Claude Sonnet 5 vs Claude Opus 5 vs Claude Fable 5.1
Pick two to four models to compare benchmark scores, prices, context windows and speed. The link updates as you pick, so you can share the exact comparison.
Cheapest blended
Claude Sonnet 5
$4.00 / 1M tokens
Largest context
Claude Sonnet 5Claude Opus 5Claude Fable 5.1
Tie at 1M tokens
Fastest output
Claude Sonnet 5
85 tokens/s
Top on Terminal-Bench 4.0
Claude Fable 5.1
55.8%
Specifications
| Spec | Claude Sonnet 5Anthropic | Claude Opus 5Anthropic | Claude Fable 5.1Anthropic |
|---|---|---|---|
| Provider | Anthropic | Anthropic | Anthropic |
| Released | 30 Jun 2026 | 24 Jul 2026 | 1 Sep 2026 |
| Licence | Proprietary | Proprietary | Proprietary |
| Context window | 1M tokens | 1M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens | 128K tokens |
| Input / 1M | $2.00* | $5.00* | $10.00* |
| Output / 1M | $10.00 | $25.00 | $50.00 |
| Cached input / 1M | $0.20 | $0.50 | $0.25 |
| Speed | 85 tokens/s | 55 tokens/s | 68 tokens/s |
| Input types | text, image | text, image | text, image |
| Best for | CodingAgentsBudget | CodingAgentsReasoning | ReasoningAgentsCodingResearch |
* Claude Sonnet 5: $2/$10 launched as introductory pricing through 31 Aug 2026 and is now the standard price; the planned rise to $3/$15 on 1 Sep 2026 did not happen. Uses the newer tokenizer (launch post: roughly 1.0–1.35x more tokens depending on content). Minimum cacheable prompt: 1,024 tokens.
* Claude Opus 5: Legacy; Opus 5.5 is cheaper ($4/$20). Fast mode (research preview, Claude API only): $10 input / $50 output. Uses the newer tokenizer. Safety classifiers can refuse; since 24 Sep 2026 some pre-output refusal categories are billed. Minimum cacheable prompt: 512 tokens.
* Claude Fable 5.1: Cache reads are 0.025x base input ($0.25), down from $1 on Fable 5. Uses the newer tokenizer (about 30% more tokens than pre-Opus 4.7 models for the same text). Safety classifiers can refuse; since 24 Sep 2026 pre-output refusals in the bio, frontier_llm and reasoning_extraction categories are billed. Minimum cacheable prompt: 512 tokens.
Benchmark scores
Officially reported scores only. A model with no published score on a benchmark shows a line, not a zero.
Price per 1M tokens
Context window and speed
Notes
- Claude Sonnet 5
- Legacy Sonnet model, superseded by Claude Sonnet 5.5. Anthropic called it the most agentic Sonnet model yet, with performance close to Opus 4.8 at lower prices.
- Claude Opus 5
- Legacy Opus model, superseded by Claude Opus 5.5. Anthropic described it as coming close to Claude Fable 5's intelligence at half the price, designed for everyday use.
- Claude Fable 5.1
- Anthropic's top generally available model, for demanding reasoning and long-horizon agentic work. Successor to Claude Fable 5 at the same input and output prices, with stronger long-running agentic coding, multistep research and document work.
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