valid [AWS Lambda runtime for Node.js](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html) that isn't set to be deprecated in the next two months. If the build uses a version of Node.js that does not meet these conditions, then the functions runtime uses a fallback default version of Node.js 24. You can override the default to any valid [AWS Lambda runtime for Node.js](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html) that isn't set to be deprecated in the next two months. Do so by completing the following steps. 1. In the Netlify UI, [set the environment variable](https://docs.netlify.com/build/environment-variables/get-started/#create-variables-with-the-netlify-ui-cli-or-api) `AWS_LAMBDA_JS_RUNTIME` to the desired version. For example, to use Node.js 24 for all future functions deployed, set the variable value to `nodejs24.x`. 2. Redeploy your site to apply the new runtime version. Note that this environment variable must be set using the Netlify UI, CLI, or API, and not with a Netlify configuration file (`netlify.toml`). Node.js supports two distinct module formats with different capabilities and APIs: [ECMAScript modules](https://nodejs.org/api/esm.html) (or ES modules), an official standard format for JavaScript packages, and [CommonJS](https://nodejs.org/api/modules.html), a legacy format specific to Node.js. The module format for each function is determined by the file extension of its entry file: - Files with `.mts` or `.mjs` extensions are always executed as ES modules. - Files with `.cts` or `.cjs` extensions are always executed as CommonJS. - Files with `.ts` or `.js` extensions are executed as ES modules if the closest `package.json` has `"type": "module"`, otherwise as CommonJS. Choosing a module format has implications for how you import npm packages: - CommonJS functions cannot use a static `import` for npm packages written as ES modules; use a [dynamic import](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import) instead. - ES module functions cannot use named imports for npm packages written in CommonJS (for example, `import { kebabCase } from "lodash"`); use a default import (`import _ from "lodash"`). - In ES modules, Node.js built-ins like `__dirname` and `__filename` are not available; use [`import.meta.url`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import.meta) instead. ## Default values Unless customized, every function deploys with: Setting Default Configurable? Region `cmh` (US East, Ohio) 1 Yes — [Region](#region) Memory 1024 MB Yes — [Memory or vCPU](#memory-or-vcpu) Synchronous execution limit 60 seconds No Scheduled execution limit 30 seconds No Background execution limit 15 minutes No Buffered request/response payload 6 MB 2 No Streamed response payload 20 MB No Background request/response payload 256 KB No - Sites created before October 4, 2023 may have a different default region. Check your current configuration in [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). - Requests with binary payloads such as image uploads are Base64-encoded, which adds approximately 30% overhead — effectively reducing the binary request payload size limit to 4.5 MB. Beyond these defaults, additional capabilities like [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity) can be enabled by [contacting your account manager](https://www.netlify.com/support/). Netlify will access the functions directory during every build, preparing and deploying each supported code file as a function. The default directory is `YOUR_BASE_DIRECTORY/netlify/functions`. You can customize the directory using the Netlify UI or file-based configuration. - In the Netlify UI, go to [**Project configuration Build & deploy Continuous deployment Build settings**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#build-settings) and select **Configure**. In the **Functions directory** field, enter a path to the directory in your repository where you want to store your functions. ![](https://docs.netlify.com/images/functions-folder-setting.png) - Alternatively, add the following to `netlify.toml` for [file-based configuration](https://docs.netlify.com/build/configure-builds/file-based-configuration/). ``` [functions] directory = "my_functions" ``` Settings in `netlify.toml` override settings in the Netlify UI. For both methods, the path is an absolute path relative to the site's [base directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) in your repository. To help keep your site secure, make sure your functions directory is outside of your [publish directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) so that your source files aren't deployed as part of your site. By default, every function is available at `https:///.netlify/functions/`. Use the `path` property in the function's `config` to route it to one or more custom URLs. ``` export default async (req, context) => { const { city, country } = context.params return new Response(`You're visiting ${city} in ${country}!