Claude Fable 5.1 vs GPT-6 Astra
The listed rates and 1M-input + 1M-output workload example use base tiers, assuming every request meets: openai/gpt-6-astra: request input ≤ 272,000 tokens. Requests above a threshold use the long-context rates below. GPT-6 Astra is the lower-priced of the two on Router One — about 75% less on a 1M-input + 1M-output mix. Both carry a 1.05M context window. Claude Fable 5.1 answers on /v1/chat/completions and /v1/messages (Claude Code); GPT-6 Astra on /v1/chat/completions and /v1/responses (Codex CLI).
Claude Fable 5.1 and GPT-6 Astra compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.
Claude Fable 5.1 vs GPT-6 Astra: rates, context window, and capabilities
| Spec | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|
| Input / 1M tokens | $8.00 | $2.00 |
| Output / 1M tokens | $40.00 | $10.00 |
| Cached input / 1M tokens | $0.80 | $0.20 |
| Context window | 1.05M | 1.05M |
| Detail page | Claude Fable 5.1 | GPT-6 Astra |
openai/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 Claude Fable 5.1 vs GPT-6 Astra?
The listed rates and 1M-input + 1M-output workload example use base tiers, assuming every request meets: openai/gpt-6-astra: request input ≤ 272,000 tokens. Requests above a threshold use the long-context rates below. For a workload of 1M input plus 1M output tokens at current rates: Claude Fable 5.1 comes to $48.00, GPT-6 Astra comes to $12.00 — GPT-6 Astra is about 75% 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 Claude Fable 5.1 and GPT-6 Astra without changing code
Both models are behind the same OpenAI-compatible endpoint, so an A/B test is a one-string change — same key, same code, and every request traced with tokens, cost, and latency in the dashboard:
curl https://api.router.one/v1/chat/completions \
-H "Authorization: Bearer sk-your-router-one-key" \
-H "Content-Type: application/json" \
-d '{"model": "anthropic/claude-fable-5.1", "messages": [{"role": "user", "content": "Hello"}]}'
# Same request, other model — change one string:
# "model": "openai/gpt-6-astra"FAQ
Is Claude Fable 5.1 cheaper than GPT-6 Astra?
The listed rates and 1M-input + 1M-output workload example use base tiers, assuming every request meets: openai/gpt-6-astra: request input ≤ 272,000 tokens. Requests above a threshold use the long-context rates below. Input: Claude Fable 5.1 $8.00 vs GPT-6 Astra $2.00 / 1M tokens; GPT-6 Astra has the lower rate. Output: Claude Fable 5.1 $40.00 vs GPT-6 Astra $10.00 / 1M tokens; GPT-6 Astra has the lower rate. Total cost depends on the workload's input, output and cache usage. openai/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.
Can I switch between Claude Fable 5.1 and GPT-6 Astra without changing code?
Yes. Both are served through the same OpenAI-compatible endpoint, so switching is changing the model string in the request — the key, base URL, and request shape stay identical.
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 2026-09-07 (UTC) and refresh within the hour.