Importmeta

importmeta is a meta-property exposed by the JavaScript module system for ECMAScript modules (ESM). It provides metadata about the currently executing module and is accessible only from within modules. The exact shape of import.meta depends on the host environment, but its purpose is to give module authors a way to learn about and work with their module’s context.

The most widely standardized property of import.meta is import.meta.url. This field contains the fully resolved URL of the module. In browsers, a module loaded with type="module" yields a URL corresponding to where the module was fetched from. In Node.js with ESM, import.meta.url is a file URL pointing to the module’s location on disk. Developers commonly use import.meta.url as a base for resolving relative resources, for example by creating new URLs with new URL('./data.json', import.meta.url).

Beyond url, some environments expose additional, experimental, or proposal-stage facilities such as import.meta.resolve, which would resolve a specifier relative to the current module. Support for such features is not universal and should be verified for the target runtime.

Import.meta is typically considered a read-only source of metadata; the object itself reflects the environment and is not intended to be reassigned or heavily mutated by user code. However, because its contents can vary by platform, code that relies on import.meta should guard against cross-environment differences.

In summary, import.meta is a lightweight mechanism for modules to access context-related information, with import.meta.url being the most reliable and widely supported property across modern browsers and Node.js.