`)}export const config = { path: "/travel-guide/:city/:country",} ``` When you set a custom `path`, the function is only available at that path — not at the default `/.netlify/functions/` URL. To configure multiple paths, set `path` as an array. ``` export const config = { path: ["/cats", "/dogs"],} ``` `path` supports the web platform [`URLPattern`](https://developer.mozilla.org/en-US/docs/Web/API/URL_Pattern_API) syntax for wildcards and named groups. Named groups are exposed to the function on `context.params`. ``` export const config = { path: ["/sale/*", "/item/:sku"],} ``` Use `excludedPath` to carve exceptions out of a `path` pattern. Accepts a single string or an array of strings, each starting with `/`. ``` export const config = { excludedPath: ["/product/*.css", "/product/*.js"], path: "/product/*",} ``` ### Prefer static files [Section titled “Prefer static files”](#prefer-static-files-1) By default, a function runs for any request to its configured paths regardless of whether static files exist there. To let static assets on the CDN win when they exist, set `preferStatic: true`. ``` export const config = { path: ["/product/:sku", "/item/:sku"], preferStatic: true,} ``` By default, a function responds to every HTTP method. Use the `method` property to restrict it to specific methods. ``` export const config = { method: ["GET", "POST"], path: "/items",} ``` This feature is available on all [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans. Netlify offers several regions for deploying your serverless functions. You may want to customize the region for the following reasons: - **Optimize performance.** Deploying serverless functions close to their data sources, such as a database or another backend service, can greatly reduce roundtrip time for data retrieval resulting in faster response times for your users. - **Ensure compliance.** In some cases, data protection laws and industry-specific regulations may require that sensitive data processing happens within specific regions. - **Use Private Connectivity.** Static IP addresses for [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity/) are available in only some regions. Regions are identified by airport code. By default, Netlify deploys functions for new sites to `cmh` (Ohio) — a common choice for many database providers, which optimizes performance for most cases. You can change the region through the Netlify UI to any of the following: Airport code Region `cmh` US East (Ohio) `dub` EU (Ireland) `fra` EU (Frankfurt) `gru` South America (São Paulo) `iad` US East (N. Virginia) `lhr` EU (London) `nrt` Asia Pacific (Tokyo) `pdx` US West (Oregon) `sfo` US West (N. California) `sin` Asia Pacific (Singapore) `syd` Asia Pacific (Sydney) `yul` Canada (Central) In addition to the above self-serve regions, the following are available through support-assisted configuration: Airport code Region `cdg` EU (Paris) `mxp` EU (Milan) If you want your site to use one of the above regions, please [contact support](https://www.netlify.com/support/). Setting the region through the Netlify UI applies to all functions on your site. 1. Go to [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). 2. Select **Configure**. 3. Use the menu to select a new region. 4. Confirm with **Save**. 5. Redeploy your site to apply the new region configuration. Old deploys will continue to use the region configuration from when they were deployed. If your project has functions that need to run in different regions — for example, one function that processes data close to a database in Dublin while the rest of your functions run in Ohio — you can override the region per function in code. The function-level region takes precedence over the site-level region set in the UI. With in-source configuration: ``` export default async (req) => { return new Response("Hello from Europe!")}export const config = { path: "/eu-data", region: "dub",} ``` With `netlify.toml`: ``` [functions.eu_data] region = "dub" ``` ### When to set a region [Section titled “When to set a region”](#when-to-set-a-region-1) The `cmh` (Ohio) default is a deliberate choice. US East is centrally located for an international audience, has a broad provider ecosystem and gives most projects the lowest overall latency without any configuration. Overriding it has tradeoffs, so leave the default in place unless one of these applies: - Your function talks to a database or backend service in another region, and you can measure the roundtrip savings. - You have a compliance or data-residency requirement that pins processing to a specific region. - Your audience is concentrated in one region and your compute dependencies (database, backend services) live in that same region. A few constraints to know before you reach for `config.region`: - Each function runs in exactly one region. You can't deploy the same function to multiple regions for geo-routing. - If your project uses a framework adapter (e.g., Tanstack Start, Astro, Next.js) the function files are generated at build time and you can't add `export const config` to them. Use the [project-level UI setting](#from-the-netlify-dashboard) instead, which applies to all functions in the project including the generated ones. This feature is available on Credit-based [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans only. By default, Netlify functions run with 1024 MB of memory and a proportional amount of compute. For workloads that need more resources to run reliably — such as processing large payloads or running AI inference — you can configure each function with either `memory` or `vcpu`. Memory and vCPU scale together: pick more of one and you get more of the other. Set whichever maps more naturally onto how you think about your function — megabytes when memory pressure is the constraint, vCPUs when you care about compute — and Netlify sizes the other side automatically. The two are mutually exclusive; set one, not both. With in-source configuration: ``` export default async (req) => { return new Response("Doing more, faster")}export const config = { memory: "2gb", // or memory: 2048 path: "/heavy",} ``` With `netlify.toml`: ``` [functions.heavy] memory = "2gb" ``` The `memory` property accepts either a number of megabytes or a human-friendly string with a unit (`"2gb"`, `"1024mb"`, case-insensitive). Allowed range: 1024 to 4096 MB. The `vcpu` property accepts a number between 0.5 and 2.0. The endpoints map to: - `vcpu: 0.5` → 1024 MB - `vcpu: 2.0` → 4096 MB Values in between scale linearly. ### When to set memory or vCPU [Section titled “When to set memory or vCPU”](#when-to-set-memory-or-vcpu-1) The 1024 MB default fits most functions, and raising it has a direct cost impact: function billing scales linearly with the configured size. Treat `memory` and `vcpu` as deliberate levers, reaching for them when: - You know the workload is memory- or compute-intensive — for example, local AI inference, image or PDF manipulation, large JSON or CSV processing, or anything CPU-bound. - You're hitting out-of-memory errors or timeouts caused by the function's own work, rather than by waiting on an external service or database. If you're unsure, start with the default and only tune after you have a measurement that justifies the change. To optimize bundling time and artifact size, you can have Netlify use [esbuild](https://esbuild.github.io/) for bundling your JavaScript functions. Enable this in [`netlify.toml`](https://docs.netlify.com/build/configure-builds/file-based-configuration). ``` [functions] node_bundler = "esbuild" ``` For granular control over which files are bundled in your executable function artifacts, use the `netlify.toml` properties `external_node_modules` and `included_files`. Visit the [file-based configuration](https://docs.netlify.com/build/configure-builds/file-based-configuration/#functions) doc for details. ``` [functions] # Flags "package-1" as an external node module for all functions. external_node_modules = ["package-1"] # Includes all Markdown files inside the "files/" directory. included_files = ["files/*.md"] ``` ## Node.js version for runtime [Section titled “Node.js version for runtime”](#nodejs-version-for-runtime-1) For all Node.js functions deployed on or after May 15, 2023, the default functions runtime is based on the [Node.js version used for the build](https://docs.netlify.com/build/configure-builds/manage-dependencies/#node-js-and-javascript). The Node.js version used for the build must be a valid [AWS Lambda runtime for Node.js](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html) that isn't set to be deprecated in the next two months. If the build uses a version of Node.js that does not meet these conditions, then the functions runtime uses a fallback default version of Node.js 24. You can override the default to any valid [AWS Lambda runtime for Node.js](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html) that isn't set to be deprecated in the next two months. Do so by completing the following steps. 1. In the Netlify UI, [set the environment variable](https://docs.netlify.com/build/environment-variables/get-started/#create-variables-with-the-netlify-ui-cli-or-api) `AWS_LAMBDA_JS_RUNTIME` to the desired version. For example, to use Node.js 20 for all future functions deployed, set the variable value to `nodejs20.x`. 2. Redeploy your site to apply the new runtime version. Note that this environment variable must be set using the Netlify UI, CLI, or API, and not with a Netlify configuration file (`netlify.toml`). Node.js supports two distinct module formats with different capabilities and APIs: [ECMAScript modules](https://nodejs.org/api/esm.html) (or ES modules), an official standard format for JavaScript packages, and [CommonJS](https://nodejs.org/api/modules.html), a legacy format specific to Node.js. The module format for each function is determined by the file extension of its entry file: - Files with `.mts` or `.mjs` extensions are always executed as ES modules. - Files with `.cts` or `.cjs` extensions are always executed as CommonJS. - Files with `.ts` or `.js` extensions are executed as ES modules if the closest `package.json` has `"type": "module"`, otherwise as CommonJS. Choosing a module format has implications for how you import npm packages: - CommonJS functions cannot use a static `import` for npm packages written as ES modules; use a [dynamic