diff --git a/README.md b/README.md
index 8d82f17..5480ba3 100644
--- a/README.md
+++ b/README.md
@@ -1,14 +1,16 @@
 # nrm-lite
 
-[![npm](https://img.shields.io/npm/v/nrm-lite)](https://www.npmjs.com/package/nrm-lite)  [![install size](https://packagephobia.com/badge?p=nrm-lite)](https://packagephobia.com/result?p=nrm-lite)
+[![npm](https://img.shields.io/npm/v/nrm-lite)](https://www.npmjs.com/package/nrm-lite)
+[![node-current](https://img.shields.io/node/v/nrm-lite)](https://nodejs.dev/)
+[![install size](https://packagephobia.com/badge?p=nrm-lite)](https://packagephobia.com/result?p=nrm-lite)
 
-Simple and lightweight replacement for nrm.  
-Like [dnrm](https://github.com/markthree/dnrm), but in pure Node.js
+Fast and lightweight NpmRegistryManager, for the minimalists.  
+Like [dnrm](https://github.com/markthree/dnrm), but in pure Node.js.
 
 ## Features
 
 -   Super lightweight, pure Node.js with NO dependency
--   Fast, DO NOT parse the `.npmrc` file (slightly slower that `dnrm`, due to the runtime)
+-   Fast, DO NOT parse the `.npmrc` file
 -   Correct, follow the rules of the `.npmrc` file
 
 ## Install
@@ -26,17 +28,28 @@ nrml use taobao
 nrml test
 ```
 
+It is well-known that [Deno](https://deno.com/)'s cold start is faster than Node.js.  
+Hence you can install `nrm-lite` in deno, so it will be as fast as `dnrm`.
+
+```sh
+# install `nrml` in deno
+deno install -Arf npm:nrm-lite -n nrml
+
+# test if it's installed
+nrml --help
+```
+
 ## Usage
 
 ```sh
 nrm-lite
 
 Usage:
-    nrml ls                List registry
+    nrml ls                List registries
     nrml use  <name>       Use registry
     nrml test [<timeout>]  Test registry speed, optional timeout in second (default: 2)
     nrml rc                Open .npmrc file
     nrml help              Show this help
 Global Options:
-    --local            Use local .npmrc file, rather than the global one (default: false)
+    --local                Use local .npmrc file, rather than the global one (default: false)
 ```
diff --git a/cli.mjs b/cli.mjs
index d437c20..81da6c1 100644
--- a/cli.mjs
+++ b/cli.mjs
@@ -37,7 +37,7 @@ if (values.help) {
     help()
 }
 
-const command = positionals[0] || 'ls'
+const command = positionals[0] || ''
 const { local } = values
 /**
  * @type {string}
@@ -53,6 +53,9 @@ switch (command) {
     case 'help':
         help()
         break
+    // @ts-ignore intentional fallthrough here
+    case '':
+        if (values.version) help(true)
     case 'ls':
         ls()
         break
@@ -72,16 +75,23 @@ switch (command) {
         process.exit(1)
 }
 
-function help() {
+/**
+ * @param {boolean=} v - only print version number
+ */
+function help(v) {
     // assert json will cause ExperimentalWarning. so we use this instead
     // import pkg from './package.json' assert { type: 'json' }
     const __filename = fileURLToPath(import.meta.url)
     const __dirname = dirname(__filename)
     const pkg = JSON.parse(readFileSync(`${__dirname}/package.json`, 'utf-8'))
+    if (v) {
+        console.error('v' + pkg.version)
+        process.exit(1)
+    }
     console.error(`${c.green(pkg.name)} v${pkg.version}
 
 ${c.bold('Usage:')}
-    nrml ls                List registry
+    nrml ls                List registries
     nrml use  ${c.gray('<name>')}       Use registry
     nrml test ${c.gray(
         '[<timeout>]'
@@ -89,7 +99,7 @@ ${c.bold('Usage:')}
     nrml rc                Open .npmrc file
     nrml help              Show this help
 ${c.bold('Global Options:')}
-    --local            Use local .npmrc file, rather than the global one (default: false)`)
+    --local                Use local .npmrc file, rather than the global one (default: false)`)
     process.exit(1)
 }
 
diff --git a/package.json b/package.json
index fa03082..f5a5519 100644
--- a/package.json
+++ b/package.json
@@ -1,9 +1,10 @@
 {
     "name": "nrm-lite",
-    "version": "0.1.2",
+    "version": "0.1.3",
     "type": "module",
-    "description": "simple and lightweight replacement for nrm",
+    "description": "Fast and lightweight NpmRegistryManager, for the minimalists.",
     "main": "index.mjs",
+    "sideEffects": false,
     "scripts": {
         "test": "node --test",
         "watch": "tsc --watch",
@@ -21,7 +22,7 @@
         "nrml": "cli.mjs"
     },
     "devDependencies": {
-        "@types/node": "^20.11.25",
+        "@types/node": "^20.11.26",
         "typescript": "^5.4.2"
     },
     "publishConfig": {
diff --git a/registry.mjs b/registry.mjs
index 838bb27..217ab19 100644
--- a/registry.mjs
+++ b/registry.mjs
@@ -1,7 +1,7 @@
 import * as readline from 'node:readline'
 
 /**
- * @type { Record<string,string>}
+ * @type {Record<string,string>}
  */
 export const REGISTRIES = {
     npm: 'https://registry.npmjs.org/',
@@ -17,8 +17,8 @@ export const REGISTRIES = {
  * Note that `registryLineNumber` is index + 1
  *
  * @param {NodeJS.ReadableStream} stream
- * @returns {Promise<{registry:string,lines:string[],registryLineNumber:number}|
- *                   {registry:null,lines:string[],registryLineNumber:null}>}
+ * @returns {Promise<{registry:string,lines:string[],registryLineNumber:number}
+ *                  |{registry:null,lines:string[],registryLineNumber:null}>}
  * @see https://docs.npmjs.com/cli/configuring-npm/npmrc
  *
  * @example
@@ -49,6 +49,7 @@ export async function findRegistryFromStream(stream) {
 }
 
 /**
+ * Returns `Infinity` when execeed timeout, and `null` when network error
  * @param {string} url
  * @param {number} timeoutLimit - in milliseconds
  */
@@ -60,7 +61,7 @@ export async function speedTest(url, timeoutLimit) {
             signal: AbortSignal.timeout(timeoutLimit),
         })
         const timeSpent = Date.now() - beginTime
-        return timeSpent
+        return timeSpent > timeoutLimit ? Infinity : timeSpent
     } catch (e) {
         if (e instanceof DOMException) {
             return Infinity
diff --git a/tty.mjs b/tty.mjs
index 64b0a88..1713243 100644
--- a/tty.mjs
+++ b/tty.mjs
@@ -1,4 +1,4 @@
-import { REGISTRIES, speedTest } from './registry.mjs'
+import { REGISTRIES } from './registry.mjs'
 
 /**
  * @param {string} str