The short answer
Cursor runs the model on Cursor’s servers. Onyx Code runs the model on your machine. Nearly every other difference between the two follows from that one.
Pick Cursor when
You want the strongest frontier models doing the reasoning, you are happy for your code to reach a cloud service to get there, and a monthly subscription is fine.
Pick Onyx Code when
Your code is not allowed to leave the machine, you work offline or on a restricted network, or you want the AI to keep working with no account and no subscription.
Either is fine when
You are working on a hobby project on a normal laptop with normal internet. At that point this is a preference, not a decision, and Cursor’s models are better at hard problems.
The one real difference: where the model runs
Cursor is a cloud product with an editor attached. Your prompt, the surrounding code and the retrieved context are sent to Cursor, which calls a model provider and streams the answer back. That is what makes its frontier models feel as good as they do, and it is also what makes the question of what leaves your machine unavoidable.
Onyx Code ships a llama.cpp inference engine inside the app and a model tuned to your hardware. Chat, autocomplete, next-edit prediction, codebase search and the agent all run against that engine on localhost. There is no account, no sign-in and no server to configure, and you can pull the network cable mid-completion.
localhost is not reachable. The usual workaround in their community forum is to expose the local server publicly through a tunnel such as ngrok, which is the opposite of what someone running a local model is usually trying to achieve.If you want the cloud models anyway, Onyx Code takes your own OpenAI, Anthropic, Groq or Mistral key on the Free tier and calls them directly, so nothing is proxied through us. The default stays local; the cloud is a choice you make per task.
Feature comparison
Onyx rows are sourced from the Free versus Pro reference that ships with the product. Where a capability is Pro, it says so.
| Question | Onyx Code | Cursor |
|---|---|---|
| Where does inference run | On your machine, bundled engine, no setup | On Cursor’s servers |
| What leaves your machine by default | Nothing. Cloud only if you add your own API key | Prompts and code context, to Cursor and its model providers |
| Works with the network off | Yes, including agent edits | No |
| Hard switch that blocks all outbound traffic | Air-Gap Mode, three-layer enforcement, Free | Not applicable to a cloud product |
| Telemetry | None by default | Privacy Mode is opt-in for individuals, on by default for Enterprise |
| Model choice | Any GGUF you drop in, plus your own cloud keys. One chat model on Free, unlimited on Pro | Frontier models, chosen for you or by you |
| Agent mode | Ask and Edit-auto on Free. Plan, Auto and worktree sandboxing are Pro, and run on the local model | Agent on frontier models, and better at long tasks |
| Audit trail of what the AI read and wrote | AI Activity Log plus audit-PDF export, Free | No in-editor equivalent |
| Exclude paths from the AI entirely | .onyxnoai, honoured by chat, index, autocomplete and agents | Indexing ignore rules, not an AI-wide exclusion |
| Extension marketplace | Open VSX | Open VSX |
| Pricing | Free tier forever, Pro $39 once for three machines | Hobby free, Pro $20 a month |
Both editors are VS Code forks, so both use the Open VSX registry rather than Microsoft’s marketplace. That is a real limitation and it applies equally to both.
What Cursor does better
This section is here because a comparison page without it is an advertisement. These are real advantages, and for a lot of people they are the deciding ones.
- Model quality on hard problems. A frontier model reasons better than a 7B-class model running on your laptop. For a subtle refactor across an unfamiliar codebase, Cursor will more often be right first time. We do not claim otherwise, which is why Onyx Code lets you bring your own cloud key when a task deserves one.
- Tab completion. Cursor Tab is excellent, and it is trained on a scale of real edit data we cannot match.
- Long autonomous runs.The bigger the model, the further an agent can go before it needs a human. Cursor’s agent holds up over longer tasks than a local model does.
- Team and enterprise plumbing. Seat management, org policy, SOC 2, and zero-retention agreements with model providers. Onyx Code sells a one-time personal licence today and has none of that yet.
- Pace. A funded team ships features faster than a small one. If you want the newest thing the week it appears, that is not us.
Who should switch
Situations, not personas. If none of these is you, Cursor is a good product and you should keep using it.
- Your employer will not let you paste code into a cloud service, and you have been coding without AI help because of it.
- You work on a client codebase under an agreement that names third-party processors, and adding one means a conversation with legal that you would rather not have.
- You need to show an auditor what an AI tool read and wrote in your repository. The Activity Log and its PDF export exist for exactly that conversation.
- You code on planes, trains, a boat, a site with no signal, or a network that blocks everything interesting.
- You are tired of subscriptions and want the tool to keep working when you stop paying attention to it.
- Your machine has a decent GPU or Apple Silicon and it is sitting idle while you rent someone else’s.
What each actually costs
Cursor is $20 a month on the Pro plan, with a free Hobby tier and larger plans above it. Onyx Code has a Free tier that is a complete editor with local AI, and a Pro licence at $39 once, valid on three of your machines, with major version upgrades included.
The honest framing is not that one is cheap and the other expensive. A subscription buys you someone else’s GPUs and the best models on them, every month. A one-time licence buys software that runs on hardware you already own. The first is better value if you want frontier reasoning all day; the second is better value if the work you want help with is autocomplete, questions about your own codebase, and mechanical multi-file edits, which is most of the day for most people.
.onyxnoai are all Free. Pro is the agent workstation upgrade: unlimited models, project memory, Plan and Auto modes, sandboxed agent runs.Questions people ask before switching
Is Onyx Code open source?
The editor is built on VS Code OSS, which is MIT licensed. The AI layer on top is proprietary, and Pro is a paid licence. We say that plainly rather than burying it, because the alternative is you finding out later.
Can I keep my VS Code extensions?
Most of them. Like every VS Code fork, including Cursor, Onyx Codeuses the Open VSX registry because Microsoft’s marketplace is not licensed for forks. The first-run wizard imports your VS Code settings and tells you by name which of your extensions are not on Open VSX, and there is an install-from-VSIX path for the rest.
Will a local model be fast enough?
For autocomplete and next-edit prediction, yes, and often faster than a round trip to a data centre. The bundled engine uses Metal on Apple Silicon and Vulkan on NVIDIA, AMD and Intel GPUs, with an in-app Auto, GPU or CPU switch. The model is chosen for your hardware during setup rather than left to you to guess.
Do I have to install Ollama or LM Studio first?
No. The engine and a first model come with the app, which is the main practical difference between Onyx Code and the do-it-yourself local stacks. Connecting to an external Ollama, LM Studio or remote inference server is supported too, on the Pro tier.
Can I use both?
Plenty of people will. Keep Cursor for the work that benefits from a frontier model, and use Onyx Code for the repositories that are not allowed anywhere near one. They import the same settings and read the same .cursorrules file.
Try it on the repository you cannot send anywhere
Download, open a folder, ask a question. The model is already in the app, and you can do the whole thing with the Wi-Fi off.
Free tier, no account, no sign-up, no telemetry. macOS, Windows and Linux.