HomeRuntimesLM Studio

Runtime sheet

LM Studio

Version in force 0.4.21-22026-08-12Tree audited closed source: no tree to auditLicence Proprietary

For anyone who does not want a command line and would rather see the models and the settings on screen.

A desktop application with a full graphical interface: search for models, download them, chat, and start an OpenAI-compatible server without ever opening a terminal.

At a glance
Version and release pace0.4.21-2
Which address it listens on127.0.0.1:1234
Steps to the first token3 steps
Hosts it contacts out of the box5
LicenceProprietary
3

Steps to the first token

Vendor declared

5

Hosts it contacts out of the box

Vendor declared

Proprietary

Licence

Measured by Local AI Scope

Method

How we checked this

Everything this sheet says about the network comes from reading the published source code and the official documentation on the date shown — not from watching the traffic. We have not run the program with a network analyser in front of it, so this is static analysis, not observation. A real capture is still pending; the day we have one, these cells move up a level of evidence. We would rather say that than let you assume we sniffed the wire.

Outbound

What leaves your machine

The four questions a local runtime has to answer before it deserves your documents: what it sends on its own, who else it calls, on which address it listens, and whether you can check any of it yourself.

Telemetry out of the box

It states that it has none — and it is the only one of the five where nobody outside can check. Vendor declared, not independently verified

This is the tension at the heart of this comparison. LM Studio says in its privacy policy that the application contains no telemetry. We are not saying they are lying; we are saying the source is closed and their own terms forbid reverse engineering, so nobody outside the company can verify it. Four of the five rows in our table say verified; this one says vendor’s word. The definition is also narrow: the same policy admits that every update check sends app version and build, operating system and IP address, with the declared purpose of understanding the spread of their user base, and that they receive model search queries.

«Because the application does not include telemetry or user-specific tracking, we are unable to fulfill data subject requests such as providing a copy of your data or deleting your information.»

How to switch it off: Not applicable, according to the vendor: there is no documented telemetry switch, because in their account there is no telemetry to switch off.

Source · consulted 2026-08-25

Other calls home

Every call this program makes on its own: what, where to, when and whether you can avoid it
What Where to When Can you avoid it Evidence
Model search and download huggingface.co Whenever you use the Discover tab. Their policy adds that they receive anonymised search queries. Do not use it vendor declared
Download and auto-update of the inference engines LM Studio infrastructure When checking for or installing engines. There is an auto-update setting, but its location is not documented vendor declared
LM Studio Hub — presets and publishing lmstudio.ai Only while signed in. Do not sign in vendor declared
LM Studio Cloud and web search LM Studio infrastructure and its providers Only if you buy the cloud features and use them; web search requires signing in. Do not buy them vendor declared
LM Link — sharing models between your own machines end-to-end encrypted network over Tailscale, discovery through the Hub Only if you turn it on. End-to-end encrypted over Tailscale, discovery through the Hub. Yes, a setting turns it off vendor declared

«Device and app information (app version and build, operating system) and IP address (included automatically by our CDN provider). […] to give us an understanding of the software and hardware spread of our user-base.»

Source · consulted 2026-08-25

Which address it listens on

The address, the authentication and the CORS policy this program ships with
Setting Out of the box
Listens on 127.0.0.1:1234
Authentication out of the box none
CORS out of the box Disabled — the only one of the five that ships with CORS off

Here is the twist that makes this table worth building: the one you cannot audit is the best configured out of the box. It listens on localhost only, it is the only one of the five that ships with CORS disabled, and it is the only one with an API-key system with scoped permissions. Its own network-serving page warns that any bind other than 127.0.0.1 exposes the server beyond localhost and recommends turning authentication on. Vendor declared, not independently verified

Source · consulted 2026-08-25

Can this be audited?

