GPT-6 Astra vs Claude Opus 5
GPT-6 Astra is the lower-priced of the two on Router One at base-tier rates (GPT-6 Astra: request input ≤ 272,000 tokens) — about 11% less on a 1M-input + 1M-output mix. GPT-6 Astra's lower 1M-input + 1M-output total holds only for requests of up to 272,000 input tokens; above that the ordering reverses: Claude Opus 5 comes to $13.50 vs $19.00 for GPT-6 Astra. Both carry a 1.05M context window. GPT-6 Astra answers on /v1/chat/completions and /v1/responses (Codex CLI); Claude Opus 5 on /v1/chat/completions and /v1/messages (Claude Code). GPT-6 Astra counts against the Flagship models allowance on Max and Ultra; Claude Opus 5 counts against the Premium models allowance on Pro, Max and Ultra.
GPT-6 Astra and Claude Opus 5 compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.
GPT-6 Astra vs Claude Opus 5: rates, context window, and capabilities
| Spec | GPT-6 Astra | Claude Opus 5 |
|---|---|---|
| Input / 1M tokens | $2.00 | $2.25 |
| Output / 1M tokens | $10.00 | $11.25 |
| Cached input / 1M tokens | $0.20 | $0.375 |
| Context window | 1.05M | 1.05M |
| Capabilities | Chat, Streaming, Tool calling, Vision | Chat, Streaming, Tool calling, Vision |
| Subscription plans | Flagship models — Max, Ultra | Premium models — Pro, Max, Ultra |
| Detail page | GPT-6 Astra | Claude Opus 5 |
GPT-6 Astra: request input ≤ 272,000 tokens: Input $2.00 / 1M tokens, Output $10.00 / 1M tokens, Cache write $2.50 / 1M tokens, Cached input $0.20 / 1M tokens; request input > 272,000 tokens: Input $4.00 / 1M tokens, Output $15.00 / 1M tokens, Cache write $5.00 / 1M tokens, Cached input $0.40 / 1M tokens. The total input tokens in each request select the tier; its rates apply to the whole request, not only tokens above the threshold.
What does 1M tokens cost on GPT-6 Astra vs Claude Opus 5?
Base-tier rates: For a workload of 1M input plus 1M output tokens at current rates: GPT-6 Astra comes to $12.00, Claude Opus 5 comes to $13.50 — GPT-6 Astra is about 11% cheaper on this mix. Real workloads skew heavily toward input tokens, so weigh the input rate by your own ratio; the cached-input row above is the posted catalog rate for that model.
Switch between GPT-6 Astra and Claude Opus 5
The API key and base URL stay the same, but this is not a one-string switch for every request. Per OpenAI's GPT-6 guide (checked 2026-10-01), GPT-6 Astra takes tool calls only on the Responses API, does not accept the none reasoning effort (OpenAI suggests low) and takes no temperature, top_p or logprobs settings. Router One serves Claude Opus 5 on /v1/messages and /v1/chat/completions, not on /v1/responses. So tool-using code has to change path as well as model: Codex CLI (/v1/responses) runs only the GPT side and Claude Code (/v1/messages) only the Claude side. On a Pro, Max or Ultra plan the billing changes too: as of the 2026-10-01 plan response, GPT-6 Astra counts against the Flagship models allowance on Max and Ultra (on Pro it bills the wallet), while Claude Opus 5 counts against the Premium models allowance on Pro, Max and Ultra.
curl https://api.router.one/v1/chat/completions \
-H "Authorization: Bearer sk-your-router-one-key" \
-H "Content-Type: application/json" \
-d '{"model": "openai/gpt-6-astra", "messages": [{"role": "user", "content": "Hello"}]}'
# Same request, other model — change one string:
# "model": "anthropic/claude-opus-5"FAQ
Is GPT-6 Astra cheaper than Claude Opus 5?
Compared at base-tier rates (GPT-6 Astra: request input ≤ 272,000 tokens). Input: GPT-6 Astra $2.00 vs Claude Opus 5 $2.25 / 1M tokens; GPT-6 Astra has the lower rate. Output: GPT-6 Astra $10.00 vs Claude Opus 5 $11.25 / 1M tokens; GPT-6 Astra has the lower rate. GPT-6 Astra's lower 1M-input + 1M-output total holds only for requests of up to 272,000 input tokens; above that the ordering reverses: Claude Opus 5 comes to $13.50 vs $19.00 for GPT-6 Astra. Total cost depends on the workload's input, output and cache usage. GPT-6 Astra: request input ≤ 272,000 tokens: Input $2.00 / 1M tokens, Output $10.00 / 1M tokens, Cache write $2.50 / 1M tokens, Cached input $0.20 / 1M tokens; request input > 272,000 tokens: Input $4.00 / 1M tokens, Output $15.00 / 1M tokens, Cache write $5.00 / 1M tokens, Cached input $0.40 / 1M tokens. The total input tokens in each request select the tier; its rates apply to the whole request, not only tokens above the threshold. Rates change; the /models page is the live source of truth.
Is GPT-6 Astra or Claude Opus 5 included in a Router One subscription?
GPT-6 Astra counts against the Flagship models allowance on Max and Ultra: Max 150 and Ultra 450 requests per 30-day cycle, shared by every model in that tier. Claude Opus 5 counts against the Premium models allowance on Pro, Max and Ultra: Pro 300, Max 1,000 and Ultra 5,000 requests per 30-day cycle, shared by every model in that tier. Requests to GPT-6 Astra or Claude Opus 5 above the model's long-context threshold count as more than one quota request. Requests beyond a plan's allowance bill the wallet per token.
Can I switch between GPT-6 Astra and Claude Opus 5 without changing code?
The API key and base URL stay the same, but this is not a one-string switch for every request. Per OpenAI's GPT-6 guide (checked 2026-10-01), GPT-6 Astra takes tool calls only on the Responses API, does not accept the none reasoning effort (OpenAI suggests low) and takes no temperature, top_p or logprobs settings. Router One serves Claude Opus 5 on /v1/messages and /v1/chat/completions, not on /v1/responses. So tool-using code has to change path as well as model: Codex CLI (/v1/responses) runs only the GPT side and Claude Code (/v1/messages) only the Claude side. On a Pro, Max or Ultra plan the billing changes too: as of the 2026-10-01 plan response, GPT-6 Astra counts against the Flagship models allowance on Max and Ultra (on Pro it bills the wallet), while Claude Opus 5 counts against the Premium models allowance on Pro, Max and Ultra.
Where do these numbers come from?
Specs and prices on this page render from the live Router One catalog — the same data as the /models page — and refresh with it. Pricing methodology is documented on /pricing-methodology. Rates on this page were read from the live catalog on 2026-10-22 (UTC) and refresh within the hour.