Onyx Code vs GitHub Copilot

The short answer

Copilot can drive a local model now, and that deserves saying out loud. What it will not do locally is the thing you use most: inline completions still need a GitHub account and an internet connection.

Copilot can use a local model. Here is what you lose when you do

VS Code’s own documentation is clear that a locally hosted model works without a GitHub account, without a Copilot plan and without an internet connection. If someone tells you Copilot is cloud-only, they are out of date, and we are not going to pretend otherwise on this page.

The same documentation is equally clear about the limits. Semantic search, inline suggestions and anything that relies on embeddings require a GitHub account and internet connectivity. In practice that means the local-model path gives you chat, and takes away autocomplete and codebase search: the two features most developers use most often.

In Onyx Code, autocomplete, next-edit prediction, codebase indexing, retrieval and the agent all run against the local engine. There is no feature that quietly needs an account, because there is no account.

Feature comparison

The Copilot column describes Copilot in VS Code, its most common home. Where the answer differs between the cloud path and the bring-your-own local-model path, both are given.

What GitHub Copilot does better

Copilot is the default for a reason, and several of those reasons are things we do not do at all.

• It lives where your work lives. Pull request summaries, review comments, issues, the CLI and the web. If your team runs on GitHub, that integration is worth more than any single editor feature.
• Frontier model quality. On hard reasoning, a large hosted model beats a model running on your laptop. Onyx Code answers this by letting you bring your own cloud key when a task deserves one, not by pretending the gap is not there.
• You keep Microsoft’s extension marketplace. Copilot is an extension inside real VS Code, so nothing about your setup changes. Every VS Code fork, Onyx Code included, has to use Open VSX instead.
• Organisation-wide policy. Seat management, enterprise controls and exclusions set centrally by owners. Our licence is a one-time personal one today.
• It is already approved. If your employer has cleared Copilot, using it costs you no paperwork. That is a real advantage and we are not going to argue with it.

Who should switch

• You tried the local-model route in VS Code, and found that losing autocomplete and codebase search made it not worth it.
• Your organisation has not approved Copilot, and the reason is that code would leave the network.
• You need path exclusions that the agent honours too, and control of them that does not depend on being a repository or organisation owner.
• You have to evidence what an AI tool touched. An Activity Log you can export as a PDF is a shorter conversation than a vendor policy document.
• You work disconnected often enough that a tool which quietly stops helping is worse than no tool.
• You are paying a monthly subscription for autocomplete you could be running on a GPU you already own.

Questions people ask before switching

Can I keep Copilot and use Onyx Code too?

Yes, and for many people that is the sensible answer. Keep Copilot in VS Code for GitHub work, and use Onyx Code for the repositories that are not allowed to reach a cloud service. Your settings import on first run.

Is this another VS Code fork that falls behind?

It is a fork of VS Code OSS, rebased on upstream releases. The version extensions see is tracked separately from the product version, so an extension that asks for a given VS Code version gets a truthful answer.

What about my extensions?

Open VSX carries most of the popular ones. Microsoft’s marketplace is not licensed for forks, so this applies to Cursor, Windsurf and every other fork as well. The first-run wizard lists by name which of your extensions are missing, and there is an install-from-VSIX path.

Do I need a GitHub account?

No. Onyx Code has no account at all on the Free tier. A Pro licence is activated with a code and an email confirmation, and works on three machines.

Is the local model good enough to replace Copilot completions?

For fill-in-the-middle completion and next-edit prediction, current small code models are good and, running locally, usually faster than a round trip. For hard multi-step reasoning they are not a frontier model, which is why bringing your own cloud key is supported on the Free tier.