Model comparison
GPT-5.3 Codex vs GPT-5.6 Terra
List rate, corouter rate, context, and which ID to send for gpt-5.3-codex versus gpt-5.6-terra. A sample of 1 million input tokens plus 200 thousand output tokens is about $0.910 on corouter (input $0.350, output $0.560). A sample of 1 million input tokens plus 200 thousand output tokens is about $0.880 on corouter (input $0.400, output $0.480).
| GPT-5.3 Codex | GPT-5.6 Terra | |
|---|---|---|
| ID | gpt-5.3-codex | gpt-5.6-terra |
| Vendor | OpenAI | OpenAI |
| List input | $1.75 | $2.00 |
| corouter input | $0.350 | $0.400 |
| List output | $14.00 | $12.00 |
| corouter output | $2.80 | $2.40 |
| Cache read | $0.035 | $0.040 |
| Context | 272K | 1.1M |
Price gap
On output, GPT-5.6 Terra is lower: $2.40 on corouter versus $2.80 for GPT-5.3 Codex, about 1.17×. Input is $0.400 versus $0.350.
Window and modalities
GPT-5.6 Terra lists a 1.1M window and GPT-5.3 Codex lists 272K. A larger window does not change the per-token rate. Prompts past the window need a split or a different ID. GPT-5.3 Codex is listed with these modalities: Chat, Reasoning, Code, Vision. GPT-5.6 Terra is listed with these modalities: Chat, Reasoning, Vision.
When to send gpt-5.3-codex
GPT-5.3 Codex is a coding ID with a 272K window. Its list rate matches GPT-5.2 Codex; the difference you bill is the ID itself, gpt-5.3-codex.
Both are OpenAI IDs. The field you change is model: gpt-5.3-codex or gpt-5.6-terra.
When to send gpt-5.6-terra
GPT-5.6 Terra sits between Sol and Luna on the GPT-5.6 rate card and does not carry the Code modality tag. Send gpt-5.6-terra for long-context chat and vision at the mid rate.
Both are OpenAI IDs. The field you change is model: gpt-5.6-terra or gpt-5.3-codex.
The same volume, two bills
A sample of 1 million input tokens plus 200 thousand output tokens is about $0.910 on corouter (input $0.350, output $0.560).
A sample of 1 million input tokens plus 200 thousand output tokens is about $0.880 on corouter (input $0.400, output $0.480).
Questions
- Which output rate is lower, GPT-5.3 Codex or GPT-5.6 Terra?
- On output, GPT-5.6 Terra is lower: $2.40 on corouter versus $2.80 for GPT-5.3 Codex, about 1.17×. Input is $0.400 versus $0.350.
- Is corouter affiliated with the model vendors?
- No. corouter is not affiliated with OpenAI or Anthropic. Vendor names identify the model and the published list rate.
- How do you start billing?
- Create a console account and spend prepaid credits. The minimum top-up is $5. The API base is https://api.corouter.co. Put the ID you chose in the model field.