High-quality APIs for Deno and the web. Use fearlessly.

NOTE: The standard library is also available on JSR - check out the @std scope on JSR here.

import { copy } from "https://deno.land/std@$STD_VERSION/fs/copy.ts";

await copy("./foo", "./bar");

See here for recommended usage patterns.

Check out the documentation here.

1. Include the version of the library in the import specifier.

   Good:

   import { copy } from "https://deno.land/std@$STD_VERSION/fs/copy.ts";

2. Only import modules that you require.

   Bad (when using only one function):

   import * as fs from "https://deno.land/std@$STD_VERSION/fs/mod.ts";

   Good (when using only one function):

   import { copy } from "https://deno.land/std@$STD_VERSION/fs/copy.ts";

   Good (when using multiple functions):

   import * as fs from "https://deno.land/std@$STD_VERSION/fs/mod.ts";

3. Do not import symbols with a name prefixed by an underscore (they're not intended for public use).

   Bad:

   import { _format } from "https://deno.land/std@$STD_VERSION/path/_common/format.ts";

4. Do not import modules with a directory or filename prefixed by an underscore (they're not intended for public use).

   Bad:

   import { createLPS } from "https://deno.land/std@$STD_VERSION/streams/_common.ts";

   Good:

   import { TextLineStream } from "https://deno.land/std@$STD_VERSION/streams/text_line_stream.ts";

5. Do not import test modules or test data.

   Bad:

   import { test } from "https://deno.land/std@$STD_VERSION/front_matter/test.ts";

For background and discussions regarding the stability of the following sub-modules, see #3489.

Check out the architecture guide here.

Files are structured to minimize the number of dependencies they incur and the amount of effort required to manage them, both for the maintainer and the user. In most cases, only a single function or class, alongside its related types, are exported. In other cases, functions that incur negligible dependency overhead will be grouped together in the same file.

We deprecate the APIs in the Standard Library when they get covered by new JavaScript language APIs or new Web Standard APIs. These APIs are usually removed after 3 minor versions.

If you still need to use such APIs after the removal for some reason (for example, the usage in Fresh island), please use the URL pinned to the version where they are still available.

For example, if you want to keep using readableStreamFromIterable, which was deprecated and removed in favor of ReadableStream.from in v0.195.0, please use the import URL pinned to v0.194.0:

import { readableStreamFromIterable } from "https://deno.land/[email protected]/streams/readable_stream_from_iterable.ts";

Check out the contributing guidelines here.

The Standard Library is versioned independently of the Deno CLI. This will change once the Standard Library is stabilized. See here for the compatibility of different versions of the Deno Standard Library and the Deno CLI.

A new minor version of the Standard Library is published at the same time as every new version of the Deno CLI (including patch versions).

<a href="https://deno.land/std">
  <img
    width="135"
    height="20"
    src="https://raw.githubusercontent.com/denoland/deno_std/main/badge.svg"
    alt="Built with the Deno Standard Library"
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</a>

[![Built with the Deno Standard Library](https://raw.githubusercontent.com/denoland/deno_std/main/badge.svg)](https://deno.land/std)