内置的processmodule有一个方法memoryUsage可以洞察当前 Node.js 进程的内存使用情况。以下是 64 位系统上 Node v0.12.2 中的示例：

$ node --expose-gc
> process.memoryUsage();  // Initial usage
{ rss: 19853312, heapTotal: 9751808, heapUsed: 4535648 }
> gc();                   // Force a GC for the baseline.
undefined
> process.memoryUsage();  // Baseline memory usage.
{ rss: 22269952, heapTotal: 11803648, heapUsed: 4530208 }
> var a = new Array(1e7); // Allocate memory for 10m items in an array
undefined
> process.memoryUsage();  // Memory after allocating so many items
{ rss: 102535168, heapTotal: 91823104, heapUsed: 85246576 }
> a = null;               // Allow the array to be garbage-collected
null
> gc();                   // Force GC (requires node --expose-gc)
undefined
> process.memoryUsage();  // Memory usage after GC
{ rss: 23293952, heapTotal: 11803648, heapUsed: 4528072 }
> process.memoryUsage();  // Memory usage after idling
{ rss: 23293952, heapTotal: 11803648, heapUsed: 4753376 }

在这个简单的示例中，您可以看到分配一个 10M 元素的数组消费者大约 80MB（看看heapUsed）。
如果您查看 V8 的源代码（Array::New, Heap::AllocateRawFixedArray, FixedArray::SizeFor），那么您会看到数组使用的内存是一个固定值加上长度乘以指针大小。后者是 64 位系统上的 8 个字节，这证实了观察到的 8 x 10 = 80MB 内存差异是有道理的。

node-memwatch：检测和查找 Node.JS 代码中的内存泄漏。检查本教程跟踪 Node.js 中的内存泄漏

另外，如果您想知道全局内存而不是节点进程'：

var os = require('os');

os.freemem();
os.totalmem();

查看文档

最初的memwatch基本上已经死了。试试memwatch-next，它似乎在现代版本的Node.js上运行良好。

您可以使用 node.js memoryUsage

const formatMemoryUsage = (data) => `${Math.round(data / 1024 / 1024 * 100) / 100} MB`

const memoryData = process.memoryUsage()

const memoryUsage = {
                rss: `${formatMemoryUsage(memoryData.rss)} -> Resident Set Size - total memory allocated for the process execution`,
                heapTotal: `${formatMemoryUsage(memoryData.heapTotal)} -> total size of the allocated heap`,
                heapUsed: `${formatMemoryUsage(memoryData.heapUsed)} -> actual memory used during the execution`,
                external: `${formatMemoryUsage(memoryData.external)} -> V8 external memory`,
}

console.log(memoryUsage)
/*
{
    "rss": "177.54 MB -> Resident Set Size - total memory allocated for the process execution",
    "heapTotal": "102.3 MB -> total size of the allocated heap",
    "heapUsed": "94.3 MB -> actual memory used during the execution",
    "external": "3.03 MB -> V8 external memory"
}
*/