# Google tests Gemini 4 “Carbon” model on internal coding platform

> Google employees say the new Carbon variant of Gemini 4 matches Anthropic’s Opus 5.5 on coding tasks, but it is still in internal testing.

Oossa · 2026-10-10 · https://oossa.com/en/google-tests-gemini-4-carbon-model-on-internal-coding-platform

Google is running a Gemini 4 variant called Carbon on its internal Jetski coding platform. Internal chats seen by Business Insider say Carbon performed on par with Anthropic’s Opus 5.5, the company’s top coding model. Carbon is part of the Argon family, which also includes Barium and the upcoming Argon model. The testing is still internal, and Google has not announced a public release date.

## The facts

- Carbon was deployed on Jetski in the past few days, according to internal documents.
- An employee compared Carbon’s coding performance to Anthropic’s Opus 5.5.

## Why it matters

If Carbon reaches public release, developers could get a new high‑perform coding assistant from Google comparable to Anthropic’s best offering.

## Sources & references

1. [Google's Gemini 4 "Carbon" model is reportedly matching Anthropic's Opus 5.5 coding performance](https://the-decoder.com/googles-gemini-4-carbon-model-is-reportedly-matching-anthropics-opus-5-5-coding-performance/) – The Decoder, 2026-10-10

Last updated: 2026-10-10