# llGetUsedMemory

*LSL function*

```lsl
integer integer llGetUsedMemory();
```

- Returns: `integer`
- Energy: 10

Returns an integer representing the total number of bytes of memory currently used by the script (non-Mono scripts always return 16,384 bytes).

```lsl title="How to use" frame="terminal"
integer result = llGetUsedMemory();
```

## Specification

This function's behavior is dependent upon the VM the script is using. [Mono](#mono) is the new VM, [LSO](#lso) is the old VM. The big difference between Mono and LSO is that Mono scripts run faster and can utilize four times more memory.

### Mono

In Mono the value returned is the amount of memory currently in use by the script. This is achieved by searching the script's stack and counting all reachable resources. In terms of garbage collection, memory that hasn't been GC'd doesn't count against the script's memory limit when it's no longer reachable.[^wiki-678c2a]

The reason why Mono/[SLua](https://wiki.secondlife.com/wiki/SLua_Alpha) implements its memory limits this way is because there's a single VM/GC governing their scripts, and you don't want to "stop the world" to run the garbage collector just to see if you can get a single script back under its limit.

### LSO

LSO scripts always use 16KiB of memory.

[^wiki-678c2a]: Explanation given by Harold Linden in the official Discord server.

## Caveats

- Scripts compiled to LSO always report 16KB memory used.
- This can be called at any time and does **not** require [llScriptProfiler](/functions/llScriptProfiler/)

## Examples

<details open>
<summary>Calling `llGetUsedMemory` can look like this:</summary>

```lsl
integer used_memory = llGetUsedMemory();
llOwnerSay((string)used_memory + " bytes of memory currently used.");
```

</details>

## Notes

The amount of used memory is updated only at the start of a server frame, meaning the values from this function can fluctuate. To ensure stable values, it's possible to wait until the next frame, e.g. [llSleep](/functions/llSleep/)(0.01) before the call to `llGetUsedMemory`.

## History

Date of Release [17/06/2011](https://wiki.secondlife.com/wiki/Release_Notes/Second_Life_Server/11#11-06-17-233176)

## See also

### Functions

- [llGetFreeMemory](/functions/llGetFreeMemory/)
- [llSetMemoryLimit](/functions/llSetMemoryLimit/)
- [llScriptProfiler](/functions/llScriptProfiler/)

---

*Source: [LlGetUsedMemory](https://wiki.secondlife.com/wiki/LlGetUsedMemory) on the Second Life Wiki. Content from the Second Life Wiki article LlGetUsedMemory (revision 1218635, 2026-02-18), CC BY-SA 3.0.*

---

From lsl.dev: https://lsl.dev/functions/llGetUsedMemory/