# Gemini 4 Carbon

> Gemini 4 Carbon, released by Google on November 10, 2026, targets deep work on complex tasks. Google names coding, finance, legal work, cybersecurity and science among its intended domains. Use the model ID gemini-4-carbon when you want to evaluate sustained analysis, difficult reasoning or a workflow that repeatedly calls tools. Hydrogen is the sibling to compare when everyday coding, speed and efficiency matter more to the task.

Canonical: https://routemux.com/google/gemini-4-carbon
Provider: Google

## Key facts

| Field | Value |
| --- | --- |
| Model ID | google/gemini-4-carbon |
| Official model ID | gemini-4-carbon |
| Context window | 1M |
| Max output | 1M |
| Input modalities | text, image, audio |
| Output modalities | text |
| Capabilities | Vision, Reasoning, Tool Calling, Json Mode, Coding, Audio Input |
| Upstream release | 2026-11-10 |
| Availability | available |

## Pricing

- RouteMux input: $1 per 1M tokens
- RouteMux output: $5 per 1M tokens
- Official input: $2 per 1M tokens
- Official output: $10 per 1M tokens
- Cache read: $0.05 per 1M tokens
- Saving vs official: 50%
- Official price source: https://cloud.google.com/model-garden/pricing, verified 2026-11-14

Billing is prepaid wallet, charged per successful request only.

## API access

Base URL: https://api.routemux.com

Supported protocols:

- openai_chat
- openai_responses
- anthropic_messages

Aliases that also route here: models/gemini-4-carbon

## What is Gemini 4 Carbon

Gemini 4 Carbon, released by Google on November 10, 2026, targets deep work on complex tasks. Google names coding, finance, legal work, cybersecurity and science among its intended domains. Use the model ID gemini-4-carbon when you want to evaluate sustained analysis, difficult reasoning or a workflow that repeatedly calls tools. Hydrogen is the sibling to compare when everyday coding, speed and efficiency matter more to the task.

Carbon has a single 1,048,576-token budget shared by input, thinking, function calls and the final answer. Its thinking levels are low, medium and high, with medium as the default. Custom temperature, top_p and top_k values are ignored. Moving from Gemini 3.x therefore requires checking sampling-dependent behavior and using thinking levels to vary reasoning effort.

RouteMux exposes OpenAI Chat Completions and Anthropic Messages with streaming, ordinary function tools and Base64 image input. Image understanding does not generate images. Office documents, audio, video and hosted tools available through Google's native APIs are separate from this compatibility surface. One Carbon request produces at most 65,536 output tokens when streaming, or 32,768 without streaming. Thinking consumes that output allowance. Google's million-token output figure requires continuation across segments, rather than one ordinary API response.

RouteMux input costs $1 per million tokens and output costs $5 per million tokens.

## Key capabilities

- **Reasoning for complex work** — Google positions Carbon for deep work across several domains. Compare low, medium and high on your own tasks instead of applying one thinking setting everywhere.
- **One shared token window** — Long source files, tool history, thinking and answers consume the same 1,048,576-token window. More input leaves less room for reasoning and output.
- **Tools and image understanding** — Chat Completions and Messages accept ordinary function tools and Base64 images, allowing screenshot observations and tool results to participate in multi-turn workflows.
- **Implicit caching, fixed sampling** — Google offers implicit caching for eligible prompts of at least 4,096 tokens. Custom temperature, top_p and top_k values are ignored.

## Use cases

- **Complex software engineering** — A core use named by Google: reason over substantial code, plan changes through multiple tool steps and check the results.
- **Professional analysis** — Google includes finance and legal work among its intended domains. Analyze supplied material with domain experts reviewing the conclusions.
- **Science and security research** — Google also names science and cybersecurity, including analysis that needs several reasoning steps and supporting tools.

## Other variants in this family

- Gemini 4 Argon (`google/gemini-4-argon`)
- Gemini 4 Hydrogen (`google/gemini-4-hydrogen`)

## Sources

- [Google: Gemini 4 Carbon model documentation](https://docs.cloud.google.com/gemini-enterprise-agent-platform/models/gemini/4-carbon)
- [Google: Get started with Gemini 4](https://docs.cloud.google.com/gemini-enterprise-agent-platform/models/start/get-started-with-gemini-4)