import](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import) instead. - ES module functions cannot use named imports for npm packages written in CommonJS (for example, `import { kebabCase } from "lodash"`); use a default import (`import _ from "lodash"`). - In ES modules, Node.js built-ins like `__dirname` and `__filename` are not available; use [`import.meta.url`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/import.meta) instead. ## Default values Unless customized, every function deploys with: Setting Default Configurable? Region `cmh` (US East, Ohio) 1 Yes — [Region](#region) Memory 1024 MB Yes — [Memory or vCPU](#memory-or-vcpu) Synchronous execution limit 60 seconds No Scheduled execution limit 30 seconds No Background execution limit 15 minutes No Buffered request/response payload 6 MB 2 No Streamed response payload 20 MB No Background request/response payload 256 KB No - Sites created before October 4, 2023 may have a different default region. Check your current configuration in [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). - Requests with binary payloads such as image uploads are Base64-encoded, which adds approximately 30% overhead — effectively reducing the binary request payload size limit to 4.5 MB. Beyond these defaults, additional capabilities like [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity) can be enabled by [contacting your account manager](https://www.netlify.com/support/). Netlify will access the functions directory during every build, preparing and deploying each supported code file as a function. The default directory is `YOUR_BASE_DIRECTORY/netlify/functions`. You can customize the directory using the Netlify UI or file-based configuration. - In the Netlify UI, go to [**Project configuration Build & deploy Continuous deployment Build settings**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#build-settings) and select **Configure**. In the **Functions directory** field, enter a path to the directory in your repository where you want to store your functions. ![](https://docs.netlify.com/images/functions-folder-setting.png) - Alternatively, add the following to `netlify.toml` for [file-based configuration](https://docs.netlify.com/build/configure-builds/file-based-configuration/). ``` [functions] directory = "my_functions" ``` Settings in `netlify.toml` override settings in the Netlify UI. For both methods, the path is an absolute path relative to the site's [base directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) in your repository. To help keep your site secure, make sure your functions directory is outside of your [publish directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) so that your source files aren't deployed as part of your site. By default, every function is available at `https:///.netlify/functions/`. To route a function to a custom URL, configure it in `netlify.toml`. Routing for Go functions is configured exclusively via `netlify.toml`. ``` [[redirects]] from = "/travel-guide/*" to = "/.netlify/functions/travel-guide" status = 200 ``` For more advanced routing — wildcards, query parameters, language detection, role-based rules — see the [redirects documentation](https://docs.netlify.com/manage/routing/redirects/overview). This feature is available on all [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans. Netlify offers several regions for deploying your serverless functions. You may want to customize the region for the following reasons: - **Optimize performance.** Deploying serverless functions close to their data sources, such as a database or another backend service, can greatly reduce roundtrip time for data retrieval resulting in faster response times for your users. - **Ensure compliance.** In some cases, data protection laws and industry-specific regulations may require that sensitive data processing happens within specific regions. - **Use Private Connectivity.** Static IP addresses for [Private Connectivity](https://docs.netlify.com/manage/security/private-connectivity/) are available in only some regions. Regions are identified by airport code. By default, Netlify deploys functions for new sites to `cmh` (Ohio) — a common choice for many database providers, which optimizes performance for most cases. You can change the region through the Netlify UI to any of the following: Airport code Region `cmh` US East (Ohio) `dub` EU (Ireland) `fra` EU (Frankfurt) `gru` South America (São Paulo) `iad` US East (N. Virginia) `lhr` EU (London) `nrt` Asia Pacific (Tokyo) `pdx` US West (Oregon) `sfo` US West (N. California) `sin` Asia Pacific (Singapore) `syd` Asia Pacific (Sydney) `yul` Canada (Central) In addition to the above self-serve regions, the following are available through support-assisted configuration: Airport code Region `cdg` EU (Paris) `mxp` EU (Milan) If you want your site to use one of the above regions, please [contact support](https://www.netlify.com/support/). Setting the region through the Netlify UI applies to all functions on your site. 1. Go to [**Project configuration Build & deploy Continuous deployment Functions region**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#functions-region). 