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Usage Jump to heading

Run a local file:

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deno run main.ts

The run subcommand is optional — you can also just use deno <file>:

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deno main.ts

By default, Deno runs programs in a sandbox without access to disk, network or ability to spawn subprocesses. This is because the Deno runtime is secure by default. You can grant or deny required permissions using the --allow-* and --deny-* flags.

Permissions examples Jump to heading

Grant permission to read from disk and listen to network:

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deno run --allow-read --allow-net server.ts

Grant permission to read allow-listed files from disk:

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deno run --allow-read=/etc server.ts

Grant all permissions this is not recommended and should only be used for testing:

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deno run -A server.ts

If your project requires multiple security flags you should consider using a deno task to execute them.

Watch Jump to heading

To watch for file changes and restart process automatically use the --watch flag. Deno's built in application watcher will restart your application as soon as files are changed.

Be sure to put the flag before the file name eg:

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deno run --allow-net --watch server.ts

Deno's watcher will notify you of changes in the console, and will warn in the console if there are errors while you work.

The same --watch flag is also accepted by deno test, deno serve, and deno bench.

Deno 2.8

When the watcher restarts the process, Deno sends SIGTERM first so unload event listeners and process.exit hooks run, then waits 500ms before the hard kill. This gives graceful-shutdown code time to flush resources between restarts.

Running a package.json script Jump to heading

package.json scripts can be executed with the deno task command.

Running code from stdin Jump to heading

You can pipe code from stdin and run it immediately:

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echo "console.log('hello')" | deno run -

Terminate run Jump to heading

To stop the run command use ctrl + c.

Command line usage:
run

Run a JavaScript or TypeScript program, or a task

Options Jump to heading

--allow-scripts
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Allow running npm lifecycle scripts for the given packages Note: Scripts will only be executed when using a node_modules directory (--node-modules-dir).

--cached-only
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Require that remote dependencies are already cached.

Load certificate authority from PEM encoded file.

Enable type-checking. This subcommand does not type-check by default; pass --check=all to also type-check remote modules. Alternatively, use the 'deno check' subcommand.

Use this argument to specify custom conditions for npm package exports. You can also use DENO_CONDITIONS env var. .

Configure different aspects of deno including TypeScript, linting, and code formatting. Typically the configuration file will be called deno.json or deno.jsonc and automatically detected; in that case this flag is not necessary.

Collect coverage profile data into DIR. If DIR is not specified, it uses 'coverage/'. This option can also be set via the DENO_COVERAGE_DIR environment variable.

Load environment variables from local file Only the first environment variable with a given key is used. Existing process environment variables are not overwritten, so if variables with the same names already exist in the environment, their values will be preserved. Where multiple declarations for the same environment variable exist in your .env file, the first one encountered is applied. This is determined by the order of the files you pass as arguments.

Set content type of the supplied file.

--frozen-lockfile
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Error out if lockfile is out of date.

Watch for file changes and hot-replace modules. The process restarts if hot replacement fails. Local files from entry point module graph are watched by default. Additional paths might be watched by passing them as arguments to this flag.

Load import map file from local file or remote URL.

Activate inspector on host:port [default: 127.0.0.1:9229]. Host and port are optional. Using port 0 will assign a random free port.

--inspect-brk
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Activate inspector on host:port, wait for debugger to connect and break at the start of user script.

--inspect-publish-uid
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--inspect-wait
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Activate inspector on host:port and wait for debugger to connect before running user code.

Value of globalThis.location used by some web APIs.

Check the specified lock file. (If value is not provided, defaults to "./deno.lock").

--min-dep-age
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(Unstable) The age in minutes, ISO-8601 duration or RFC3339 absolute timestamp (e.g. '120' for two hours, 'P2D' for two days, '2025-09-16' for cutoff date, '2025-09-16T12:00:00+00:00' for cutoff time, '0' to disable).

Skip type-checking. If the value of "remote" is supplied, diagnostic errors from remote modules will be ignored.

--no-clear-screen
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Do not clear terminal screen when under watch mode.

--no-code-cache
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Disable V8 code cache feature.

--no-config
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Disable automatic loading of the configuration file.

Disable auto discovery of the lock file.

Do not resolve npm modules.

--no-remote
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Do not resolve remote modules.

--node-modules-dir
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Selects the node_modules directory mode for npm packages (not a path). One of: auto (create a local node_modules directory and install npm packages into it), manual (use the existing local node_modules directory, do not modify it), none (do not use a local node_modules directory; resolve npm packages from the global cache). Defaults to auto when the flag is passed without a value.

--node-modules-linker
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Sets the linker mode for npm packages (isolated or hoisted).

A list of files that will be executed before the main module.

--reload, -r
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Reload source code cache (recompile TypeScript). With no value, reloads everything. Pass a comma-separated list of specifiers to reload only those modules; npm: reloads all npm modules; npm:chalk reloads a single npm module; jsr:@std/http/file-server,jsr:@std/assert/assert-equals reloads specific modules.

A list of CommonJS modules that will be executed before the main module.

Set the random number generator seed.

--unsafely-ignore-certificate-errors
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DANGER: Disables verification of TLS certificates.

--use-env-proxy
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Use HTTP_PROXY, HTTPS_PROXY, and NO_PROXY for node:http/node:https.

To see a list of all available flags use --v8-flags=--help Flags can also be set via the DENO_V8_FLAGS environment variable. Any flags set with this flag are appended after the DENO_V8_FLAGS environment variable.

Toggles local vendor folder usage for remote modules and a node_modules folder for npm packages.

Watch for file changes and restart process automatically. Local files from entry point module graph are watched by default. Additional paths might be watched by passing them as arguments to this flag.

--watch-exclude
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Exclude provided files/patterns from watch mode.

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