Anthropic14 cases
Claude Opus 5.5
Explore source-linked coding projects, 3D worlds, research workflows and autonomous agents.
1M context · $4 input / $ 20 output per 1M tokens
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Model facts, source-linked projects and usable prompts. Start with Claude Opus 5.5, or compare the models behind your coding workflow.
Anthropic
Claude Opus 5
The previous Opus generation: a baseline for evaluating an Opus 5.5 migration.
1M context · $5 input / $ 25 output per 1M tokens
Explore modelAnthropic
Claude Fable 5.1
Compare Fable's capacity, API cost and reported results with the current Opus model.
1M context · $10 input / $ 50 output per 1M tokens
Explore modelOpenAI
GPT-6 Astra
OpenAI's model for complex reasoning, coding and computer use, alongside Claude in shared comparisons.
1.05M context · $10 input / $ 50 output per 1M tokens
Explore modelImage models
Nano Banana 2.1
Google's high-efficiency image generation and editing model
$0.0336 per 1K image · 1K · 2K · 4K
Read the complete guideSpecs and API pricing
| Model | Context | Max output | Input | Output | Cache read |
|---|---|---|---|---|---|
| Claude Opus 5.5Anthropic | 1M | 128K | $4 | $20 | $0.2 |
| Claude Opus 5Anthropic | 1M | 128K | $5 | $25 | $0.5 |
| Claude Fable 5.1Anthropic | 1M | 128K | $10 | $50 | $0.25 |
| GPT-6 AstraOpenAI | 1.05M | 128K | $10 | $50 | $1 |
Standard rates in USD per 1M tokens. Long-context and batch pricing can differ; each model page links to the official pricing conditions.
Launch benchmarks
| Benchmark | Claude Opus 5.5 | Claude Opus 5 | Claude Fable 5.1 | GPT-6 Astra |
|---|---|---|---|---|
| Terminal-Bench 4.0Opus 5.5: xhigh effort | 66.4% | 52.3% | 55.8% | 57.9% |
| FrontierCode v1.1Opus 5.5: max effort | 54.4% | 48% | 50.3% | 53.3% |
| CursorBench 4.0Opus 5.5: max effort | 57.8% | 46.6% | 51.8% | Not reported |
| GDPval-AA v2.1Opus 5.5: max effort | 1846 Elo | 1708 Elo | 1735 Elo | 1542 Elo |
| AutomationBenchOpus 5.5: max effort | 40% | 26.9% | 31.4% | 41.4% |
| Humanity's Last ExamWith tools · Opus 5.5: max effort | 67.7% | 63.6% | 65.6% | 57.2% |
Vendor-reported launch results, September 22, 2026. Opus 5.5 uses max effort except Terminal-Bench (xhigh). Other models' effort, harness and tool settings can differ; see the original methodology. These are not AI IDE List tests and are separate from Anthropic's medium-effort cost charts.
Benchmark source and methodologyModel comparisons
Claude Opus 5.5 vs Claude Opus 5
Opus 5.5 lowers standard input and output token prices by 20%. Use Opus 5 as a baseline and check for regressions on your existing tasks.
Claude Opus 5.5 vs Claude Fable 5.1
Both offer a 1M context window and 128K output. Opus 5.5 has 60% lower standard input and output rates; the best choice still depends on task quality.
Claude Opus 5.5 vs GPT-6 Astra
Opus 5.5 has lower standard token rates; Astra offers a slightly larger context window. Compare API tooling, long-context pricing and your own task results.
API facts reviewed 2026-09-25. Each model page links to official specifications and pricing conditions.