2. Select **Configure**. 3. Use the menu to select a new region. 4. Confirm with **Save**. 5. Redeploy your site to apply the new region configuration. Old deploys will continue to use the region configuration from when they were deployed. If your project has functions that need to run in different regions — for example, one function that processes data close to a database in Dublin while the rest of your functions run in Ohio — you can override the region per function in `netlify.toml`. The function-level region takes precedence over the site-level region set in the UI. ``` [functions.eu_data] region = "dub" ``` ### When to set a region [Section titled “When to set a region”](#when-to-set-a-region-2) The `cmh` (Ohio) default is a deliberate choice. US East is centrally located for an international audience, has a broad provider ecosystem and gives most projects the lowest overall latency without any configuration. Overriding it has tradeoffs, so leave the default in place unless one of these applies: - Your function talks to a database or backend service in another region, and you can measure the roundtrip savings. - You have a compliance or data-residency requirement that pins processing to a specific region. - Your audience is concentrated in one region and your compute dependencies (database, backend services) live in that same region. A few constraints to know before you reach for `region`: - Each function runs in exactly one region. You can't deploy the same function to multiple regions for geo-routing. - If your project uses a framework adapter (e.g., Tanstack Start, Astro, Next.js) the function files are generated at build time and you can't add `export const config` to them. Use the [project-level UI setting](#from-the-netlify-dashboard) instead, which applies to all functions in the project including the generated ones. This feature is available on Credit-based [Pro](https://www.netlify.com/pricing/?category=developer) and [Enterprise](https://www.netlify.com/pricing/?category=enterprise) plans only. By default, Netlify functions run with 1024 MB of memory and a proportional amount of compute. For workloads that need more resources to run reliably — such as processing large payloads or running AI inference — you can configure each function with either `memory` or `vcpu`. Memory and vCPU scale together: pick more of one and you get more of the other. Set whichever maps more naturally onto how you think about your function — megabytes when memory pressure is the constraint, vCPUs when you care about compute — and Netlify sizes the other side automatically. The two are mutually exclusive; set one, not both. Configure per-function resources in `netlify.toml`: ``` [functions.heavy] memory = "2gb" # or: vcpu = 1.5 ``` The `memory` property accepts either a number of megabytes or a human-friendly string with a unit (`"2gb"`, `"1024mb"`, case-insensitive). Allowed range: 1024 to 4096 MB. The `vcpu` property accepts a number between 0.5 and 2.0. The endpoints map to: - `vcpu: 0.5` → 1024 MB - `vcpu: 2.0` → 4096 MB Values in between scale linearly. ### When to set memory or vCPU [Section titled “When to set memory or vCPU”](#when-to-set-memory-or-vcpu-2) The 1024 MB default fits most functions, and raising it has a direct cost impact: function billing scales linearly with the configured size. Treat `memory` and `vcpu` as deliberate levers, reaching for them when: - You know the workload is memory- or compute-intensive — for example, local AI inference, image or PDF manipulation, large JSON or CSV processing, or anything CPU-bound. - You're hitting out-of-memory errors or timeouts caused by the function's own work, rather than by waiting on an external service or database. If you're unsure, start with the default and only tune after you have a measurement that justifies the change. ## Go version for builds [Section titled “Go version for builds”](#go-version-for-builds) The Go version used in the deployment pipeline is determined by your site's [build image](https://docs.netlify.com/build/configure-builds/overview#build-image-selection). To modify the Go version used for your builds, change the build image for your site at [**Project configuration Build & deploy Continuous Deployment Build image selection**](https://app.netlify.com/projects/%7Bsite_name%7D/configuration/deploys#build-image-selection). Netlify will access the functions directory during every build, preparing and deploying each supported code file as a function. The default directory is `YOUR_BASE_DIRECTORY/netlify/functions`. You can customize the directory using the Netlify UI or file-based configuration. Settings in `netlify.toml` override settings in the Netlify UI. For both methods, the path is an absolute path relative to the site's [base directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) in your repository. To help keep your site secure, make sure your functions directory is outside of your [publish directory](https://docs.netlify.com/build/configure-builds/overview/#definitions-1) so that your source files aren't deployed as part of your site.