No. The application is closed source and its terms — the version dated 23 August 2026 — describe the code as a trade secret and expressly forbid reverse engineering, decompiling or disassembling it. Some pieces around it are open and MIT: the `lms` command line, the TypeScript and Python SDKs, the MLX engine and venvstacks. The program itself is not. That is why every telemetry claim on this sheet is the vendor’s word rather than a fact — not because we think it is false, but because there is no way to check. Verified by us in the primary source

«reverse engineer, decompile, disassemble, or otherwise attempt to derive the source code for the Software»

Source · consulted 2026-08-25

Privacy policy

Element Labs, Inc. (Delaware), policy dated June 2026. It states that if you download and run models locally, none of your messages, chat histories or documents ever leave your system. The Hub has its own, separate policy, which does collect email, profile name, IP address, browser type and actions taken. vendor declared Source

Coverage

What it runs, and where

Platforms, accelerators and model formats — the three walls you hit on the first evening, and the ones nobody writes down until you have hit them.

Where it runs

Platform support, one row per platform
Platform Support Evidence
Windows Yes: x64 and ARM64 (Snapdragon X Elite). On x64 it requires the AVX2 instruction set. verified by us
macOS Apple Silicon Yes: macOS 14.0 or newer; they recommend 16 GB of memory or more. vendor declared
macOS Intel No. The documentation says Intel Macs are not supported, and their own download service returns HTTP 400 for darwin/x64 while darwin/arm64 serves the .dmg. verified by us
Linux Yes, as an AppImage only, x64 and ARM64, Ubuntu 20.04 or newer. No .deb, no .rpm. verified by us

What it accelerates

Hardware acceleration backends and their status
Backend Status Evidence
CUDA Yes, via a llama.cpp engine built with CUDA. vendor declared
ROCm Yes, via a llama.cpp engine with ROCm. vendor declared
Metal Yes: Metal through llama.cpp, plus its own MLX engine on Apple Silicon — and that engine is public and MIT. vendor declared
Vulkan Yes, via a llama.cpp engine with Vulkan. vendor declared
CPU Yes. On x64 it requires AVX2. vendor declared
NPU We could not verify this. No primary source mentions NPU support one way or the other, so we make no claim. not verified

Model formats it runs

GGUF and MLX. Its catalogue format abstracts both away. Whether it takes unconverted safetensors is not something we could verify. vendor declared

Source · consulted 2026-08-25

Living with it

Installing it, and living with it

How many steps to the first token, what it leaves on your disk, under which licence and at what pace it changes under you.

Steps to the first token

3 steps. Three steps inside the application: search in the Discover tab, download, load and chat. No terminal at any point. vendor declared

What it writes to your disk

What this program writes to your disk and where
What Where Evidence
Models ~/.lmstudio/models/<publisher>/<model>/ — the directory is configurable vendor declared
Chat history, in plain JSON files ~/.lmstudio/conversations/ vendor declared
Local server logs and Hub presets ~/.lmstudio/server-logs/ · ~/.lmstudio/hub/ vendor declared

Licence

Proprietary (EULA). Free for personal use and for internal business use since July 2025 — but you may not resell it as a service: the terms forbid service-bureau use, application service providers and software-as-a-service. verified by us

Source · consulted 2026-08-25

Version and release pace

Two to three releases a month: ten versions in four months, from 0.4.12 in April 2026 to 0.4.21 in August. Its sibling Bionic moves far faster — ten versions in 33 days. vendor declared

Source · consulted 2026-08-25

Warnings

What to know before you install it

  • It is the only one of the five whose network behaviour cannot be checked: closed source, and reverse engineering forbidden by contract. Its promise of no telemetry may well be true, but it is the vendor’s word, not a verifiable fact.
  • Its own policy admits that every update check sends app version and build, operating system and IP address, and that they receive model search queries. We found no documented switch to stop that check.
  • It is, on the other hand, the best locked down out of the box in everything that is configurable: localhost only, CORS off, and API keys with permissions.
  • Careful with the marketing: the free plan card on their pricing page says «No data ever leaves your device» and, in the same card, lists a web search tool with the footnote «when logged in» — a tool that by definition sends the query out. Not a lie; imprecise.
  • The product has forked: since July 2026 LM Studio Bionic is a separate application, Windows x64 and macOS ARM64 only. When somebody says «LM Studio» today, they may mean two different programs. This sheet is about LM Studio 0.4.21.